摘要:

J O U R N A L OF THE CHEMICAL SOCIETY. H. E. ARXSTRONG Ph.D. F.R.S. W. CROOKES F.R.S. A. DUPRB Ph.D. F.R.S. %. FRANKLAND D.C.L. F.lt.S. C. GRAHAM D.Sc. C. W. HEATON F.C.S. HUGO MULLER Ph.D. F.R.S. W. H. PERKIN F.R.S. H. E. ROSCOE LL.D. F.R.S. W. J. RUSSELL Ph.D. F.R.S. C. R. A. WRIGHT D.Sc. @;bitax : HENRY WATTS B.A. F.R.S. SIxb-@,bifar : C . E. GROVES F.C.S. VOl. XXXVII. 1880. TRANSACTIONS. L O N D O N : J. V A N VOORST 1 P A T E E N O S T E R ROW. 1880 LONDON : IIARRTSON AND SONS PRINTERS IN ORDINARY TO HER MAJESTY ST. MARTIN’S LANE C O N T E N T S . PAPERS READ BEFORE THE CHEMICAL SOCIETY. PAGE 1.-A Chemical Study of Vegetable Albinism. Part 11. Respira-tiou and Transpiration of Albino Foliage. By A. H CHURCH Professor of Chemistry at the Royal Academy of Arts in London .. 1 11.-On a-Methyl-hydroxysucciriic Acid the product of the Action of Anhydrous Hydrocyanic Acid upon Ethyl Aceto-acetatre. By GEORGE H. MORRIS. . . 6 Part I. By C. T. KINGZETT . . 15 By C. R. ALDER WRIGHT, l3.S~. (Lond.) Lecturer on Chemistry in St. Mary’s Hospital Medical School ; and A. E. MENKE Daniell’s Scholar King’s V.-The Comparative Value of Different Methods of Fractional VI. Coiitributions from the Laboratory of Gonville and Caius College Cambridge No. III. On the influence exerted upon the Course of Certain Chemical Changes by Varia-tions in the Amount of Water of Dilution. By M. M. PAT-TISON k U I R Caius Prekctor in Chemistry; and CHAS. SLATER B.A. Scholar of St. John’s College . . 60 VI1.-On a- and p-Phenanthrene-cnrboxylic Acids with Re-marks on the Constitution of Phenanthrene.By FRANCIS R. JAPP MA. Ph.D. Assistant in the Chemical Research VII1.-On some Derivatives of Phenylacetic Acid. By P. PHILLIPS BEDSON D. Sc. Assistant Lecturer and Demon-1X.-On the Specific Volume of Water of Crystallisation. By X.-Note on the Formation of Ozone during the Slow Oxida-XI.-On the Analysis of Organic Bodies containing Nitrogen, X1I.-The Blleltiitg and Boiling Points of cei-tain Inorganic Substances. By T. CARNELLEY D.Sc. Professor of 111.-Contributions to the History of Putrefaction. 1V.-Notes on Manganese Dioxide. College . . 22 Distillation. By FREDERICK D. BROWN B.Sc. . 49 Laboratory Science Schools South Kensington . . 83 strator in Chemistry at the Owens College .. 90 T. E. THORPE F.R.S. and JOHN I. WATTS . . 102 tion of Phosphorus. By HEPBERT MCLEOD . . 118 &c. By W. H. PERKIN F.R.S. . 12 iv CONTENTS. Chemistry Firth College Sheffield and W. CARLETON-WILLIAMS Assistant Lecturer on Chemistry Owens College XII1.-On the Reaction between Sodium Thiosulphate and Iodine. Estimation of Manganese Oxides and Potassium Bichromate. By SPENCER UMFREVILLE PICKERING Bracken-bury Scholar of Rnlliol College Oxford X1V.-A New and Simple Apparatus for the Treatment of Substances in Open Dishes by Volatile Solvents. By A. WYNTER BLYTH . XV.-On the Relation between the Molecular Weights of Sub-stances and their Specific Gravities when in the Liquid State. By T. E. THORPE Ph.D. F.R.S. . XV1.-Contributions from the Laboratory of the Unirersity of T6ki6 Japan 11.On Perthiocyanate of Silver. By R. W. ATKINSON, B.Sc. (Lond.) Professor of Analytical and Applied Chemistry in the University . By H. P. MORLEY, M.A. . . XVI1.-On Methylated Dioxethylenamines. XVII1.-Note on Igasurine. By W. A. Shenstone . X1X.-On some Reactions of Tertiary Butyl Iodide. By (Frankland Prize of the Institute of LEONARD DOBBIK. Chemistry) . . Anniversary Meeting . . XX.-River Water. By C. MEYMOTT TIDY M.B. M.A. M.S. . XX1.-On the Relation between the Molecular Weights of Substances and their Specific Gravities when in the Liquid State. By T. E. THORPE Ph.D. F.R.S. . XXI1.-Contributions to the History of the Orcins. Betorcinol and some of its Derivatives. By JOHN STENHOUSE LL.D., P.R.S.and CHARLES E. GROVES XXII1.-On the Action of Organo-zinc Compounds on Qui-nones. (Second Notice.) By FRANCIS R. JAPP M.A., Ph.D. Demonstrator in the Chemical Research Laboratory, Science Schools South Kensington . By WATSON SMITH F.C.S. F.I.C. De-monstrator and Assistant Lecturer on Chemistry in the Owens College and GEORGE WM. DAVIES . XXV.-Analyses of the Ash of the Wood of Two Varieties of the Eucalyptus. By WArsoN SMITH F.C.S. F.I.C. De-monstrator and Assistant Lecturer in the Owens College, Manchester . XXV1.-On the Reflection from Copper and on the Colorimetric Estimation of Copper by means of the Reflection Cupri-meter. By THOMAS BAYLEY . XXIV.-On Pyrene. PAQE 125 128 140 141 226 232 235 236 247 268 32 7 395 408 413 416 41 CONTENTS.V XXVI1.-Note on the Products of Combustion of Coal Gas. By LEWIS T. WRIGHT . XXVII1.-Contributions from the Laboratory of Gonville and Caius College Cambridge. No. V. “Note on Chemical Equilibrium.” By M. M. PATTISON MUIR M.A. F.R.S.E. . XX1X.-On the Influence of the Amido-group upon the Orien-tation of Bromine or NO in the Benzene-nucleus as illus-trated by the preparation of the six possible Dibromotoluenes, the six possible Tribromotoluenes the three possible Tetra-bromotoluenes and various other Bromo- and Bromonitro-derivatives of Toluene. By R. H. C. NET~LE and A. WINTRER . XXX.-On the Lecture-Illustration of Chemical Curves. By EDMUND J. ISII~LLS D.Sc. F.R.S. XXX1.-On the Analysis of Organic Bodies containing Nitro-gen (continued).By W. H. PERKIN F.R.S. . XXXI1.-On Polysulphides of Sodium. Part I. Sodium Pentasulphide. By H. CHAPMAN JONES . XXXII1.-On the Determination of Nitric Acid as Nitric Oxide, by means of its Reaction with Ferrous Salts. Part I. By XXX1V.-Preliminary Notice on the Action of Sodium on some By W. R. HODGKIN-XXXV.-On the Action of Sodium on Phenylic Acetate. By W. H. PERKIN jun. and W. R. HODGKINSON XXXV1.-Note on an Improved Form of Oven for Heating Sealed Tubes and avoiding Risks of Expiosions. By WATSON SMITH F.C.S. P.I.C. Assistant Lecturer and Demonstrator in Chemistry in the Owens College XXXVI1.-Note on a Convenient Form of Lead-bath for Victor Meyer’s Apparatus for Determining the Vapour-densities of High-boiling Substances together with a few Slight Modifications.By WATSON SMITH F.C.S. F.I.C., Assistant Lecturer and Demonstrator in Chemistry in the XXXVI11.-On the Mode of Application of Pettenkofer’s Pro-cess for the Determination of Carbonic Acid in Expired Air. By WILLIAM MARCET M.D. F.R.S. F.C.S. . XXX1X.-Determination of Nitrogen in Carbon Compounds. By CHARLES E. GROVES XL.-On the Action of Air upon Peaty Water. By Miss LUCY HALCROW and E. FRANKLAND F.R.S. . XL1.-On the Spontaneous Oxidation of Organic Matter in JTTater. By X. FRANKLAND F.R.S . . ROBERT WARINGTON . Ethereal Salts of Phenylacetic Acid. SON . . . Owens College . . . PAGE 422 424 429 4P53 45 7 461 468 481 487 490 491 493 500 506 51 XLIL-On some Products of the Oxidation of Paratoluidine.By W. H. PERKIN F.R.S. . XLII1.-On Dibromanthraquinones and the Colouring Matters derived from them. By W. H. PERKIN F.R.S. . XL1V.-On the Action of Organo-zinc Compounds upon Nitriles and their Analogues. By E. FRANKLAND F.R.S. . 1. Action of Zinc-ethyl on Azobenzene. By E. FRANK-LAND F.R.S. and D. A. Lours Esq. 2. On the Action of Zinc-ethyl upon Benzonitrile. By E. FRANKLAND F.R.S. and JOHN CASTELL EVANS Esq. . . 3. Action of Zinc-ethyl on Phenylacetonit(ri1e. By E. FRANKLAND F.R.S. and HARRY K. TOMPKINS Esq. . XLV.-On a New Method of preparing Dinitroethylic Acid. By E. FRANKLAND F.R.S. and C. COLBORNE GRAHAM Esq. . XLV1.-The Detection of Foreign Colouring Matters in Wine. By A. DUPE& Ph.D. F.R.S. XLVI1.- On a Simple Method of Determining Vapour-densities in the Barometric Vacuum.By CHICHESTER A. BELL A.B. and M.B. and FRANK L. TEED F.C.S XLVII1.-On a Crystal of Diamond. By HARRY BAKER Dalton Scholar in the Chemical Laboratories of the Owens Col-lege XL1X.-On some Higher Oxides of Manganese and their Hydrates. By V. H. VELET B.A. Christ Church Labora-tory Oxford . &.-On Pentathionic Acid. By T. TAKAMATSU alnd WATSON SMITH Demonstrator and Assistant Lecturer on Chemistry in the Owens College . . By C. R. ALDER. WRTGHT D.Sc. (Lond.) Lecturer on Che-mistry and E. H,. RENNIE M.A. (Sydney) B.Sc. (Lond.), Demonstrator of Chemistry in St. Mary’s Hospital Medical School . LI1.-Notes on the Purple of the Ancients (continuation). By EDWARD SCHUNCK Ph.D. F.R.S. LII1.-On the Determination of Carbon in Soils.B-y R. WARING-. . LI-On the Action of Benzoyl Chloride on Morphine. . LI7 LV LV PAGE 546 554 560 560 563 566 5 70 5 72 5 76 5 $9 581 592 609 61 3 TON and W. A. PEAKE . . 617 .-On the Formation of Amidosulphonic Acids by the Action of Concentrated Sulphuric Acid. By R. H. C. NEVILE and A . WINTHEE . . 625 -On the Action of Ammonia and the Amines upon Naph-thoquinone. By R. T. PLIMPTOX Ph.D. . . 633 .-Experiments on Germinating Barley. By T. CCTHBEBT DAY . . 64 CONTENTS. vii PAGE LVI1.-On Metallic Compounds containing Bivalent Hydrocar-bon-radicals. By J. SAKURAI Clothworker Scholar Univer-sity College London . . 658 LVII1.-On the Action of Benzaldehyde on Phenanthraqui-none both alone aud in presence of Ammonia.By FRANCIS R. JAPP M.A. Ph.D. Demonstrator in the Oheniical Research Laboratory Science Schools South Kensington and EDGAR WILCOCK . . 661 L1X.-On a New Boro-copper Compound of the Formula B2Cu3. By R. SYDNEY MARWEN D.Sc. F.R.S.E. F.C.S. . 672 LX.-Note on the Precipitation of Iron with Ammonium Sue-cinate. By SYDNEY YO'JNG Student in the Chemical Labo-LXT.-An Examination of Terpenes for Cymene by means of the Ultra-violet Spectrum. By W. N. HARTLEY F.R.S.E. &c., Professor of Chemistry Royal ColIege of Science Dublin . LXI1.-Contributions from the Laboratory of Gonville and Caius College Cambridge. No. VJ. On Essential Oil of Sage. By M. M. PATTISON MUIR F.R.S.E. Caius Prdector in Chemistry . . 678 LXII1.-On the Synthetical Production of New Acids of the Pyruvic Series.By L. CLATSEN Ph.D. and E. MORITZ . 691 LX1V.-Contributions from the Laboratory of the Royal College of Chemistry. On the Action of Nitric Acid on Diparatolyl-guanidine. By A. G. PERKIN . . 696 LXV.-Action of Heat on the Mixed Vapours of Benzene and Toluene. Two New Methylene-diphenylenes. By THOS. CARNELLEY D.Sc. Professor of Chemistry in Firth College, Sheffield . . 701 LXV1.-Contributions from the Laboratory of the Royal College of Chemistry Science Schools South Kensington. On the Action of Benzyl Chloride on Phenyl Acetate. By W. H. PERKIN Junior Assistant and llT. R. HODGKINSON Ph.D., F.I.C. &c. Chemical Demonstrator . . 721 LXVI1.-On the Sulphides of Vanadium. By WILLIAM E.KAY, Dalton Chemical Scholar in the Owens College . . . 728 LXVII1.-On the Action of Organo-zinc Compounds upon Nitriles and their Analogues. (Second 'Notice.) By E. FRANKLAND F.R.S. and C. COLBORNE GRAHAM A.I.C. . 740 LX1X.-Action of Zinc-ethyl on Benzoylic Cyanide. By E LXX.-On the Action of Diazonaphthalene upon Salicylic Acid. By PERCY F. FRANKLAND Ph.D. . . 746 LXX1.-Acetylorthoamidobenzoic Acid. By P. P. BEDSON D.Sc. (Lond.) Assistant Lecturer and Demonstrator in Chemistry in the Owens College and A. J. KING B.Sc. . . 752 ratories of the Owens College . . 674 676 FRANKLAND F.R.S. and D. A. LOUIS Esq. . . 74 viii CONTENTS. PAQE LXXI1.-Fourth Report to the Chemical Society on “ Researches on some Points in Chemical Dynamics.” Section I. By C. R. ALDER WRIGHT D.Sc. London Lecturer on Chemistry; and E. H. REKNIE M.A. (Sydney) B.Sc. (London) Demon-strator of Chemistry in St. Mary’s Hospital Medical School. Sections I1 and 111. By C. R. ALDER WRIGHT and A. E. MENKE . . . . . 757 LXXII1.-Report on the Atmospheric Oxidation of Phosphorus and some Reactions of Ozone and Hydric Peroxide. By C. T. KINGZETT F.I.C. F.C.S. . . 792 LXS1V.-On the Basic Sulphates of Iron. By SPENCER UMFREVILLE PICBERING Brackenbury Scholar of Balliol College Oxford . . . 807 LXXV.-On the Colour-properties and Relations of the Metals, Copper Nickel Cobalt Iron Manganese and Chromium. By THOMAS BAYLEY . . 82

ISSN:0368-1645    

DOI:10.1039/CT88037FP001

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

G MORRIS ON c~-METHYL-I~YDROXTSUCCINIC ACID ETC. II.-On cc-Met7~21l-hydrozysuccinic A.cicl the p-oclzcct of the Actioqz oj’ Anhydrous Hydrocyanic Acid upon Ethyl Aceto-acetate. By GEORGE H. MORRJS. DEAIAR~AY (Cowpt. rend. 82 1337) has described under the name of oxypyro tartaric acid the acid obtained from ethyl aceto-acetate by the action of anhydrous hydrocpanic acid and decomposition of the resulting cyanide by boiling with acids. He states that the acid so obtained is an unstable uncrystallisable syrup and that the barinm salt when boiled with excess of water is decomposed carbonic anhy-dride being evolved and barium carbonate precipitated whilst the barium salt of a different acid viz. hydroxyisobutyric acid remains in solution. H e gives the following equation for this decomposition :-OH H3C*C< C 0 .0 ‘ L l >Ba + OH2= [(CH,),C(OH).CO,],Ba + BaC03+ CO,. ir c- c 0. o From the mode of forma,tion of this acid as shown by the following H,C.CO H,C.C(OH)(CN) equations-+ HCN = I HZC. C 00 CZHG I HZC. COOC,H, an BiORRIS ON a-METHYL-HYDROXYSUCCINIC ACID ETC. 7 it is the next higher homologue of malic acid the salts of which are well-defined and crystalline thus :-HC (OH) (COOH) H,C.C(OH) (COOH) H:,C.COOH I H,C . CO OH I RIalic acid. New acid. It would therefore appear probable that such an acid would be a stable compound yielding well-defined salts. On this account a t the suggestion of Prof. Wislicenus I undertook to go over the work of Demarpy in order to obtain more conclusive evidence of the nature of this acid.Preparation of the Acid. I prepared the acid according to Demarqay's directions by heat-ing a mixture of 2 parts of pure ethyl aceto-acetate and 1 part of anhydrous hydrocyanic acid in sealed tubes for three days at 100". The tubes were then opened and the light brown contents heated on a water-bath for some time to expel the excess of hydrocyanic acid. The cyanide so obtained was then mixed with about twice its weight of rather diluce hydrochloric acid and boiled for some time in a flask connected with an inverted condenser. When the decomposition was complete the liquid was evaporated to drive off the excess of hydrochloric acid and also the alcohol formed in the reaction. The mixture of ammonium chloride and acid remaining after evapora-tion was shaken with dry ether in order to extract the acid and the ethereal solution filtered from ammonium chloride ; this was repeated until the whole of the acid was extracted; and the ethereal solution was then evaporated on a water-bath when the acid' was left as a thick brown syrup.To purify this impure product it was dissolved in water neutralised with ammonium hydrate and basic lead acetate added to precipitate the lead salt. This was collected on a filter tho-roughly washed then suspended in water and decomposed by passing a stream of sulphuretted hydrogen through the liquid. The solution of purified acid was filtered from the lead sulphide formed and con-centrated to a small bulk on a water-bath. This concentrated solu-tion was then shaken with ether several times.The syrupy acid, obtained by evaporating these ethereal solutions was still slightly colcured ; it was allowed to stand for a few days in a vacuum over sulphuric acid when it set to a crystalline mass. The completely dried mass was again dissolved in dry ether filtered from a little insoluble matter and evaporated as before. The pure crystalline acid so ob-tained was dried in a vacuum until it ceased to lose weight and was then analysed. It gave the following numbers : 8 XORRIS ON a-METHYL-HYDROXY SUCOINIC ACID ETC. I. ,1448 gram acid gave on combustion 02160 gram C02 and 11. *1990 gram gave -2975 gram CO, and -1000 gram OH2. ,0745 gram OH,. Found. Calculated for C5Hs05. I. 11. C 60 40.54 40.67 40.77 H 8 . . . . . . 8 5.M 5.72 5.58 0 6 80 54.05 I -- -148 99.99 The acid i3 very deliquescent easily soluble in water alcohol and ether andcrystallises on standing over sulphuric acid or in a vacuum, from its solution in these solvents in sta,r-like groups of needles.It melts at 108" and is decomposed at a higher temperature. Xaltsof the Acid C5EI,05. The fkee acid gives no precipitate with neutral or acid lead acetate solution but is completely precipitated by basic acetate. A solution of a neutral salt gives a white precipitate with basic acetate of lead, and also with nitrate of silver solution but with neutral lead acetate or with barium hydrate it gives no precipitate. Barium Salt.-This salt was prepared by neutralising a strong solu-tion of the acid with barium carbonate evaporating the solution to a small bulk on a water-bath and finally allowing the concentrated solution to stand over sulphuric acid until i t was quite dry.So ob-tained it is a transparent non-crystalline glassy deliquescent mass, and contailis 2 molecules of water which it loses at 150". The analysis of the perfectly dried salt gave the following results :--2128 gram salt lost on drying at 150" C. -0239 gram = 11.23 per cent. Calculated for C5H6Ba0,20H2. Found. OH 11.28 per cent. 11.23 I. *2901 gram of the 150" dried salt gave on combustion -1798 gram 11. *32M gram gave -215.3 gram COz -0640 gram 0.H2 and *2219 111. -2156 gram salt gave ~1466 gram BaC03. CO, -0547 gram OH2 and 1987 gram BaC03. gram BaC03. IT. -5093 77 ,3488 7 MORRIS ON a-METHYL-HYDROXY SUCCISIC ACID ETC.Found. Calculated for C6HBBa05. I. 11. 111. IV. 21.07 21.42 - - C5 60 21-20 H . 6 2.12 2.09 2.09 -B a . . 137 48.41 47.63 47.57 47.73 47-6 0 5 80 28.27 -- - -- -283 100.00 9 In order to test Demarqay's statement that the barium salt was decomposed on boiling with water a solution of the free acid was neutralised with barium hydrate and boiled for several hours. No decomposition however took place the solution remained perfectly clear and no gas was evolved. The solution after boiling was evapo-rated to drpness the salt dried a t 150" until it ceased to lose weight, and analysed. I. -4670 gram salt gave on combustion -2937 gram GOz -0540 gram OHz and *3268 gram BaCOy. 11. -3450 gram gave -2107 gram GOz *0722 gram OHz and .2381 gram BaC0,.111. -5480 gram salt gave a4545 gram BaS04. It gave the following numbers :-Found. Calculated for C5H6Ba0,. I. 11. 111. c 21.20 21-44 20.86 H . . . . . . 2.12 2-23 2.32 -Ba 48-41 48.63 48.00 48.Z 0 . . . . . . 28.27 I - - -The formula for the barium salt of hydroxyisobutyric acid gires the following percentage :-C . . . . . . . . . . . . . . 96 2 7.99 HI4 . . . . . . . . . . . . 14 4-08 Ba . . . . . . . . . . . . . . 137 39.95 0 s 96 27.99 343 100.01 - -The acid obtained by DemarCay probably contained a little unde-composed ethyl aceto-acetate which I found would prevent the acid from crystdllising and would also if the barium hydrate was in excess, cause the precipitation of barium carbonate on boiling the solution of barium salt.The acetate boiled with barium hydrate would saponify, as shown by Wislicenus (Liebig's Awnaleiz 186 166) according to the following equation :-CH,.C0.CIIz.COOC2H6 + Ba(OH) = RaC03 + C,H,OH + C H,. C 0. C H3 10 MORRIS ON a-METHYL-HYDROXTSUCCINIC ACID ETC. CaZcium XnZt.-This is best prepared by neutralising a solution of pure acid with calcium carbonate. It is extremely soluble in water, and is obtained as a deliquescent crystalline mass by long standing of its concentrated solution over sulphuric acid. It was only obtained crystalline by allowing a strong solution to stand for several nioiiths over sulphuric acid. It was prepared by neutralising a solution of the free acid with pure potassium hydrate. Xilver SuZt.- When silver nitrate solution is added t o a solution of the potassium salt a white bulky precipitate is formed which is soluble in hot water.On allowing tlhe hot solution to cool the salt crystallises out in plates which blacken on exposure to light. These crystals when thoroughly dried gave the following numbers on analysis :-I. -1930 gram salt gave on combustion -1145 gram GO2 -0330 gram OH2 and -1130 gram Ag. 11. -1440 gram salt gave -0850 gram C02 -0250 gram OH2 and -0845 gram Ag. PotnssiunL Salt.-This salt is also extremely deliquescent. Found. Calculated for C,I164g20 + +OH, I. I I. C5 60 16.17 H,. . 7 1.88 A g 216 58.22 05+ 88 23.72 -371 99-99 As the salt is decomposed when 16.10 16.12 1.92 1.90 58.68 58.55 heated below loo" the wat,er of crystallisation could not be directly determined.Lead SaZt.-A solution of the free acid or of the neutral salt gives no precipitate with neutral acetate of lead ; but when lead acetate is mixed with a neutral salt and then a few drops of ammonia added or better, by tlhe direct addition of basic acetate solution a dense white preci-pitate is thrown down which is not dissolved when the liquid is boiled, b u t becomes granular. The salt SO obtained consists of a basic salt, and appears to have the formula C5H6Pb05Yb0. I found it impos-sible after repeated experiments to get a pure neutral salt fit for analysis. The experiments always resulted in a more or less basic salt. Copper SaZt.-This was prepared by boiling a solution of the acid with excess of copper carbonate and filtering the solution.This salt is also very deliquescent and on leaving its solution over sulphuric acid it is obtniiied as a transparent blue glassy mass. It was also found impossible to obtain this salt neutral it being always to a greater or less extent basic MORRIS ON a-NETHTL-HYDROXYSUCCINIC ACID ETC. 11 Beduction of Acid with fuming Hydriodic Acid. About 6 grams of the acid were heated with six times its weight of fuming hydriodic acid in a sealed tube to 130-140" for six hours. When cold the tube was opened-there was a moderate pressure in the tube and smell of butyric acid-and the contents shaken with mercury to remove the free iodine which was present in large quan-tity. The nearly colourless liquid was then evaporated to a small bulk it being thought that the product of the reduction would be pyrotartaric acid which is not volatile ; the small quantity of wateiy solution was shaken with pure ether and the ethereal solution separated and evaporated on a water-bath.After evaporation only the merest traces of organic matter remained. The watery liquid from which the ether had been separated was then examined but nothing organic was found in it ; so that the conclusi'on arrived at was that the product had been dissipated in evaporation. The reaction is proba,bly ex-pressed by the following equation ; the pyrotartaric acid first formed, splitting up under the influence of hydriodic acid into either butyric or isobutyric acid and carboQic anhydride :-Either C H3 CH3 I ; CH c< -.-t . . CH CH, I I iH!I ' I .(JiH . . . . 1 iCO()iH + iHj1 = . I + OH2 + co* + 1,. COOH COOH 01' I CH . C 00 .H As the evaporations were performed in a draft cupboard there was no opportunity of hoticing the butyric acid as it was driven off. Dyy Distillation of the Acid. A portion of the acid was placed in a sniall distillation-flask con-nected with a suitable condenser and distilled €rom an oil-bath. The acid mas decomposed a t about 140" ; carbonic anhydride mixed with a little carbonic oxide was given off in abundance and an acid water 12 MORRIS ON a-METHYL-HYDROXY SUCCINIC ACID ETC. liquid distilled over. The oil-bath was kept at 200' until all evolution of gas had ceased when the flask was removed from the bath and heated over a small flame. Nothing came over below 210" but be-tween this and 215" a yellow oil distilled over.When this was all over there remained in the flask nothing but a black coaly residue. I. The Watery DistiZZate.-This was neutralised with potassium car-bonate and re-distilled. It commenced boiling below 70" and the temperature gradually rose until it reached loo" where it remained stationary. When about two-thirds of the liquid had passed over the distillation was stopped and the solution of potassium salt remaining in the flask mas poured into a dish and evaporated t'o dryness. The quantit'y of salt obtained was very small and from its reaction with sulphuric acid and alcohol appeared to be potassium acetate. The distillate was saturated with potassium carbonate which caused a small layer of liquid smelling of methylic alcohol to separate.This was separated dried and distilled ; it began to come over at 68' and fractions were collected between this and 75" 75-80" 90-99". There was however not enough of either fraction to examine. They all smelt more or less alcoholic and were all inflammable. 11. The Yellow 02.-This oil boiling between 210-215O was re-distilled ; it came over between the same limits and from its boiling point and appearance was apparently citraconic anhydride. In order t o prove this it was dissolved in water and converted into salts. At the same time some citraconic acid which Professor Wislicenus kindly gave me mas taken and also converted into salts so that the two might be compared. The following salts were prepared and analysed :-Silver Salt.-Prepared from both by addition of silver nitrate to neutral solution of acid.I n both cases a white precipitate was formed, which dissolved on boiling and crystallised from the mother-liquor in star-like clusters of needles. When dried and analysed the following results were obtained :-I. Salt from acid from distillation:-- 1 l i 3 gram salt gave -0745 gram COZ -0170 gram OH and ~0713Ag. 11. Salt from citraconic acid :--1312 gram gave *0832 CO, -0190 gram OH, and ,0797 gram Ag. Calculated f o r Found. (C5H4Agj04)2 -t OH?. I. 11. C, 120 Hi . . . . . . 10 Ag4 . . . . . . 432 0 144 706 -Lead Salt.-Prepared by 16-99 17.32 17-29 1.41 1.61 1.6'1 61.19 60.78 60.75 20.39 - -99.98 -precipitating a neutral salt with neutra MORRIS ON ~-METHPL-HYDROXk’SUCCINIC ACID ETC.13 lead acetate. with another liquor. results :-The precipitate obtained becomes granular on boiling When collected and dried it gave the following I. Salt from acid from distillation--2262 gram salt gave on combustion -1455 gram COz -0290 gram 11. Salt from citraconic acid-~2380 gram gave *1513 CO, -0288 grhm OH2 and ,1645 gram PbO. Calculated for C5H,Pb04. I. 11. C5 60 17.91 17.54 17.33 H . . . . . . 4 1-13 1.42 1.34 P b . . . . . . 207 61.79 61.84 61.40 OH, and -1507 PbO. Found. - - 0 4 64 19.10 335 99.99 - -The identity of these salts coupled with the boiling point proves the The principal reaction yellow oil to have been citraconic anhydride. wm therefore undoubtedly the following :-CH3 CH, .co’ whilst a second reaction went on which resulted in the formation of carbonic anhydride carbonic oxide acetic acid and some of the lower alcohols probably methylic ethylic and isopropylic. &emarks o n the Constitution of some of the Isomerides gf a-MetlLyl-hy droxys uccinic A c i d . Of the constitutional formulae of the five known acids of the general formula C6Hg05 very little is known. I think however that know-ing the constitution of the foregoing acid we may fix with tolerable certainty the constitution of a t least two of the previously known . - acids. Citramalic acid prepared by Curius (AnnaZen 129 153) by the action of hypochlorous acid upon cit’raconic acid and reduction of the resulting monochlorocitramalic acid with zinc and hydrochloric acid may have either of the two following formule: ON #-METHYL-HYDROXYSUCCINIC ACID ETC.CH3 CH3 I I C.OH.COOH or (11.1 dH.cooH i CH.OH.COOH CH,. COOH It is evident that the first of these formule is identical with the formula of the acid described in the preceding pages and therefore the two acids should exhibit the same properties ; but on the contrary, they are totally different citramslic acid being an uncrystallisable syrup which may be obtained by long standing in a vacuum as an amor-phons transparent mass whilst a-methylhydroxysuccinic acid is easily obtained in well-defined crystals. The salts of the two acids are also entirely different. This would seem to point t o the second of the above formulae as being the correct one f o r citramalic acid.Itamalic acid which Swarts (ZeiCsch. Chem. 1867 646) prepared by the action of hydrobromic acid upon itaconic acid and decomposition of the resulting itamonobromopyrot'artaric acid by boiling with water or alkalis may also have either of two following formule :-CH3 CH2OH 1 I I I (I) C.OH.COOH or (11) CH.COOH C H,. C 0 OH CH,.COOH But the first of these is identical both with the first of citramalic acid and also with that o f ' a-methylhydroxysuccinic acid whilst the acid itself differs from both in its propert,ies forming long deliquescent iieedles which melt a t 60-65" and giving salts different from those of the other two acids. This would again point to the second as being the correct formula. The formulm for these three acids would then be :-CH3 CH,.OH CH3 I CH.COOH I CH.OH 1 COOH I C.OH. C OOH CH2 I COOH 6-methylhydroxysuccinic acid. acid. acid. I CH. GO O H 1 CH, I and I COOH Citramalic acid or Itamalic a-Methyl111 droxysuccini

ISSN:0368-1645    

DOI:10.1039/CT8803700006

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

15 111.-Contributions to the €&tory of Pwtrefdon. Part I. By c. T. KENGZETT. IT appears t o be now well established that matters of animal and veget'able origin present no inherent tendency to pass into a state of putrefactive decomposition. In other words putrefaction is the ex-pression by which is indicated a number of specific changes induced in certain bodies by causes extraneous to the substances themselves. For the greater part of existing knowledge of this subject we are indebted to the researches of Pasteur (Conzpt. rend. 56,1189 ; Jak-esb. ,f. Chem. 1863 579) who in 1863 defined putrefaction as a fermenta-tive process induced and sustained by animal ferments of the genus Fibs-io. This definition received confirmation from Traube and Gscheidlen (DingZ.polyt. J. 222 352 ; Chesn. SOC. J . [2] 12 997), among others in lS74 and still more recently from the very interest-ing and well known experiments of ProEessor Lister. It has been subst,antiated then that just as any kind of fermenta-tion is an instance of a biological reaction manifesting itself as the result of a special force residing in organisms or in other words as " fermentation is essentially a correlative phenomenon of a vital act, beginning and ending with it,"* so also is putrefaction such another instance of a biological reaction or such another correlative plieno-menon of a vital act. Both in fermentation proper and in putrefaction there is organisation development and multiplication of the living agents. It is probable also that although certain kinds of fermentation seem to depend upon specific unvarying organisms yet in a modified form fermentattion can also be induced in the same medium by different fer-ments or organisms just as a number of hydrating agents may cause the same order of decomposition in certain chemical substances the only difference being in the specific nature of the acting agents and the resulting products or some of them.Pasteur recognises two kinds of putrefaction viz. one in which the ferment (as for instance the butyric ferment) produces the change without the aid of oxygen and that in which oxygen is also essential in promoting such change. But however this may be it is certain that mere temporary expo-sure to the air is sufficient in the vast majority of instances to intro-duce into any putrescible solution the agencies of putrefactive change.J(; See Schiitzenbei-ger's Work on Fermentation (Eing and Co.) p. 39 16 KINGZETT COSTRIBUTIOKS TO THE Under this view of .things when a putrescihle solution is exposed to the air there forms on the surface a film of bacteria mucors and mucitlines which are supposed to exclude and absorb oxygen pre-venting i t from penetrating into fhe liquid. Under the film in the liquid vibriones multiply and split up the albuminous substances into simpler products while the bacteria and the miicors excite the slow combustion of these latter into ultimate products. This is If. Pasteur’s view of the changes constituting putrefaction and it should be parti-cularly observed that vibriones cannot endure the presence of oxygen ; their function is the institution of initial change which is completed by the bact.eria and the muc0rs.X ‘‘ It follows from what has been said that contact of air is by no means necessary for the development of putrefaction.On the con-tsary if the oxygen dissolved in a putrescible liquid was not a t once removed by the action of special organisms putrefaction would not take place ; the oxygen would destroy the vibrios which would try to develop at first.”? As regards the first products of putretactive change so far as is known they resemble those or a t least are identical in some measure with those obtained by subjectiug albumino‘ids to chemical decompo-sition by hydrating agents such as dilute sulphuric acid and baryta-wat,er. This kind of decomposition has been specially studied by Schutzenberger.The ultimate products of putrefactive change would seem to result from the oxidation of the primary products and from certain ill-defined secondary influences. Under these circumstances one would naturally expect that a sub-stance allowed to undergo putrid fermentation without oxidation, would more readily undergo chemical oxidation than the original integral mass and hence that the oxygen-absorbing capacity of a sub-stance would progress increasingly with such putrefactive decomposi-tion. It thus occurred to me some time ago that advantage might be taken of this inference to compare quantitatively the prophylactic energies of various substances by determining the oxygen-absorbing capacities of organic solutions or mixtures from time to time as they passed into putrefaction and comparing these with the oxygen capacities of similar solutions protected during the same periods by so-called antiseptics.Accordingly after considerable unavoidable delay I commenced the experiments some of which I have now the honour of submitting to the Chemical Society. * Compt. rend. June 1863 and Schijtzenberger on Fermentation (King and Co.), f- Page 219 of Schutzenberger’s treatise. pp. 209-227 HISTORY OF PUTREFACTION. 17 I have made a large number of experiments of this kind but do not propose to publish the results on this occasion. It may be remarked that the investigation presents great difficulties and i t is only from a very large series of observations that any sound inference can be made.The problem would lose nearly all its difficulties if all anti-septics exercised the same kind of influence sa-j- for instance the strengthening of the combinations to break down which constitutes the function' of vibriones. But this is not the case and moreover most of the antiseptic substances tested react upon the potassic per-manganate in a chemical manner of their own. Hence the difficulties of the investigation which I am carrying on. Some of the experi-ments which I have made however seem to have an important bearing upon what Dr. Tidy describes as the " oxygen process " of water analysis and T shall only preface the description of these ex-periments by stating that I was not led to the subject by any spirit of criticism much less of hostile criticism but purely incidentally.There is a wide-spread opinion that in the putrid state a substance is capable of absorbing much more oxygen or to put i t in another way of decomposing much more potassic permanganate than in the fresh state and indeed it appears to me that the " oxygen process " of water analysis as recently described by Tidy (Chew. Soc. J., 194 80 specially) largely depends upon this assumption for he ob-serves " At anjr rate it undoubtedly furnishes us with exact informa-tion as to the relative quantities of putrescent and easily oxidisable matter and of non-putrescent or less easily oxidisable matters present in the water.'' I shall show presently that this is not clear and it appears to me that; the oxygen process is liable to mislead chemists in interpreting their results if we are to believe that the more per-nicious organic matters are those which are in a putrescent condition.For it will be seen that a water may contain a t one time organic matters in a non-putrescent condition and that when these same matters shall have become pernicious the water will absorb far less oxygen than originally ! Experiment 1 (Azcgust 14th 1879).-A dilute solution of white of egg was made filtered from membranous matter and found to contain 1.588 per cent. albumin dried a t 100" C. Of this I took 5 c.c. added 90 C.C. of distilled water then 5 C.C. of dilute sulphuric acid (1 3), and lastly 20 C.C. of a standard solution of potassic permanganate (1 C.C. = -001334 gram oxygen).The mixture was allowed to stand one hour, and the unused permanganate was then determined by estimating its equivalent of iodine with a standard solution of eodic thiosulphate in the usual way (1 C.C. = -000667 gram oxygen or f C.C. standard per-manganate). Ti1 this manner I ascertained that the albumin operated upon used VOL. XXXVII. 18 KINGZETT CONTRIBUTIONS TO THE up during the hour 6 C.C. RMnO4=*008004 gram oxygen. This then I call the " initial oxygen-absorbing capacity." 45 C.C. of the same albumin solution was now placed in a stoppered bottle of about 100 C.C. capacity and a t the periods shown below the oxygen-absorb-ing capacity was again determined upon different port'ions but under exactly iden tical conditions with the results also shown.Oxygen capacity After After After at start. 24 hours. 120 hours. 1104 hours. After After After 1176 hours. 1 4 0 hours. 1534 hours. 0 * 0 06203 1 0.0058696 0.0054694 The solution began to stink after about 150 hours' standing and henceforth i t grew worse being ultimately of a glutinous stringy con-sistence and smelling strongly of cheese having entireIy lost its purely putrefactive odour. Eqm+t?mt 2 (Augztst 27 1S79).-A pound of raw beefstea,k was digested with about 400 C.C. of water a t 50" C. for two hours filtered after cooling and allowed to stand over night. Next! morning it was already slightly pntrid t o the smell. The initial oxFgen-absorbing capacity was determined using Fi C.C. of the extract diluted with 100 C.C. of water adding 5 C.C. of 1 3 H2S04 and 20 C.C.KMn04 solution. It absorbed 0*00867l gram oxygen. 60 C.C. of the extract was now placed in a stoppered bottle of 80 C.C. capacity and another similar bottle was entirely filled with the extract, so that it was not exposed to the air. The oxygen capacities of these two solutions were then determined a t the periods and with the results here following :-0.008004 0.0086 71 0.0076038 0.00667 A. Partially filled Bottle. Initial. 24 hours. '72 hours. 144 hours. 168 hours. 0.008671 0.0089378 0.0081374 0-0081374 0*008004 0.007337 - 0-006003 0-005336 0*0050692 0.0042688 648 hours. 672 hours. 792 hours. 840 hours. 1128 hours. 1224 hours. B. Efitirelyfilled Bottle. 0-0086 71 - - - 0.0089378 0*011%39 0.0037358 0.0034684 0-0034684 - -InitiaI.24 hours. 72 hours. 144 hours. 168 hotirs. 648 hours. 672 hours. 792 hours. 840 hours. 1128 hours. 1224 hours. After 48 hours both bottles were maintained at a temperature of 49O for three hours to hasten putrefaction HISTORY OF PUTREFACTION. 19 I n A the putrefactive odour was unbearable before heating t o this temperature but curiously enough when examined after 72 hours i t smelt quite sweet. It again stank at the 14.4 hours’ examination and the odour grew worse and worse a deposit* occurring gradually and much gas being evolved on agitation. Finally the solution became quite colourless or nearly so all the colour being in the deposit. At the 1128 hours’ examination it was perfectly sweet to smell emitting only a meaty odour ; so also a t 1224 hours. B when first opened after 168 hours was found to be terribly putrid and of course after this date and up to 648 hours it was i n contact with 5 C.C.of air and after each examination the quantity of a i r was increased by 5 C.C. (the mensnPe of fluid removed). As regards appearances and odour it followed the course of A so far as observed. Experiment 3 (October 1 1879).-In this experiment I took a beef-steak in which the process of putrefaction had already commenced ; a piece of fresh herring in a similar condition and the piece of a cab-bage and made an infusion a t 40° cooled and filtered it. A small stoppered bottle was then entirely filled with a quantity of this s o h -tion and a further quantity of tbe same solution was placed in a corked bottle containing about 400 C.C.of air. The method of pro-ceeding was as in the last experiment. A. Extract in f d l Bottle. Initial oxygen 0.005 8696 - 0,0034684 0.00314824 0.00490912 0.00410872 0.004005 0*0041385 0.0041408 capacity. After 24 hours. After 336 hours. After 432 hours. After 840 hours After 1032 hours. After 1128 hours. After 1224 hours. After 1’7’76 hours. B. Extract exposed to Air from the .&a?%. Initial oxygen capacity. After 24 hours. After 336 hours. After 432 hours. 0*0058696 -0050692 0.0034684 0-00314824 0.00442888 0.0034684 After 84Q hours. After 1032 hours. On October 13 that is to say after 336 hours and when putrefaction was in full work 22.5 C.C. of the extract in Bottle A was pIaced in contact with 55 C.C. of air over mercury. After five days the volume f This deposit which occurred in dl the fluids which were allowed ho pass into putrefaction was of a silty nature and in no way interfered with the determina-tion of the oxygen-capacities since by agitation of the fluids it could be equally disseminated throughout the mass.This was proved by making (in the majority of instances) duplicate experiments which always yielded the same results. c 20 KINGZETT CONTRIBUTIOKS TO THE of gas in tube measured 59 C.C. A little caustic potash was now intro-duced and this absorbed 4 C.C. of gas leaving therefore the original volume unabsorbed. I do not attach much importance to this experi-ment; i t was quite of a preliminary nature and perhaps after all, oxygen had been absorbed from the air and an equal volume of other gas (hydrogen or nitrogen) unabsorbable by potash set free.Be this, however as it may it would seem from the comparative experiments, A and B that this one instance of putrefaction in no way depended upon the contact of air per se and a a y indeed proceed independently of it. The putzefaction in A and B proceeded rapidly the solutions keep-ing their red colour which even seemed to intensify for Bome time. On examination at the 336 hours both were horrible to smell and had largely deposited ; both evolved much gas on agitation. The appear-ance was much the same after 432 hours. Later on the red colour of the solution disappeared the deposit simultaneously increasing ; the odour too changed from the recent putrefactive to a stale butyric odour.After 1032 hours A had not lost this latter smell altogether, but B had and cmitted only the smell of some compound ammonia. Z y e T i m e n t 4 (November 3 1879).-Four or five pounds of raw lean beef was minced and macerated in pure water a t about 40". The extract contained 3 per cent. (?) solid matter dry a t 100". A. 200 C.C. of this cxtract was placed in a stoppered bottle of about '250 C.C. capacity. B. 200 C.C. of the same extracf was placed in a stoppered bottle of this exact capacity. C. 50 was exposed to 47.5 C.C. of air over mercurr. Initial oxygen capacity of After Aftrr Af tcr After Aftw 5 c c. 96 hours. 192 hours. 278 hours. 37'4 hours. 926 hours. A . moo73959 -006942 -0064614 *00631455 ~006942 -0064355% C. .0073959 -00643552 B.*0073059 - - -006942 -007743~ -0068m6 Volume of gas in air-tube = 44.5 C.C. -0071289 A and B both began to stink after 48 hours from start and both grew increasingly worse and made a considerable whitish deposit. Now postponing for the moment the consideration of these results in regard to the phenomenon of putrefaction they seem to reflect as I have already said upon a probable source of error in the rjxygen pro-cess of water analysis. During the discussion upon Dr. Tidj 's valuable paper I pointed out that pernianganate of potash according to his own * After this examiiiation a quantity of this extract was placed in a bottle of its precise measure and a t the 926 hours' stage the oxygen-capncity as found to bc -0075'712 HISTORY OF PUTREFACTIO~ 21 results (this Journal 1879 1 78) seems to have little influence upon gelatin in a fresh state; and since gelatin is one of a class of bodies liable to putrefactive changes and hence liable to give rise to perni-cious products it appeared to me that the oxygen process was liable to overlook certain albumino'ids which was a serious objection.I t now appears from the experiments which I have described that the oxygen process might not only pass a water containing such an albuminoi'd as good but it might also pass a water containing pernicious products, since it is possible to obtain such 8r sdutiou which will exhibit a much smaller capacity for oxygen than the original fresh solution from which it is derived. So far as these experiments go they confirm the fact (which has been more than once disputed*) that putrefaction can begin and proceed in the absence of oxygen (that is as such) and in common with some researches of Nenckit they confirm the history of putrid fermentation as laid down by Pasteur.I n some of the experiments the putrescible solution showed in the next earlier stages a tendency to undergo slightly greater oxidation thau at the start ; it may be because up to this time the agencies at work consisted mainly of a hydrating character ; but as this proceeded and the quantity of available oxygen from without increased other agencies initiated amd carried on the oxidising influence constituting the second act of ordinary putrefaction. It would seem also that in soine of the experiments the agencies at work had the power of obtain-ing oxygen from within the mixtures for the quantity of oxygen available as air w m in certain instances no0 sufficient to account for the decrease in oxygon-absorbing capacity if we regard that decrease as due to interim oxidation.The presence of free oxygen doubtless assists the later changes. Finally it will be seen that in the history of putrefaction there comes a time when the activity of the agencieB at work greatly diminishes and finally almost ceases. No doubt this is due not merely to the using up of material ready to undergo putrefactive changes but also to the poisonous influence of the putrefactive pro-ducts when present in certain amount upon the agenta themselves. This has been well shown by Cmce-Calvert and Thornson Nencki, and others. Such a result is comparable with another observed in the process of alcoholic fermentation. So soon a3 the alcohol reaches a certain * For instance by Gtunniug in J. pr. Chem. [2] 19 266. t See paper by Nencki ibid. [19] 337-358; Abstracted in Chem. SOC. J., $ See a pamphlet by W. Thornson " On the Principal Agencies of Putrefaction Manchester (Palmer and Howe) 1875. November 1879 page 953. and Decomposition. 22 WRIGHT AND MENKE ON NAXGANESE DIOXIDE. amount fermenation ceases because the yeast cells are rendered inac-tive by the alcohol.* The ground-work however is not sufficient t o admit of much theorising and had it not been for the interest which the results origi-nated as to the oxygen process of water analysis I should not have submitted the experiments in their pbesent incomplete form

ISSN:0368-1645    

DOI:10.1039/CT8803700015

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

22 WRIGHT AND MENKE ON NAXGANESE DIOXIDE. IV.-ATotes on Naizganese Dioxide. By C. R. ALDER WRIGHT D.Sc. (Lond.) Lecturer on Chemistry in St. illIary’s Hospital Medical School; and A. E. MEXKE Daniell’s Scholar King’s College. § 1. Introductoyg. THE experiments described in this paper are essezltiallly a continuation of some observations detailed in the “ Second Report on some Points in Chemical Dynamics,’’ presented to the Society by one of us and Mr. A. P. Luff (this Journal 1878 1 504) in which it was shown that pure hydrated maxiganese dioxide is not produced by two of the processes nsnally described as giving rise to that substance viz., acting on potassium permanganate with nitric acid and treatment of manganese chloride with sodium hypobromite ; the products con-tained considerably less “ available oxygen ” than corresponds with the formula Mn02.These results have since been extended and con-firmed by Gorgeu (Cow@. re72d. 88 796) who has observed that the products obtained by oxidising protoxide or carbonate of man-ganese either heated or in the cold by treating manganate or per-manganate of potassium with nitric acid by exposing permanganic acid to spontaneous decomposition and by electrolysing dilute solu-tions of manganese salts uniformly contain less oxygen than corre-ponds to the dioxide. Various specimens of these products showed on titration amounts of total oxygen of from 35.2 to 36.5 per 100 parts of anhydrous substance MnO containing 36.8 parts hence the deficiency in the “ available oxygen ” amounted to from 0.3 to 1% out of 18.4 or from 2% to ik of the quantity of available oxygen in Mn02.These products were stable in the air or in contact with distilled * This was shown by a large number of experiments made by Tliudichuxn in con-junction with the author but unfortunately the manuscript was mislaid and so thc experiments hare not been published JJ-RIGHT AND MENlGC ON MANGANESE DIOXIDE. 28 water suffering no change even after lengthened periods of time ; on treating them with potash they neutralised and combined with amounw varying from 1 to 14 per cent. i e . they acted like feeble acids as Gorgeu had previously (in 1862) found manganese dioxide to be capable of doing (Aim. Chim. Plzys. [S] 66 153) forming salts of the general formula 5Mn02.X20 where X is a monad.On the other hand Gorgeu has also found that the manganese dioxide produced by heating manganese nitrate to about 160° shows little or no deficieney in oxygen and that it does not combine with potash exhibiting in these respects and in its physical properties a close resemblance to the natural minerals polinnite and pyrolusite. S. U. Pickering also has recently found that by dissolving manp-nese superoxides in large bulks of strong hydrochloric acid and diluting with water substances are precipitated which exhibit a con-siderable deficiency in available oxygen as compared with MnO (this Journal 1879 !€'ro.~~s. 654). During the last twelve months having had occasion to prepare a quantity of manganese dioxide for the purpose of examining the character of the curvd surfaces rcpresenting the mutual relations of time temperature and amount of deoxidation by various reducing agents we have examined afresh the product of the action of nitric acid 011 potassium permwanate and have been surprised to find that even when the quantity of nitrie acid present is very large relatively to the manganese the substance precipitated invariably contains a not inconsiderable amount of potassium combined so firmly as not to be in the slightest degree washed out by continued boiling with water.This circumstance bas led us to examine the substances regarded as more or less pure manganese dioxide formed artificially in various ways, with a view to seeing whether potassium is similarly retained by these substances when prepared in presence of potassium compounds.Our experiments indicate that whenever potassium is present in a solu-tion from which a manganese superoxide is precipitated a larger or smaller quantity is invariably retained in Combination in the precipi-tate. 'The same remarks appear as far as our experiments have gone, to be equally true as regards calcium and probably many other metals; indeed in the case of calcium the tendency of manganese dioxide to carry down foreign metals in combination appears to be superior to its power of uniting similarly with potassium for man-ganese dioxide precipitated from a solution conta,ining a little calcium, and several times as much potassium will frequently carry d,own more calcium than potassium. The action of nitric acid on pernianganate of potassium may be regarded from several points of view thus the action may be supposed t o consist in the setting free of permanganic acid which graduall 24 WRIGHT AND MENKE ON MANGANESE DIOXIDE.decomposes evolving oxygen and depositing manganese dioxide or manganese nitrate may be supposed to be formed and to react on the undecomposed permanganate in accordance with the well-known reac-tions (as applied to the sulphate or chloride) on which Gujard founded his volumetric method of manganese determinatioii :-3MnX2 + 2KMn04 + 2Hz0 = 5Mn0 + 2KX + 4HX. I n either case the retention of potassium in the precipitate seems to indicate that manganese dioxide (the acide manganeux of Gorgeu) is sufficiently acid in its character to displace nitric acid from nitrates.It is however difficult to see why the precipitate thrown down should exhibit a deficiency in oxygen for being formed in presence of excess of permanganate it should contain all tlhe manganese as dioxide, Gorgeu having stated in 1862 that when a manganous salt is added to excess of permanganate the precipitate has the coniposition of hydrated MnO, although a " manganite of manganese," 5Mn02Mn0 (or Mn6011, exhibiting a deficiency of one-sixth of the available oxygen in MnO?) is obtained when the permanganate is added to excess of the manganese salt (AWL Chirn. Pliys. [3] 66,153). Guyard subsequently stated whilst describing his volumetric method (Bzcll. SOC. ClLirn. 1864 1 SS) that the temperature of the solution influences the nature of tthe precipitate.At SO" a precipitate of hydrated Mn02 is thrown down ; at lower tem-peratures oxides exhibiting a deficiency of oxygen are obtained corre-sponding with the formulae 4Mn0.Mn207 and 5MnO.MnzO7 (or Mn6011. and Mn7Ol2) manganese dioxide prepared in this way beiug viewed by Guyard as a basic permanganate of manganese 3Mn0.Mnz07 and these compounds as yet more basic analogous substances. Guyard represents the precipitate as containing the elements of the hydrate MnO2.HZO ; Rammelsberg however (Ber. 1875 233) represents the substance formed by acting on potassium permanganate solution with strong sulphuric acid and then adding water as 3MnO?.2H2O,* and this formula is also applied by Morawski and Sting1 t,o the substance examined by them some months ago obtained by adding manganous chloride to potassium permangsnnte solution and drying over sulphuric acid ( J .pr. Chem [Z] 18 78). No one of these observerat appears to have noticed the presence of * Rammelsberg gives the percentages Mn = 55.56 0 = 16'16 caIculated for the iormula 3Mn02 2H10 and Mn = 55.48 0 = 15.63 as those found thus exhibiting a slight deficiency in oxygen to the amount of - 32 p r t doubtless, however the manganese was over-estimated a5 potash is carried down tlie preci-pitate. Vide s 4. j- Since the majority of our experimenis were mode a paper has appeared by J. Volhard (Annaleiz September 1879 198 318) in which tlie author states that the manganese dioxide precipitate obtained by adding poi assinm permanganate to 16.16 -15'63 - 1 - 16.1 WRIGHT AND MENKE ON JIAT\'GAI?\'ESE DIOXIDE.25 considerable amounts of potassium in these products (several per cents. of K,O). Morawski and Sting1 indicate in one part of their paper that the product obtained by the action of potassium permanganate on manganese chloride is free from potassium for they give the analytical numbers 56.0 per cent. of Mn and 1.33 of H (calculated for 3Mn0.2H20 Mn = 55.56 H = 1.34). Subsequently however they state that traces of potassium are apparently carried down with the precipitate as the filtrate contains ratlier more hydrochloric acid and rather less potassium than corresponds to the above equation; they indicate the amount however as being a t most only a few tenths per cent. inasmuch as they state that on treating this precipitate with potas-sium carbonate solution an amount of pota,ssiurn was withdrawn from ?he solution t o the extent of 9-17 and 9.23 per cent.the compound hjln,KH,O, (or 8Mn02.Kz0.3H20) being produced ; the calculated xmuunt for the tmnsformation of 3Mu02.2H20 into this compound is 9-87 per cent. This ultimate compound Mn4KH3010 they state is formed whenever potassium permanganate acts in a neutral solution (originally) upon various organic substances siich as potassium thio-cyanate alcohol glycerin oxalic acid &c. On repeating their experi-ments as described below we have obtained entirely different results, the alleged definite substance Mn4KH,010 not having been produced in any one instance examined. § 2. 2CZccngnnese Dioxide prepared from Potassium Perrriaiigannte by Nitric Acid A concentrated solution of potassium permanganate (filtered warm through glass wool) was acidulated with about one-fifth of its bulk of strong nitric acid so that the resulting liquid contained a t least 25 per cent.by weight of HNO, and kept on the water-bath for some time until most but by no means all of the permanganate was destroyed ; the heavy black precipitate was washed several times by decantation and tinally on a glass wool pnmp-filter until every trace of acid was absent from the filtrate. The product was then dried over sulphuric acid for several days; when dry to the touch the clots were pulverised by light pressure and the whole left over sulphuric acid for some months. Portions taken out after 1 3 and 5 months' standing over sulphuric acid were analysed with the following results.The available oxjgen was determined by boiling with hydrochloric acid receiving the evolved chlorine in potassium iodide solution and titrating with an excess of sodium thiosulphate going back with a decinormal iodine solution, manganese sulphate contains combined potassium unless the solution is strongly acidu-lated with nitric acid in which case not more than traces are present in the precipi-tate. Our result,s do not agree with his (vide infra) in this latter respect (wide $7) 2 t i WRIGHT AND MENKE ON MAXGANESE DIOXIDE. against which the thiosulphate was checked. In some cases the substance was boiled with acid ferrous sulphate in excess and the excess determined by ;t standard potassiam diuhromate solution, against which the ferrous sulphate was checked.Numerous experi-ments showed perfect identity between the average results of the two processes when perfectly pure dichromate and eiLrefully standardised solutions are employed (the iodine being standardised with specially prepared pure arsenic trioxide) ; only a trace of iodine was generally liberated on distilling the hydrochloric acid used into potassium iodide in a blank experiment; this amount was always subtracted (with some samples of acid and iodide this correction is very appre-ciable). The water expelled oa ignition was determined in two ways firstly by heating in a current of dry air and collecting the ex-pelled water in a CxC1 ttuhe; secondly by igniting weighed amounts and determining the loss of weight and the available oxygen in the residue.Subtracting this latter from the original available oxygen the oxygen expelled was ktiown ; and subtracting this from the loss on igniting, the water expelled was known. The average results by the two pro-cesses coincided perfectly. It was found that practically the whole of the water present was expelled on ignition the residue left on igniting several grams in a current of dry air in a large platinum boat never giving more than a very few milligrams of additional moisture on withdrawing the boat whilst still hot adding to its contents several times their weight of recently fusSd not completely cooled potassium dichrornate and heating again to fusion of the whole mass. Minute quantities of water were however thus obtained,* apparently indi-cating that on ignition a portion of the potash present became con-verted into KOH.This was corroborated by the circumstance that on treating with water the ignited substance (not fused with potassium dichromate) sensible quantities of potash were dissolved out forming a highly alkaline solution ; more than half of the potmsium present, however was usually still retained in a form of combination incapable of being dissolved out by boiling water. After 1 Mmth. Mean. Available oxygen. . 15.78 15.89 15.84 Water - - 5.60 Manganese monoxide and potash . . - - 78.67 100.11 * Morawski and Sting1 state (Zoc. cit. supra) that the same amount of water is expelled from a hydrated manganese dioxide containing potash by simple ignition as by fusion with potassium dichromate.Our experiments shorn that this result is only approximately true ; the residue left on ignition in a current of dry air unti %*RIGHT Ah'D MENKE ON MAKCASESE DIOXIDE. 27 After 3 Months. Mean. Available oxygen 15.80 15.86 15.96 16.03 - 15-91 Water . . . . . . . . . . . . 5.31 5.14 5.01 4.93 4.88 5.05 Manganese monoxide and potash 79-24 79.04 78.85 78.72 - 78-96; -99.92 After 5 Months. Available oxygen 15.93 16.02 16.05 16.16 16.04 Manganese monoxide and Water (by difference) 4.52 100.00 potash 79.54 79.34 - - 79.44 From these numbers it is evident that a very slight loss of water but no loss of oxygen attended the prolonged drying over sulphuric acid ; the experiments with other samples of hydrated manganese dioxide described below confirm these results indicating that no loss of oxygen whatever takes place either during the first drying of a moist precipi-tate over sulphuric acid or subsequently but that a continual pro-gressive loss of water takes place on long standing over sulphuric acid ; when a certain amount of water is thus lost (varying with the mode of preparation) the rate of loss becomes very small barely appreciable amounts being lost in several weeks.The amounts of manganese monoxide and potash severally present i n the sample dried f o r three months were carefully determined in several ways viz. heating with hydrochloric acid (or pure sulphuric acid) evaporation to expel the greatsr part of the excess of acid treat-ing with pure yellow ammonium sulphide (specially prepared and free from alkalis) and convert'ing the manganese sulphide into MnS04, by dissolving in pure hydrochloric acid evaporating to dryness with pure sulphuric acid and gently igniting a t a dull red heat ; the filtrate was evaporated to dryness in a platinum vessel and the residue ignited with sulphuric acid and the potash weighed as K,SO,.In some cases the weight thus obtained was checked by conversion into potas-siuni platinochloride; it was found that if a glass or porcelain evaporating vessel were used the potassium sulphate obtained was contaminated with lime silica alumina and alkalis derived from the ressel ; the same vessels hardly parted with a trace of corroded matter 110 further traces of moisture were yielded to a CaCla tube invariably yielded a little inoisture on adding to the still hot substance fused not quite cooled potassium di-chromate and heating again to fusion of the mass i.e.of the potassium dichromate. The amount of adhtional moisture thus obtained never exceeded 0.3 per cent. how-erer and averaged only about 0.2 per cent. with the substances examined 28 WRIGHT AND MEXE ON MANGANESE DIOXIDE. on evaporating down in them even strong hydrochloric acid solution. Another method tried was solution in hydrochloric acid evaporation to dryness heating finally to fusion in a crucible with a perforated lid tllrough which a stream of hydrochloric acid gas was passed in, weighing the residual mixed chlorides and then separating them by ammonium sulphide as before.It was found very difficult to avoid loss of manganese by volatilisation of the cliloride in t,his way ; direct experiments showed that MnClz can be readily sublimed id a current of hydrochioric acid gas on ignition for some short time and that the escaping gases when passed into water give an acid solution from which a perceptible residue of manganese chloride can be obtained on evaporation to dryness on the water-bath. A third method consisted of prolonged ignition in a boat in a current of hydrogen. At first potash sublimed in the fore part of the tube and for some hours the substance gradually lost weight even after the manganese was wholly reduced t o green oxide; but after some 12 or 14 hours it constant weight was attained and the residual MnO although usually just alkaline to moist test-paper contained only just discernible traces of potassium.* I n this way the following numbers were obtained :-MnO.K20. 7551 sulphates) { 75.51 as chlorides) 75.18 3-42 { ;:;; By sulphuric acid method (weighsd as By hydrochloric acid method (weighed By ignition in hrdrogen 75.37 -75-24 -75.20 -L_ Average 75-33 3.46 The sum of the MnO and K,O thus found is 78.79 whilst the amount of “manganese monoxide and potash” found as above described as being left on ignition (after subtracting the “ avai!able oxygen” also left) was 78.96 whence it would seem that 0.17 per cent. of water was retained by the ignited substance in the form of KOH. This quantity sensibly accords with the amounts of moisture obtained as above described on reheating the ignited substance with * It was found that the green manganese monoxide thus obtained when free from potash did not spontaneously oxidise in the air ; but if a minute quantity of potash were present the substance usually took up oxygen on standing in the air, becoming covered with a brown or black film the spontaneous absorption of oxygcn noticed by Wright and Luff (this Journal 1878 1 526) was doubtless due to the 13resence of small quantities of potash in the specimens observed to undergo this change which were at the time noticed to behave differently from pure maugauese nioiioxide prciared by long-continued ignition in hydrogen FRIGHT AND MESKE ON AlhKGhXESE DIOXIDE.29 a large excess of potassium dichromate; in three experiments the amounts of moisture thus olitnined were 0.19 0.17 and 0.30 p e ~ cent.; average 0.22 ; so that the total quantity of water present was 3-05. + 0.22 = 5.27 per cent. The percentages of MnO K,O 0 and H20 thus finally found correspond prett’y closely with those required for the formula-29Mn0.02,.K,0.8H,0. Calculated. Found. MnO 75.45 75.33 0 15.83 15.91 K,O 3.45 3.46 H,O 5.27 5.2 7 100~00 99.97 Prom this it is evident firstly that the water in this specimen of hydrated manganese dioxide corresponded neither with Rammels-berg’s formula 3MnO2.2H,O nor with Gnyard’s MnO2.N,0 but represented a much smaller amount of hydration which moreover, appeared to be not constant becoming slightly but sensibly rediiced on further long standing over sulphuric acid ; and secondly that the “ available oxygen ” present showed a deficiency as compared with that in Mn02 of about 2 parts in 29 or between 6 and 7 per cent.22.53 - 21-19 22-53 = 6-26 per cent. the available oxygen (more exactly present per 100 of MnO being x 100 in the sample examined, 7.533 16 71 and - x 100 in MnO, or respectively 21.12 and 22.53). Another specimen of manganene dioxide was prepared in the same way. Either from a difference of temperature during the precipita-tion or from some other unexplained cause however a consider-ably larger quantity of water was retained after drying over sulphuric acid for two months. By analysis as before the following average percentages were obtained indicating a composition pretty close to that of the preceding sample saving as regards the combined water agreeing fairly with the formula 34Mn0.032.K20.22H20 :-Calculated.Found (average). MnO 70.67 i0.68 0 14.99 14.91 2.80 KZO u (-3 H,O (expelled on ignition) . . 11*.59 11-56 100~00 99.95 9.C” - -30 WRIGHT AND MENKE ON MANGANESE DIOXIDE. The deficiency of oxygen in this specimen (as compared with that in MnO,) is almost identical with that in the previous one; for the oxygen per 100 of &In0 = - 70.68 = 6-39 per cent. is the deficiency in oxygen in this specimen 6.26 being that found in the formep one. The amount of water retained after two months is however more khan double that found in the former specimen. As in that case this amount was not constant for on further standing over sulphuric acid more water was lost; thns, after six weeks more (making fifteen weeks in all) the second speci-men contained only 9.54 per cent.of water. In order to see whether the deficiency in oxygen in these samples was possibly caused by spontaneous decomposition during drying a third specimen was prepared by adding to a hot nearly boiling solu-tion of permanganate twice its volume of concentrated nitric acid so that the total liquid contained upwards of 70 per cent. of HNO ; in a few minutes a large portion of the permanganate was decomposed but by no means all. The whole was then largely diluted with water the precipitate washed by decantation several times finally drained on a pump-filter and examined without drying in order to avoid the possi-bility of any loss of oxygen during the drying.An unknown quan-tity of the moist substance mas heated with hydrochloric acid and the evolved chlorine titratecl; the residual chlorides were evaporated down with sul'phuric acid to convert them into sulphates and the potash separated from the manqanese by ammonium sulphide as above described. In this way numbers were finally obtained for the weights of MnO K20 and 0 present yielding the following percentages relatively to their sum corresponding with the formula 43Mn0. ~,,,K,O. MnO 80.62 80.46 0 16.90 17.04 KzO 2-48 2.50 100~00 100~00 14'91 x 100 = 21.09 whence 22e.53 - 21.09 22.53 Caleulated. Found. -The deficiency in oxygen in this specimen was therefore almost identical with that found with the previous two specimens for the oxygen per 100 MnO was x 100 = 21.18 whence the defi-22.53 - 21'18 = 5.99 per cent.the ciency as compared with Mn02 was other two specimens giving respectively 6.26 and 6.39 per cent. deficiency. The amount of potassium retained in combination in this specimen however is perceptibly smaller thaii the quantity found in 17.04 80 4b 22.5 WRIGHT AND JIEXKE ON MASGANESE DIOXIDE. 31 Time in hours Oxygen lost (per 100 of original substance) . . Water lost at 210'. . Water expelled from re-sidue on ignition Total water --either of the other two samples doubtless owing to the effect of the larger proportion of nitric acid used. Some observations mere made on the loss of moisture and oxygen expel-ienced by the first two samples of snbstance on heating in n slow current of dry purified air for various periods to loo" and also to 210" (in a bath of naphthalene vapour).The loss of oxygen was determined by carefully titrating the substance before and after the exposure the Ioss of weight being also determined; by subtracting from the loss of weight the loss of oxygen found by the difference between the titrations (reckoned in each case per 100 parts of the sub-stance originally employed) the amoumt of water expelled TTW known. In some instances this amount was checked by igniting the dried sub-stance in a stream of dry air and collecting the expelled vater in a, CaC12 tube. The following numbers weFe obtained at 210" as the averages of several determinations in each instance :-3 0 -25 4 '33 0 -8'7 5 '20 Sample 11 I Sample I (dried 3 months omr sulphuric acid.) 8 0 '29 4 -03 -.- -47 0.03 9 15 - Nil (a gain of 0.02 was actually de-termined).0.23 I 0 25 *43 9 -9 -92 9.96 I I 1.77 30 0 -10 I ~~ __________~ ~ At 100" the following numbers were obtained as averages :-Sample 11. I Sample I. Time in hours Oxygeii lost (per 100 of original substanee) . -.--Water lo& a t 100". . Water expelled from re-sidue on ignit,ion . --Total water The total water capable of expulsion by heat deduced from the From these numbers it is evident that whilst the loss of oxyger previous analyses was 5.05 for Sample I and 11.56 for Sample 11 32 WRIGHT AND 31ENKE ON MAKGANESE DIOXIDE.experienced a t 100" is no greater than the experirnental errors of analysis at 210" a slight but perceptible evolution of oxygen appears to take place. The amounts of water retained at the ordinary tem-perature a t 100" and at 200° also appear to be very variable the substance retaining the most a t any one temperature also retaining the most a t any other temperature. Some specimens (such as those described in the 2nd Report) appear to become practically anhydrous at 200" in a few hours whilst the above specimens retained frcm 0.57 to 1.77 per cent. S. U. Pickering states (Zoc. cit. s y r a ) that from 3 to 6 per cent. of water was retained by the samples examined by him after drjing a t ZOO". 8 3. Mawganese Dioxide from Manganese Superchloride by precipitation with Water.I n order tlo see if potassium is carried down by manganese when precipitated from a solution of superchloride by copious addition of water a quantity of the substance above described prepared from potassium permanganate by the action of nitric acid (con-taining MnO = 70.68 K,O = 3-80 0 = 14.91 HEO = 11.56) was dissolved in about 50 parts of concentrated hydrochloric acici and the solution filtered through glass wool. To. one half of the so-lution a quantity of concentrated solution of potassium nitrate was added (the amount of salt added being about treble the weight of the dioxide used) and the whole then thrown into water; after skand-ing 24 hours the precipitate was washed by decantation and finally on the pump-filter. The other half was precipitated by addit,ion of water only.The substances obtained were examined whilst still wet by boilirg with hydrochloric acid to determine the oxygen and separating the manganese and potassium from the resulting chlorides as above describcd. The following percentages were obtained, calculated on the sums of the K20 MnO and 0 found corresponding respectively with the formula 49Mn0.04s.2K20 and 113&h0.01m.K20. Ma 0. 0. E20. Sample prepared with Found . . . . . . 78.38 17-32 4.29 potassium nitrate { Calculated . . 78-45 17.31 4-24! Sample prepared with- Found. . . . . . 81-.55 17-50 0.95 out {Calculated . . 81.49 17.55 0-96 As indicated by the experiments of Pickering each of these specimens contained less oxygen than corresponds t o 1\9nO2 the oxygen per 100 of MnO being respectively 22.11 and 21.46 corresponding to de-ficiencies in oxpgen of 1.86 and 4.75 per cent.respectively; thes WRIGHT AXD MENKE ON MANGANESE DIOXIDE. 33 numbers moreover are in harmony with the experiments subsequently described ($ 7) the deficiency in oxygen being least in the sample containing the most potash. The potassium present' per 100 of MnO is greater in the first samplc than in the original snbstance but less in the second example :-2-80 Original substance K,O per 100 MnO = 7m x 100 -= 2.96 Sample prepared with KNO ,, , without ,, 4.29 x 100 = 5.47 78.38 Oeg5 x 100 = 1.16 81.54 whence it results that decomposition of the added potassium nitrate (or of the potassium chloride formed from it by the action of the strong hydrochloric acid) must have been produced by the manganese dioxide a t the moment of its formation from the superchloride and the potassium carried down in combination with the manganese and oxygen.I n the second sample the effect of the large quantity of acid has diminished the amount of potassiiim retained by the manganese, just as was observed with nitric acid previously (9 2). It would thus seem that the distribution of the potassium in solution between the mineral acid and the precipitated manganese dioxide is regulated, amongst other things by the relative masses of acid and mariganese present (possibly also it depends on the state of dilution tem-perature &c.) , § 4. Manganese Dioxide pyepared by the Action of Xulphzcric Acid on Potassium Permaizgannte.A warm concentrated solution of potassium permanganate was treated with its own bulk of pure snlphuric acid cautiously dropped in and the boiling hot fluid largely diluted with water. The precipi-tate which subsided gave the following numbers after drying for some days over sulphuric acid until a,pparently perfectly dry approximately bearing out Guyard's statement that the hjdrnted manganese dioxide formed by precipitation contains MnO,.H,O ; a notable amount of potash was however also present the numbers agreeing with the formula 23MnOz.KZ0.22H2O :-Calculated. Found. MnO 65.57 65.51 0 14-77 14-89 K 2 0 . . 3.77 3.69 H2O 15.89 15.91 (by difference) 100'00 100~00 VOL. XXXVII. 34 WRIGHT AND JIENKE ON MASGANESE DIOXIDE. No deficiency of oxygen a t all was here perceptible the oxygen per 100 MnO found rather exceeding that due to MnO (through experi-14-89 niental errors doubtless); for - x 100 = 22.73 whilst MnO, 65.51 requires 22.53.On standing over sulphuric acid a t the ordinary temperature a loss of water was noticed without loss of oxygen ; after another fortnight the sample contained MnO = 67-74 0 = 15.25 K,O = 390 H,O = 13.11 corresponding with the formula 23MnOL.K20.17H,0 and in-dicating therefore a loss of nearly one-fourth of the water. The oxygen per 100 MnO was as before tho same as that due to Mn02, within the limits of experimental error; for ~ x 100 = 22.51 (MnO requires 22~~53). After yet another fortnight the percentage of water was 12.77 indieating that the rate of loss of water had become greatly reduced.From these numbers and those obtained with the specimens above described prepared from potassium perinanganate by means of nitric acid (9 2) it would seem that the hydrated manganese dioxide thrown down by precipitation a t first approximates to MnO,.H,O and that the water is gradually lost over sulphuric acid but not completely a cci*tain amount (depending probably on the physical state and ap-parently on the quantity of K,O present vide §§ G and 7 ) being retained with considerable firmness even a t temperatures up to 210'. 15.25 67.74 § 5. Manganese Dioxide prepared by the Action of Sulp7LzLr Dioxide on Potassium Perma? ganicte. A stream of washed sulphur dioxide was led into a cold solution of potassium permanganate which was kept in large cxoess throughout: the brown precipitate was washed thoroughly by decantation and on tile pump-filter and then yielded the following numbers (analysed as above described whilst still wet) agreeing with the formula-1 4~MnO.O,,.K2O :-Calculated.Found. MnO 77.66 77.74 0 . . . . . . . . . . 15.00 14.9 7 KzO 5.34 7.29 100~00 €00-00 A very large deficiency in oxygen is here noticeable the oxygen per 100 of B h O being 2 x 100 = 19.26 whence the deficiency rela- 14-97 77.7 IT RIGHT AND MESKE ON MANGANESE DIOXIDE. 35 9 6. Manganese DioaXe preyared by the Action of Alcohol or Glyceriw on Yotuss L'um Permanganate. According to Morawski and Sting1 (loc. cit. supra) the brown pre-cipitate formed when glycerin or alcohol is added to permanganate solution and the whole gently warmed contains the elements of the compound 8MnO2.K20.3H20 after drying at 100".Our experiments do not confirm this. A nearly saturated cold solution of permanga-nate was added to glycerin dissolved in 6 or 8 parts of water and the whole gently warmed (temperature ultimately about SO-35'7. After a few minutes the whole of the permanganate was reduced the brownish-black muddy precipitate was thoroughly washed and ana-lysed as above described whilst still wet ; two different samples A and B gave the following numbers the numbers in the column headed C being obtained with a third specimen in the preparation of which alcohol was substituted for glycerin :-A. B. C* Available oxygen 12.99 11.41 14.37 MnO '78.56 82-36 70.78 K,O 8.45 6.23 14.85 100~00 100.00 100~00 These numbers correspond respectively with the approximate formula? 12MnO.O,.KZO ; 35Mn0.02,.2K20 ; and 20Mr~O.0~~.3K2.0, differing widely from one another and from Morawski and Stingl's formula (which becomes 8M11O2.KzO when reckoned on the anhydrous substance) not only in the presence of different quantities of potassium relatively to the manganese but also in the manganese being asso-ciated with very much smaller quantities of oxygen than correspond to MnO,. After drying over sulphuric acid and finally at 100" for six hours these three substances contained respectively 9.77 10.21 and 9.57 per cent. of water expelled on ignition (collecbed in a CaC12 tube), thus indicating the retention at 100" of much larger quantities of water than were observed with the substances prepared by heating permanganate solution with nitric acid (9 2).Morawski and Stingl's formula requires 6-44 per cent. of water. According to Morawski and Stingl,. the same compound, 8Mn0,.K,0.3H20 is produced when hydrated manganese dioxide is heated with potassium hydrate or carbonate solution well washed and dried a t 100". We treated with a large excess of dilute caustic potash solution the subst ince described in the next section prepared by actkg with hot dilute manganese suiphate solution on excess of hot potas-sium permangaziate solution the whole being kept in boiling water €or D 36 WRIGHT AND 'MENKE ON MANGANESE DIOXIDE. 12 hours after thorough washing and drying over sulphuric acid for a few days till apparently quite dry the following numbers were ob-tained agreeing with the formula 21 Mn02.4K20.19H20 (approxi-mating to Gorgeu's formuh SMn02X20), Calculated.Found. MnO 58.59 58.51 0 13.20 13.24 K20 14.77 14.87 H20 13.44 13-33 (by differeuce). 100.00 100-09 After drying a t 100" for several hours this substance retained 9.73 per cent. of water capable of expulsion on ignition ; whence it would seem a s indicated also by the numbers obtained with the substances prepared by acting on permangannte wit5 alcohol and glycerin that the presence of much potash diminishes the ease with which water is expelled ; experiments corroborative of this are also described in the next section. S 7. LWanganese Dioxide prepared by the Action of Potassium Perrnnnga-nnate on Manganese Xulphate.In order to test the correctness of Giirgeu's and Guyard's statements (supra) as to the amount of oxygen relatively to the manganese preci-pitated under different conditions four experiments were made with the same solutions of pure manganese sulphate and potassium perman-ganate each solution containing about 5 per cent. of the dissolved salt. In the first and second experiments the manganese sulphate solution was slowly poured into a considerable excess of permanganate the solu-tions being both a t 130-85" in the first case and cooled down (after dissolving the salts with the aid of heat) to the ordinary temperature in the second case. The third and fourth experiments were analogous respectively to t h e first and second as regards temperature but dif-fered in that the permanganate solution was poured into a considerable excess of manganese sulphate.The precipitates were well washed by decantation and finally on the pump-filter and examined whilst still wet an unknown weight being boiled with hydrochloric acid to deter-mine the oxygen and the manganese and potassium determined in the resulting mixed chloride solution. The following percentages were deduced from the sums of the weights of MnO 0 and K,O thus found corresponding respectively with the approximate formulae :-No. I . . 15Mn02.K?0. , 2 . . . . . . '72A1n0.0,,.3K20. , 3 . . G5Mn0.062.2K,0. , 4 . . . . 66Mn0.06,.K,0 KRIGHT AXD MENKIE OX NBNGASESE DIOXIDE. 37 3 h O . 0. &!O. {Found 76-32 17.M 6-62 Calculated 76.12 17-16 6.72 i8-24 li.39 4.37 , 2{F:und Calculated 78.28 17.40 4.32 Fourid 79-62 17-14 3-24 Calculated 79-64 lie12 3.24 81.21 17.17 1.62 , 4 {Found Calculated 81.19 17.18 1-63 I n the case of sample No.1 the deficiency in oxygen is so small as to be almost within the limits of experimental error; the other samples especially the two last show perceptibly larger amounts of deficiency :-Oxygen per 100 Deficiency compared with of Mn.0. Mn&. 17.06 0-1 8 0.3 I 22.22 - - 1'7.39 78.24 1 *(30 rn 22.53 -1-38 81-19 t L 35 No. 1 i6.32 x 100 = 22.35 'md = 0.81 per cent. . . . . x 100 = 22.53 - 1-38 9, 17.14 x 100 = 21.53 ~ - 4.44 ,, , 2 ) 3 ) ) 4 l7*I7 x 100 = 21.15 - = G.17 ,, It would thus seem that whilst the formation of such substances as the Mn5011 and other oxides yet more deficient in oxygen described by Guyard and Gorgeu did not take place in these experiments yet the statement of Guyard that precipitation in the cold yields a substance more deficient in oxygen than one similarly prepared a t about 80" is perfectly correct specimens Nos.'L and 4 (prepared cold) containing re~pect~ively less oxjgen relatively to the MnO present than Nos. 1 and 3 (prepared a t 8 0 - 4 3 " ) . It is also noteworthy that the amount of combined potassium in these four specimens varies inversely with the deficiency in oxygen in other words the more potassium oxide is pre-sent combined with MnO, the less MnO is carried down similarly combined. As might be anticipated too more MnO is thus carried down when the MnS04 is in excess than when the permanga-nate is.By using more dilute solutions of manganese sulphate and pelaman-gauate keeping the latter in excess and precipitating hot (at about 80-90-)) it is possible to obtain a precipitate containing every trace of the manganese present as MnO (associated with potash). Thus experiment No. 1 was repeated employing solutions of one-tenth the strength (0 5 per cent. of each salt present). The precipitate obtaine 38 WRIGHT AND MENKE ON MANGANESE DIOXIDE. after drying over sulphuric acid for a few clays till apparently quite dry gave numbers agreeing with the formula 1 1MnO?.Kz0.7H20, and exhibited no deficiency in oxygen :-Calculated. Found (average). MnO 66.35 65-85 0 14-95 14.94 K,O 8.00 8.26 HzO 10.70 10.95 (by difference).100~00 100-00 Oxygen per lOC MnO = 14'94 - x 100 = 22.69 MnO requiring 65.85 22-53. It is noteworthy that in this case the amount of potash present relatively to the manganese is greater than was the case with speci-men No. 1 which exhibited a small deficiency in oxygen ; the water present in this specimen was considerably below that required for the formula MnOz.HZO but was close t o that required for 3&In0.2Hz0 : 2 H O - 36 3Mn0 213 t,he latter gives the ratio - - - = 16.90 per cent. whilst 10-95 - there was found - - 16-63 per cent. So far as this particular 65.89 specimen is concerned therefore the view of Rammelsberg that hydrated manganese dioxide is 3Mn02.2H20 would appear to be con-firmed ; but the previously described experiments indicate that the composition is actually variable between the limits Mn02.H20 and something roughly approaching the anhydrous state according to the length of time that the specimen is allowed to stay over sulphuric acid which is further confirmed by the following numbers represent-ing the percentages of water expelled on ignition and collected in a CaClz tube from the specimens Nos.1 2 3 and 4 just described each dried over sulphuric acid for oue week and three weeks Nos. 1 and 2 mere coppery cdoured when first examined Nos. 3 and 4 nearly black. Percentage of Water collectecl. Dried over H,SOA 1 week. Dried 3 weeks. No. 1 13.39 13.22 . 3 . . . . . . . . 8-28 7.50 4 9.41 9.08 , 2 16-53 12-90 As previously indicated 9 6 t'he specimens containing most potash parted with water least rapidly WRIGHT AXD JIENKE ON NANGANESE DIOXIDE 39 It is possible to obtain complete precipitation of manganese as MnOz in the cold by adding zinc sulphate t o the permangannte solu-tion and then gradually pouring in the manganese salt SO that the permanganate is always in excess.Determinations made thus with known quantities of manganese furnished amounts of precipitate con-taining available oxygen equal to 37.5 to 37.65 per 100 MnO in the mangar.ese salt used. Since the precipitate is formed in virtue of the reaction-3MnX + 2KMn04 + 2H20 = 5MnOZ + KzX + 2H2X, three-fifths of the manganese in the precipitate comes from the man-ganese salt and two-fifths from the permanganate wherefore the available oxygen due to the manganese was equal to.0.6 x 37.5 to 0.6 x 37-65 or 22.50 to 22.59 per 100 MnO MnO requiring 22.53 (vide 9 9). Since these experiments were made a paper by Volhard has ap-peared (Annulen 198 318) in which the author states that pm manganese dioxide containing a t most traces of potash is obtainable by dissolving 10 grams of manganese sulphate in half a litre of water, adding 100 C.C. of nitric acid sp. gr. 1.2 heating on the water-bath, adding excess of permanganate keeping on the water-bath for an hour and washing the precipitate at first with water acidulated with nitric acid and by decantation and finally on the filter and drying on bibulous paper &c, The foregoing experiments however mould indicate that a greater amount of potassium is carried down in combination with the mangz-nese dioxide than would appear from Volhard’s statements.On pre-paring some of the prcjduct in exact accordance with his directiom, thoroughly washing and drying for a few days over sulphuric acid till apparently quite dry to the touch the following numbers were ob-tained indicated by the formula 30Mn02.K,0.1 7H20 :-Calculated. Found (average). MnO 70.76 $0.65 0 15.95 i 6 m K20 3.12 307 H20 10-17 10.28 100*00 100-00 -Ratio of MnO to available oxygen 100 to 22-62. Calculated for MnO 100 to 22.53. The amount of potash in this sample relatively t o the manganesc was however notably less than was the case with either the last-described substance (prepared from 0.5 per cent.solutions of mangn 40 WRIGHT AND MEXKE OX IIAR’GAJSESE DIOXIDE. nese sulphate and potassium permanganate) or the previously described substance No. 1 (prepared from 5 per cent. solutions), doubtless owing to the influence of the added nitric acid; so that Volhard’s observation that the amount of potsash carried down is lessened by adding nitric acid is (as also indicated by the previously described experiments §$ 2 and 3) perfectly correct the only error being in the actual amount of potash carried down which is evidently much more than mere traces. 9 8. Nanganese Superoxide prepured by the Action of Air a n d Cuustic Potash on Manganese Chloride. Manganese chloride (prepared by boiling permanganate of potas-sium with h”ydroch1oric acid and evaporation nearly to dryness to expel the excess of acid) was dissolved in some 20 parts of water and excess of caustic potash added the whole was placed in a flask with a wash-bottle cork and tube attached so that by attaching an aspi-rator t o the shorter tube a continuous current of air could be sucked through the whole and the manganese oxidised in accordance with Weldon’s well known method.After some 30 hours’ treatment a large portion of the manganese was peroxidised ; the brown precipi-tate after thorough washing contained (reckoned as anhydrous) :-Available oxygen 10.24 Manganese oxide MnO 87.53 K20 2 2 5 100~00 A little lime derived from impurity in the caustic potash was also present. These numbers are represented by the formula 58BiIn0.0,,.K20.The great deficiency in oxygen is doubtless due to the action of the air not having been prolonged sufficiently and being allowed t o take place at the ordinary temperature. A considerable quantity of potash was permanently combined with the manganese notwithstanding. 8 9. Manganese Dioxide precipitated by Byomiize iiz presence of Potassium Acetake. It has long been known that manganese dioxide precipitated from an acetate solution by bromine or chlorine is apt to carry down alkalis with it increasing its weight so much so that in various analytical text-books (e.g. Fresenius’s) it is stated that the precipitate must be dissolved in acid and reprecipitated as carbonate before ignition t o convert it into Mn,04. In order to see how much potassium could be carried down in presence of a very large amount of potassium salts TRIGHT AND MESI(E O S 31A4?\'GBN;ESE DIOXIDE.41 some potassium permanganate was boiled with hydrochloric acid and the solution treated with a quantity of potassium acetate in quantity representing some 15-20 times as much potassium as there was pre-sent manganese (to avoid presence of lime the potassium acetate was made from redistilled acetic acid and calcined cream of tartar precipi-tated from pure nitre by tartaric acid). The whole was heated on the water-bath and a considerable excess of bromine dissolved in strong potassium bromide solution added so that altogether the potassium present was probably about 25 times the weight of manganese in solu-tion. After standing on the water-bath for about' an hour the pre-cipitate was washed by decantation and on the pump-filter and annlysed wet as above described with the following results in per-centages of the sum of the K20 MnO and 0 found corresponding nearly with the formula 501\hO2.7KZO.Calculated. Found. MnO 70.89 71.03 0 15.97 1594 K,O 13-14 13.03 100*00 200-00 15.94 Oxygen per 100 MnO = 7,,,03 ~ x 100 = 22.44. Calculated for MnO = 22.53. After standing over sulphuric acid for a week this substance con-tained 14.18 per cent. of water corresponding with 50Mn02.7K,0.4GH20. After three weeks the quantity was diminished to 8.90 per cent. num-bers being obtained agreeing with the formula 50Mn02.7K,0.27H20. Calculated. Found. MnO 64-61 64.73 0 14.56 14.50 K,O 11.99 11.87 H,O 8.84 8.90 100*00 1@0*00 14.50 Oxygen per 100MnO = ___ 64.73 x 100 = 22.40.NnO2 requires = 22-53. It is hence manifest that the sample lost water on drying over sul-phuric acid to considerably below the amount due to t,he formula 3Mn02.2K,0 like most of the other samples examined ; further tha 42 WRIGHT AND MENKE ON ;MANGANESE DIOXIDE. loss of oxygen accompanied the desiccation ; and thirdly that the de-ficiency in oxygen compared with MnO was but; small viz. a t most = 0.58 per cent. 22-53 Other samples prepared in a similar way but in presence of much smrlller quantities of potassium salts exhibited much larger de-ficiencies in available oxygen the deficiency being apparently increased if the precipitation took place a t temperatures considerably below 90-100".The largest deiiciencynoticed was in a specimen which gave (after standing over scllphuric acid for a few days till dry to the touch) numbers agreeing with the formula 64Mn0.O,,.K20.63H20, exhibiting a deficiency of upwards of 14 per cent. conjoined with but a small percentage of potash. § 10 Volumetric Deternzim$ion of Xangmese. It has been shown by Kessler (Zeits. Anal. Chem. 1879 18 Part I) that by slowly adding manganese solution to hot bromine-water con-taining zinc cbloride and sodium acetate and finally boiling the whole of the manganese can be thrown down a s MnO (associated with zinc) wliilst Pat'tinson has simultaneously found (this Journal 1879, 1 365) that ferric chloride or zinc chloride will produce the same result when added to the manganese solution along with bromine-water calcium carbonate being finally added to the hoti liquid.We have repeated the experiments of these observers both in their original forms and with modibaltions and can corroborate their accuracy, with certain reservations in the latter case. Substances contsiriing known a,mounts of manganese were dissolved to known volumes and eqnal aliquot parts taken and examined in vaiious ways-(a) by exactly following Kessler's directions ; (6) using Pattinson's originnl method ernployiiig bromine-water and ferric chloride ; (c) employing Pattinson's modified method (Zoc. cit. 371) employing zinc sulphate in lieu of ferric chloride ; ( d ) using a simple modificatioiz of this last process viz. adding to the somewhat acid hob solution a considerable excess of bromine-water and then freshly precipitated zinc carbonate.In all four cases results were obtained (by washing and titrating the precipitates with €errous sulphate and dichromate or permanganate) agreeing closely with each other and with the amount of manganese actually present the differences between the results of the four pro-cesses not being greater than the differences between the results of repetitions by the same process. To obtiin the best results we found it desirable to boil the liquid and precipitate after digesting on the water-bath for a few minutes (the precipitat'ion being effected at a temperature as near 100" as possible) so as to expel all free bromine WRIGHT AND JIEX'KE ON MANGANESE DIOXIDE 43 as directed by Kessler.The precipitates obtained thus by methods a G and d contained the whole of the manganese present as Mn02 (of course associated with zinc oxide &c.). When the ferric chloride method was used however the filtrate almost invariably contained permanganate in solution whereas this never occurred with any of the processes in which zinc was employed. We found that the best method of estimating the manganese thus contained was the comparison of its tint with an equal bulk of water coloured with measured quantities of deuinormal permanganate solution ; this compa ison is not readily made unless the whole o r almost the whole of the free bromine has been boiled off owing to the alteration in colour produced by the bromine. Reduction by nlcohol &c.invariably gave a precipitate containing less available oxygen than corresponded to tbc manganese contained therein (vide $ 6) and hence led to an under estimation of the total manganese present. We obtained good results when the solutions were so diluted that about 150 to 200 C.C. of total fluid (in-cluding bromine-water) were present for every 0.1 gram of MnOz precipitated using a quantity of zinc sulphate or ferric chloride con-taining from 1.5 to 2 parts of metal for 1 part of Mn02 and sufficient bromine-water to make the supernatant fluid after precipitation moderately dark amber or sherry colour in short an excess of two or three times the amount of bromine actually requisite for oxidation of the manganese. All these processes however are open to the objection that they require the use of bromine (or bleaching powder) and are apt to im-pregnate the air of the laboratory disagreeably with the vapoars thereof unless worked in a fume chamber the following modification of Guy ard's permanganate process we found to give good results and to be less troublesome as regards manipulation than any of the others.The solution which should not contain much free acid especially if hydrochloric acid is present is diluted with water until it contains no more than equivalent to 0.1 gram MnO in 150 or 200 C.C. ; zinc sul-phate to the extent of some 10 parts of crystallised salt per 1 of MnO, to be precipitated is then added to weak (about 0.5 per cent.) solution of permanganate the quantity of which is somewhat more than that required to precipitate the manganese salt ; this latter is then slowly poured into the permanganate (not vice uersd) without heating and with shaking or stirring.In a few minutes most of the supernatant pink fluid can be poured off through a glass-wool filter on to which the precipitate is brought and washed finally the precipitate is titrated with ferrous sulphate and dichromde or permanganate ; three-fifths of the manganese dioxide thus found is due to the manga-nese in the solution examined. To minimise sources of error the dichromate or permanganate solution should be standardised in th 44 WRIGHT AND RIESRli ON I\IhNGANESE DIOXIDE. same way with a manganese solution of known strength ; if the per-manganate solution be hot too high results are apt to be obtained through partial decomposition of the excess of permanganabe either by heating alone or more probably by the action of traces of volatile organic matter in the water used for washing dust &c.; whilst if the zinc sulphate be omitted and the precipitation effected in the cold, too low results are obtained owing to the formation of a precipi-tate containing a deficiency of oxygen (§ 7). The following numbers obtained with equal bulks (50 c.c.) of one and the same manganese solution illustrate the nature of the results obtainable similar values being obtained in numerous other analogous experiments ; the numbers are given in cubic centimeters of quintinormal ferrous solu-tion (+ x 28 gram Fe in the ferrous state per litre) oxidised by the manganese dioxide precipitabed.1. Precipitated by adding to boiting solution of permanganate 32.8 C.C. 2. Precipitated by adding to coZd solution of permanganate without ZnS04 32.25 ,, 3. Precipitated by adding to coZd solution of perrnanganate with ZnS04 3‘2.65 ,, 4. Precipitated hot by Pattinson’s original pro-cess (ferric chloride and calcium car-bonate) after correction for a small quan-tity of permanganate formed. . 32.55 ,, 5. Precipitated hot by Pattinson’s modified process (zinc sulphate and calcium car-bonate) 32.6 ,, 6. Precipitated hot by adding bromine-water and zinc carbonate 32.S5 ,, 7. Precipitated hot b3 adding bromine- water and 20 parts sodium acetate to 1 of MiiO, formed 32.1 ,, 8. Precipitated by exactly following Kessler’s directions (bromine-water sodium acetate, and zinc chloride used).. 32.6 ,, Evidently the boiling permanganate method (1) gives slightly too high a value through decomposition of the excess of permanganate, whilst the cold permanganate without ZnS04 (a) and the sodium acetate without ZnSOa (7) methods precipitate substances deficient ir, oxygen as shown above ($8 7 and 9). The other methods give practi-cally identical results ; of t>hese No. 3 involves the least trouble and inconvenience WRIGHT AXD MENKE OX JSAKGASESE DIOXIDE. 45 tj 11. Manganese Dioxide prepared f r o m Hanganese Nitrate by Heat. Pure manganese carbonate was dissolved in just sufficient dilute nitric acid and the solution evaporated to a syrup which was then heated to 160-165" in an air-bath for some hours.Precisely as described by Gorgeu a pyrolusite-like substance was thus obtained after treatment of the product with boiling water and thorough wash-ing when dried in the air or over sulphuric acid for a few days a little moisture was retained a portion only of which was expelled on heating to 210" for several hours. The following numbers were ob-tained the manganese being determined ( a ) by weighing as MnSOJ, ( b ) by igniting and determining the " available oxygen" left in the residue and (c) by reduction in hydrogen at a red heat. (a) (6) (c) Mean. MnO . . 80.74 80.45 80.63 - 80.61 0 (by iodine process). . . . 18.19 18-23 18.39 - 18.23 H,O by ignition and col-lection in a CaC1 tube. . 1.32 1.25 1-02 0.96 1.14 The oxygen On heating 5t vapour-bath) in of 0.34 per cent.-99-98 x 100 = 22.61. 18.23 par 100 of MnO found is 8~,.6~ MnO requires 22.53. portion of this Substance to 210" (in a naphthalene a current of dry air for f'our hours a loss of weight only was observed which did not increase even after nine hours. The residue thus left when ignited gave off visible quan-tities of water the amount collected in a CaCI tube being 0.62 per cent. No loss of oxygen whatever occurred even in nine hours not oily was the loss of weighl a trifle uiader that due to the average water found (0.34 + 0.62 = 0.96 against 1-14 per cent.) instead of being above it a s would be the case were oxygen expelled as well as water, but further the residue left gave on titration 18.25 of oxygen per 100 of original substance or precisely the same amount as that found before drying.According to Gorgeu pure manganese dioxide is produced even if other metallic nitrates (e.g. potassium calcism &c. nitrates) are present in the manganese nitrate employed. I n order to see whether this substance is wholly free from potassium, a mixture of about equal weights of manganese nitrate and potassium nitrate was dissolved in water evaporated to a thick syrup on the water-bath and heated to 160" for several hours. The pyrolusite-lik 46 WRIGHT AND MENKE OX NAXGASESE DIOSIDE. substance obtained was crushed and well washed with hot water and then contained (after drying in the air)-MnO. KZO. 0. H20 (by difference). 79.57 1-64 17-67 1.32 = 100 Oxygen per 100 MnO - 22-27 The potash present however was apparently due to the difficulty of thoroughly washing out all soluble potassium compounds for another specimen similarly prepared but ground up fine in a mortar gave, after well washing and drying in the air the following numbers :-MnO.K,O. 0. H20 (by diaerence). 79-88 0.37 17.97 1.78 = 100 Oxygen per 100 MnO = 22.50 Whilst on grinding up in an qgate mortar and boiling with water for sonic time perceptible amounts of potash salts were dissolved out and the residue left contained only traces of potash. Hence Giirgeu’s statements as t o the non-formation of a manganese dioxide contain-ing potash by heating the nitrate of manganese in presence OE potassium nitrate are evidently quite correct notwithstanding their 4 priori im-probability in view of the decomposition of potassium nitrate and other salts by hydrated manganese dioxide; and as stated by him the substance obtained exhibits but little if any deficiency in oxygen.A notable distinction between this substance and the other bodies examined also was the following on shaking up with concentrated coZd sulphuric acid and allowirg to stand for twenty-four hours the substance subsided leaving a colouriess supernatant fluid (manganic sulphat,e was however formed if the liquid were strongly heated). Every other specimen described in this paper gave a pink violet-pink, or violet supernatant fluid (manganic sulphate presumably) on treat-ment with cold acid and clearing by subsidence. 0 12. ConclusWns. From the preceding experiments which are partially repetitions of those of Pickering Kessler Pattinson Gorgeu Guyard and others, the following conclusions may be drawn :-(1.) 1S;Ianganese dioxide prepared by precipitation processes and freed from extraneous water is (leaving out of sight metallic oxides carried down with it) a hydrate &InO2.H,O ; but it is impossible to keep this hydrate in dry air as it loses water readily at the ordinary temperature.The rate a t which the water is lost appears to be very variable being the more rapid cceteris paribus the less combined potash is present; no definite hydrate of any kind sfable in dry air appears to exist ‘as every specimen examined continually lost water over sulphuric acid VRIGHT AND MENKE ON MANGANESE DIOXIDE.47 even after several months when the amount of water present was ieduced to about 5 per cent. ; although one or two specimens mere obtained which lost water only slowly when they attained a composit:on approximating to 3MnOp.2H20 the great majority lost much more water before the rate of further loss became small. (2.) Neither at the ordinary temperature a t IOO" nor a t 210" does the hydrated substance become anhydrous even after the lapee of many months in the first case and hours in the two subsequent cases ; the amount of water thus quasi-permanently retained is very variable. (3.) Neither at the ordinary temperature nor at loo" is the expul-sion of water accompanied by any material loss of oxygen if indeed any a t all is lost at 210" however a slow regular loss of oxygen takes place on continued heating (the substance prepared by heating the nitrate does not lose oxygen thus).(4.) Hydrated manganese dioxide if prepared in presence of potas-sium salts invariably carries down with it in combination more or less potash the amount thus fixed varies with the circumstances; in presence of much free acid (nitric hydrochloric) the amount is les-sened whilst on boiling with caustic potash or digesting a t loo" it appears to become a maximum corresponding nearly with the ratio described by Gorgeu viz 5Mn02.Ki0. In presence of certain potassium salts e.g. acetate nitrate &c. the precipitate appears to decompose a portion of the salt setting free the associated acid to a greater or a less extent. (5.) When tbe precipitation takes place under such conditions that not much potash (or other equivalent metallic oxide) can be carried down by the manganese dioxide a greater or lees deficiency in oxygen (compared with Mn02) is noticeable in the precipitate ; i.e.manganese itself is carried down a s MnO in the precipitate. This is especially noticeable when the substance is formed by adding potassium permanga-iiate to excess of manganese sulphate or when the precipitate is produced by the action of a large quantity of nitric acid on potassium permanganate or by diluting with water a very acid solution of man-ganese superchloride (Piekering). Heating the solution appears to diminish the deficiency of oxygen in the precipitate (Guyard). (6.) By operating in particular ways the deficiency of oxygen in this precipitate may be reduced to very small limits or nil; for example adding manganese sulphate t o excess of potassium perman-ganate solution the liquids being not too concentrated and a t a tern-perature near 100" (Guyard) ; adding bromine to a hot solution of a manganese salt in presence of potassium acetate and other potassiirm salts jointly containing a very large quantity of potassium relatively to the manganese present or iu presence of an acetate and a zinc sal 43 WRIGHT ASD MEXKE ON MANGANESE DIOXIDE.(Kessler) or of ferric chloride and calcium carbonate (Pattinson) or of zinc carbonate. (7.) Acting on potassium permanganate solution with reducing agents such as sulphur dioxide alcohol or glycerin gives rise to a precipitate containing much less available oxygen than corresponds to the manganese present ; potash is carried down in combinatioii with the precipitate but the composition of the latter is very variable.In no case has any substance been obtained of the composition (after drying at 100') Mn4KH,01 (or 81\iIn0,K20.3H,0) said by Morawski and Stingl to be always produced under such circumstances ; nor is this substance formed by heating precipitated manganese dioxide (containing a little potash) with caustic potash solution for some hours, as stated by them; the product thus obtained approximated to the composition ascribed years ago by Gorgeu viz. 5M302.Kz0 (reckoned on the anhydrous substance). (8.) The statements of Gorgeu as to the formation of sensibly pure MnO by heating manganese nitrate to 160° and the freedom of the pyrolusite-like product from combined potassium even though potas-sium nitrate is present in large quantity are perfectly correct.(9.) The statements of Volhard as to the formation of pure hydrated manganese dioxide by precipitating manganese sulphate with excess of permangarlate in presence of nitric acid in the way described by him, are only partially correct inasmuch as the product contains several per cents. of combined potash instead of traces only at most as stated by him ; but the manganese and available oxygen in the product are sensibly in the ratio required for Mn02. (10.) The statements of Morawski and Stingl. as to the complete expulsion of combined water in hydrated manganese dioxide containing potash by direct ignition are only partially correct ; almost the whole is thus expelled but a little is retained apparently through the formation of KOH which can be dissolved out of the ignited product by water.(11.) Long continued ignition in hydrogen removes all or nearly all, of t,he potash present in a hydrated manganese dioxide containing potash leaving behind sensibly pure MnO of a much brighter green colour than that formed by the similar reduction of manganese dioxide free from potash. (12.) Manganese monoxide retaining a little potash (prepared by reducing dioxide containing potash in hydrogen but not completely expelling all the potash present) frequently oxidises spontaneously in tbe ordinary moist air whereas when free from potash the monoxide does not appear so t o oxidise. (13.) Manganese chloride is sensibly volatile in a stream of HC1 gas at a red heat FRED. D. 1 3 ~ 0 ~ 1 7 ~ OX FRACTIOSAL DISTILLATION. 4 9 (14.) Several different processes for estimating manganese volu-metrically have been compared and the work of Pattinson and Kessler confirmed ; sundry new modifications OF conihinztions of previouslj-known processes have been examined and found to give satisfactory results the one suggested as most convenient and exact being precipi-tation by addition i ~ the coZd of the manganese solution to be deter-mined to excess of permanganate solution containing zinc sulphate, collection on a glass wool filter and titration with acid ferrous sulphate and permanganate or dichromate solution preferabl~ stnndardised in the same way with a manganese solntion of known strength

ISSN:0368-1645    

DOI:10.1039/CT8803700022

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

FRED. D. 1 3 ~ 0 ~ 1 7 ~ OX FRACTIOSAL DISTILLATION. 4 9 V.-The Comnpnratixe Value of Uifereizt Xethods of Fyactiorznl Distillation. By FREDERICK D. BROWN E.Sc. WHERE fractional distillation is carried out on a large scale carious forms of appratus of a somewhat complicated character are generally employed ; though differing much in detail they are all clesigued to subject tlie mixed vapours to one or both of two well defined processes, which for the purposes of this paper may be termed respectively L V I L S ~ ~ ~ and cooZi?rg. In the process of washing the mixed vapours issuing from the still are made to pass through sevei-a1 layers of liquid obtained by their own partial condensation they are thus washed by these successive layers and it is supposed that the vapour of the liquid of highest boiling point is partially removed by this process which results there-fore in a distillate containing more of the liquid of lo\T-er boiling point than would be obtained by simple distillation.There is a t first sight however no reason t o suppose that a mixture of vapours should be materially altered in composition by a liquid having about the same composition and the same temperature as itself. It would appear that the first step iii the construction of these forms of apparatus resulted from an attempt to utilise the latent heat! of the vapour given off by a weak spirit to distil R stronger one ; the latent heat of the vapour of this second spirit might then be used t o distil a third and so on thus effecting a series of distillations in the same apparatus with the same fuel.I f this series of distillations actually took place that is to say if the ~apours rking from the still really voi. XXXTIl. E 5 '3 FRED. D. BROTT" THE COJIPARBTIVE VALUE OF condensed in the first layer of liquid thus causing that liquid to boil and emit vapour which condensed in the second layer causing that to boil in its turn the advantages of the process would be undeniable ; but since apparently the vapours only pass through the layers of liquid, and may therefore rcmnin nearly unaltered the real valne of this method of distillation can only be determined experimentally. In the process of c007i72y the mixed vaponrs are partially condensed, cither by allowing radiation to talic place o r by passing them through a coil kept at a given temperature ; the liquid of highest boiling point suffers of course the most condensation and runs back into the still, :t better distillate being t h u s obtained.Now a possible explanation of' the silccess of the fimt process i s that the successive layers of liquid, by obstructing the passage of the vnpour @re it more time to cool by radiation and that thus the t w o processes are really one and the same. With a \-iew t9 leawing whether these two processes of zoasliiug and cooZivg really differ in their effects I liave made the experiments now to be described. Two distillations were firbt made one with a form of apparatus advo-cated by Linneman (AwnccZen 160 Ins) Le Be1 and Henninger (Conyf. w?id. 79 480) and others designed to wash the 1-apours and termed ;;t dephlegmator the other merely with a long ascending tube suitable for partially condensing them.The liquids employed were carbon clisulphide and benzene selected for reasons given in a former paper (this Journal 1879 547). The composition of the several fractions of the distillates was determined by observing their densities in the manner described in the same paper. All the percentages given below represent the number of molecules of CS in a hundred moleeules of the mixture assuming of course that the weights of the molecu~es of CS2 and C,H are to one another as 76 is to 78. Distillation with De23?ilegrncttor.-547.5 grams of a mixture having a density of 1.07672 a t 19*SOo and containing therefore 62.54 per cent. of C& were clist,illed from a flask having a capacity of about a litre, and fitted with a dephlegmator having the form and dimensions shown in Fig.1; the distillate waq collected in the receiver described in the before-mentioned paper (this receiver was used also in all the subse. quent distillations). The barometric pressure during the distillation was 7513.7 min. (corrected and reduced to 0"). The following table gives tbe details of the disiAlation : DIFFEItEST XETHODS OF FRACTIONAL DISTILLATION. 5 1 Percentage of CSd. 8'7 *71 a . 5 1 81 +29 78.62 7 2 -113 66.04 49 -00 34.39 14 *30 2 *84 0 *15 --Nuinher of fraction. 1 . 11. . 111. IV . v VI . VII VIII . 19 . x XI. Telvpcrature of distillation. 0 0 61 -5-52-5 52 -5-54 -0 54 '0 -55'0 55 *0-56 ' 5 56 '5-60 '0 60 '0-63 *O ci3 -0-70 -0 70 -0-75 '0 '75 '0-75 *5 78 '5-80 '0 50 .o-80.1 %'eight of fraction.-52.34 105 *41 63 -18 81 -15 2-8 '37 51 -70 35 -31 22.4% 27 *6S 30.69 31 *05 Density at 19 *SO". 1 '19562 1 *17857 1 -16230 1 '14912 1.11878 1 '09150 1 '02430 0 '9'7525 0.916'77 0 '88733 0 '88072 Distillutioiz with Long Tube.-The tube used in this experiment i m s that shown in Fig. 2. Two thermometers were placed in this tube, one (B) at the bottom the other ( G ) at the top ; i t was thus possible to observe any change which might take place in the temperature of FIG. 2. lG the mixed vapours as they passed up the tube. 499.3 grams of a mixture having a density of 1.07660 at 19-80' and containing tliere-fore 62-51 per cent.of CS were distilled; the barometric pressure during the distillation was 771.3 mm. The results are given in the following ta,ble : 52 FRED. D. BROWN THE COXK'ARATIVE VALUE OF Number O f fraction. I . i . IT a . 111. . . . . . . IT v . . . . . * . VI . . . . . . . TI1 ,. VIII . . . IX . . . . . . . x . . . . . . . . Tenipcrntnre of distillation. 0. 0 0 50 *5 -51 *5 51 -5 -52 '2: 5 2 '23-53 *5 53 *5 -55.5 55 *5 -58 '0 58.0 -61'0 61.0 -71.5 71.5 -77 - 5 77 -5 -79 9 ' 7 79.7 -80'0 Weight Of fraction. Density n t 19 .80° 41 .OO 65 .04 7 3 . 5 6 66.69 51 *77 31 '46 51 *81 31 -00 25.10 28 *82 1 .l!)528 1 * 19047 1 'lS6Oa 1 -15631 1 .13432 1 .lo869 1.03583 0.94180 0 0 88158 Percent age of cs,.--87 -65 86 *07 84'01 80.11 75 *54 69.97 52 -14 23.27 5 -36 0 -50 I n order to compare the results of these two distilhtions they must be reduced to some common form ; for although the original mixtures contained the same amount of CS2 in both cases tho weights of the corresponding fractions were not equivalent. The distillations were therefore expressxl graphically (see diagram) in the following simple manner :-Let W = the total weight distilled wl w2 wj . . . = the weights of the several fractions ; then - loo lL'l ___ loo 7'2 he. will represent the weights of the fractions expressed in hundrecltlis of the total weight W. Now let yl yI? y3 . .. = the percentages of CS in the serernl fractions ; during the distillation of a fraction the vapour passing over varies i n composition its mean value being represented by the composition of the whole fraction = y. If we suppose that the vaponr has this mean composition when exactly half the fraction has passed over then when the accumulated distillate equals 1 -the vapoiir passing over will contain yl per cent. of CS2 ; when the dis-tillate equals ____ + ' 1 r2 the vapour passing over will contain w ' w 50 1 0 w - - I 100zcl 50 l.L' W W I00 (?/+ + 9 ' 3 . ) 50 71'7 - + I_- - x3 the w W y2 per cent. of CS,; when it equals vapoiir will coz:tnin y3 per cent. of CS2 and so on. W e have therefore the necessary data for determining the points of a curve expressing the variation in compositioii of the vapour as the distillate passes over or in other words tlic curve gives u s the com-position of each hundredth of the clistillute.I have inc*ludecl in tlic diagram tlie ciirvcs representing the two first distilhi ions recorded in the paiier pre\kms!J- referred to (thi I r n 490 80 70 60 9 4w 30 f20 70 0 I0 20 3u 60 70 80 700 Harrison & Sans Lith. 3 Martins Lane.w. UIFFEREXT METHODS OF FRACTIOXAL DISTILLATIOS. 5s Journal 1879 Trans. 547)) which were made with mixtures containing practically the same amounts of CS2 viz. 61.95 per cent. and 61-76 per cent. The following table gives t'he values of tel y1 ; x2 yz &c., for each of the four distillations a representing the distillation from the retort b that; from the flask with T-piece c that with dephleg-mator d that with long cooling tubc :-a.2. 2 . 9 14.3 28.9 43 .o 55 -9 65.4 72.8 78 .9 84-9 89 *7 Y3 *3 95 -8 Ye --82 .9 81 '2 78.8 75.4 70 ' 3 64 '1 xi -4 4.5 -8 30 .6 13 *1 5 - 3 0 -9 2. 3 . 6 14 -7 29.7 42 .9 53.1 62 .0 69 -9 76.6 83 .0 83 *7 93 .7 98.1 6. Y. 2. 4.8 19 .8 34 *6 47.8 57 *8 63 *1 73 *3 78 '8 83.4 88% 94 -5 -c. d. 2. 4 . 1 14 *8 28.8 48 '8 54 -7 63 '0 71.4 79.7 85 -3 90 -7 --Y. 87 *7 86.1 84.0 80.1 7 5 . 5 70.0 52 .I 23.3 5 -4 0 *5 ---On examining the four curves obtained by joining each series of points of which the above numbers are the co-ordinates we see, Srstly that the T-piece although generally employed merely to immerse the stem of the thermameter in the vapour was not without considerable influence on the distillation ; secondly that both the dephlegmator and the cooling tube produced much better results than the retort and the flask with T-piece; thirdly that the distillation with the cooling tube was rather better than that with the dephleg-mator.Of these results the last alone calls f o r further examination. Strictly speaking the comparison of the distillations c and tl shows that under certain conditions better results can be obtained with a long tube than can be obtained under certain other conditions with a dephlegmator. Those who have had experience witli these forms of apparatus will have observed that tlie rapidity with which the process of distillation is conducted largely influences the result ; the amount of cooling surface also cannot be a mattcr of indifference.In order therefore to compare accurately the two methods and to see whether the dephlegmator has any special value the sevei.al distillations should be effected in the same time and with the same extent of c u 01 i ng surface 54 FRED. D. BROWN THE COJIPARATI’STE VALUE OF FIG. 3. With this object i n vicw I constructed the dephlegmator represented in Fig. 3 ; it consists of a glass tube 500 mm. long and having an internal diameter of 20 mm. This tube carries nine small discs of wire ganze (40 holes to the inch) a piece of brass tube cd 2**> mm. in bore and 45 mm.long is passed through the centre of each disc and soldered to the gauze, SO that about 8 mm. of the tube project above it. The lower end of each picce of tube is deeply notched with a triangular file and sol-dered into a small brass cup d (tlie heads of upholsterer’s brass nails serve admirably for tliese cups). The lower end of the glass tube is fitjted with a cork iato the flask or still to the upper end is adapted an ordinary T-piece. The tubes cd serve to carry away the liquid. from the top of the gauge discs the cup a t the bottom answering as a trap to prevent tlie va-pour passing up the tube instead of going through the gauze. It is essential when No. 40 gauze is used that these tubes should be at least 45 mm. long as the adhesion of the I liquid to the gauze is so considerable that the pressure of the vapour underneath is sufficient to force the liquid out of a shorher tube; with filler gauze a still longer tube mnst of course be employed.IQ the figure the discs of copper gauze are drawn fitted into small rings of cork ; this not only hdds them more firmly but also causes the whole of the condensed liquid to accumulate on their upper sur-faces instead of running down the side of the glass tube; the cork would of course be unsuitable for liquids of high boiling point. This dephlegmetor was constructed only with a view to the ready re-moval of the discs &c. so that the same tube might be used with and without them. ”hi simple construction the absence of fragility and the fact that under no circumstances does it get overloaded with con-Gensed liquid are however advantages which render it preferable to those ordinarily used.I now attempted to carry out two distillations with the same liquid in the same length of time one with the gauze discs the other with-out. I foumd however that this could not be done ewn when a gauge was fitted to the Bunsen burlier used and the gas maintained at a constant pressure by means of a screw clamp. Three distillations mere therefore made with the discs and two without; these as will be men wexe suflicient t o show whether the two methods were identica DIFFEREXT 3IETHODY OF FRACTIOSXL DISTILL4TIOS. 3.3 Number of fraction. T 11 III . . . . . . . . I V I&. or not. In aach case 1000 C.C.of a mixture of benzene and carLon disulphide containing about 62.7 per cent. of C8 was employed. Tlit: density of the benzene a t 19.80* was 0.88049 that of the carbon clisul-phide was 1.26629; they were both carefully purified and their densities w'ere so nearly the same as tl~ose of the liquids previons!y used viz. 0.88034 and 1.26642 that tlie same iable of densities and percentages was employed. The distilltitioil was continued until four fractions of 200 C.C. each had passed over ; it was then stopped and the densities of the four fractioiis and of the residue were observecl ; the results were as follows :-Time occupied in distilling. 23 30 44 97 -Temperature 01 dijtillatim. Density corr. to 19 -80'. I Number of fraction. I .. . . . . . . . . 11 111 1 c lies. Percentagc of cs,. Time occupied iii distilling. -5 1 4 5-1, 52 95 -~~ 11. Distillatimi with yawe discs. 2llixtui.e coiitairu'ng 62-70 ye^ cent. 01' C'S:. Teinpersture of distiU:ttioii. Density Cory. to 19 *SO". Time occupied in distilliiig . I- -Temperature of clist illation. 1.21939 1 .a0705 1,14022 0.94429 0-88019 Percentage of CS:. Suniber of fraction. 1 I 1 111 I v . . . . . . . . Re&. . 85 40 60 73 -Density corr. to 19 -80". 1 228877 1.18359 1.14599 0.92097 0.8305 4 Percentage of CS2. 03 a 83 .8 E 77.987 15 .85 00 '0 56 FRED. D. BROJTN THE COJIPARATIVE VALUE O F Number of fraction. I I1 I11 IV Res.IV. lJistillatlon with same tube without gauze. Dfixtzcre containing 62.74 per cent. of CS,. Tiiiic occupied in distilling. -____ 45 45 40 36 -Density corr. t o 19.80'. Tcmpemture of distillation. Percentage of of CS2. 0 0 - -52.6 58 -6 --54 '9 54.9 -60.8 60.8 -77.2 - -I I Density con. to i9'80". 1.19066 1 86'79 1 '17413 83.63 1 -13420 75 *55 1.01833 47 '31 0 -88756 1 2.93 Percentage of CS,. Number of fraction. 1 * 20960 1.20032 1.14'887 0 *93691 0 -88053 ~ I I1 111 I V Bes. 90 '30 88' 58 78 '57 21.56 0 .oo Time occupied in distilliiig. 225 300 285 225 -Temperature of ~ distillutiou. -58.7 50'7 -54.6 54.6 - 4 6 '1 66.1 -80.5 - -On inspectiiig these numbers we see in the first place that they afford convincing proof of the statement previously made that the rate of distillation is an element of considerable importance showing that the slower the distillation the more carbon disnlpliide does the dis-tillate contain and that this is equally the case whether the vaponrs are washed or not.I n comparing together the percentages of the various fractions it must of course be remembered that only the first fractions of each distillate are strictly comparable for after these had passed over the liquid in the still had no longer the same composition i n each successive distillation. This explains f o r instance why the third fraction of the first distillation contained more CS than that of the third though i t clistilled in a shorter time.I n the first case a less quantity of CS had been previouslyi*ernoved; a t the beginning of the third fraction therefore the liquid in the still was much richer in CS2. These distillations further prove conclusively that the processes of ir:cnshi~ig and of cooliiig are not identical. The fifth distillation was made under the most advantageous circumstances that is it was con-ducted a t the slowest possible rate yet the resclt was decidedly inferior to that of the second in which tlie vapour was washed and ahicli was completed in a fourth of the time. Tlie same remark applies to the fifth and third and to the fourth and first distillations. Since in e q i d times with eqnsl surfaces the radiation must be the same the effect of radiation iii the fifth case must 1iai.e been greater than in the second ; the better result in tlie second case must there DIFFERENT METHODS OF FRACTIONAL DISTILLAITIOS.5 7 fore have been dne to the presence of the gauze discs. A certain amount of secondary distillation does therefore take place in the clephlegmator and the question whether the apparatus has anj- special value is ans-ivered in the afErmative. Notwithstanding this resnlt we are not yet in a position to stfate that the dephlegmator is the best apparatus for fractional distill a t ' ion, and tbat because we have by no means exhausted the resources of the process of cooZ;ng. The mixed vapours in passing up a tiibe may ob-1-iously be subjected t o more and more radiation if the tube be gradu-ally increased in length until a t last no vapour mill reach the top of the tuhe ; the best possible result will be obtained when the vapour just creeps over the top before complete condeiisation takes place, having then reached its lowest possible temperature.It would of course be impracticable to effect distillations in this way but the object. in view is readily attained by passing the vapours through a tube or still head maintained a t a given temperature as is done every day when distillations are carried out on a manufacturing scale. If the temperature of the still head be the lowest possible compatible with the passage of vapour into the condenser the result will be the best which the process admits of. The next stepin this investigation was therefore to make a suitable apparatus f o r the above purposes the general finally adopted is shown in Fig.4. The still A conimunicates with a coil C ter-minating in a vertical portion open a t the top, into which a thermometer is fitted witJh a coFk in the usual manner; a lateral tube B serves t o conduct the vapour from the coil into the condenser. The whole of the coil C including the junction with the tube B is enclosed in a cylindrical copper box 300 mm. long by 110 mm. in diameter. The two ends of this cylinder are tied to-gether by means of the copper tube aa which not only strengthens the cylinder but being open a t the top serves for the introduction of a second therinometer which indicates its tem-perature. This copper box is filled lip to the level I with a liquid or mixture of liquids boiling at the required temperature the heat being furnished by a ring burner 217~.The vapour given off by this boiling liquid passes LIP the tube dd to the condenser F whence it returns in a liquid form by the tube kk to t'he bottom of the box E. character of the one FIG. 4 58 FRED. D. BR0TT-X THE COMPARATIVE VALUE OF The small tube m serves as a communication with the atmosphere. As there is considerable trouble in changing from one liquid to another when a different temperature is required the apparatus is cornpletcly closed except a t 112 by connecting with an air chamber, iiz which any constant pressure can be conveniently maintained ; the boiling point of the liquid in E can be altered a t will. With a view to the use of the apparstns in this manner the copper box E and the tubes connected with i t were tested a t a pressure of 100 Ib.on the square inch. . I n employing this apparatus the ring burner bb is first lighted, when the liquid in E begins to boil the teniperature as indicated by tbe thermometer in aa (this. tube is filled with water or petroleum) soon becomes const,ant and at the same time the readin$ of the ther-mometer placed in the top of the coil ceases to vary; heat is then applied t o ths still A and the distillation carried out as rapidly as can be done without altering the reading of the thermometer in the coil. For the first dist,illation made with this apparatus methylated spirit was put in the box E and the pressure maintained was such that ebullition took place at about 57".About 800 grams of a mixture of benzene and carbon disulphide were put in the still A and the distil-lation collected i n 10 fractions. The mixture i n the still a t the beginning of the distillation con-tained 45.00 per cent. of CS ; a t the end it contained 26.56 per cent. The barometric pressure daring the distillation was 750.7 mm. The thermometer H was placed in an the therinonieter F in the t3p of the coil. The dehails of the distillation were as follows :-No. of fraction. I I1 . I . . JV v . . . . V I VII VIII IX x in . . . . Readiilg of B m-11 en frac t ion remored. 57 -50 57 -50 57 -50 57.50 57.52 57 -51 57 5 3 57 *53 57 -53 57 -53 --Reading of F2 whcn fraction removed.57 -10 57 '10 57.1C 57 -10 57 * I 2 57.10 57 . I 2 57 '30 58 *OO 57 -90 Density of frao-tion at 19SO". 1 '13523 1'13185 1 .I3348 1 -13528 1 -1364.9 1 *136,36 1 -13733 1.13819 1.13358 1-13333 Percentage of CS2 in fraction. 7 5 9 3 75.02 75.36 75 -74 7 5 -99 76 *01 76 *17 76 *35 73 *38 75 -33 The slight rise in the reading of I? towards t'he end of the distilla-tion was due to the vapour passing too rapidly through the coil ; it did not seem however to have any influence on the composition of the distillate DIFFEREXT METHODS OF FRAACTIONAL DISTILL-ITIOS'. 5:) A second distillation was made with 600 grams of a mixture con-taining 11.47 per cent. of CS ; tlie barometric pressure was 753.1 mm. At the end of the experiment the liquid remaining in the still con-tained only 4.33 per cent.of CS ; the details were as follows :-Dcnsity of frac-tion at 19.80". -98826 -98516 *98498 -98527 No. of fraction. LI_-I . . . . I1 I11 I V . . Percentage of CSL. - ~ ~ _ _ _ I 3s -44 37'48 37 '42 37.5% 70 -29 70.35 70.57 70.56 69 -94 69.98 70 23 70.24 These two distillations show that the composition of the distillate is independent of the amount OP carbon disulphide in the still but varies with the temperature of the coil or still head. Two distillations were now made with the copper cylinder E filled with pure carbon disulphide the boiling point of this liquid being evidently the lowest temperature a t which any vapour given off by a mixture of benzene and carbon disulphide can pass into the con-denser.I n the first of these distillations a mixture containing 42-61) per cent. of CS was employed while the residue in the still when the experiment was stopped contained 32.37 per cent. of CS?; the amount of CS in the various fractions of the distillate was found to vary between 9'7.32 per cent. and 98.72 per cent. The distillate did not gradually increase or diminish in density the higher and lower Fercentages following each other indiscriminately. I n the second clis-tillation for which the liquid remaining from tlie first \vas used the liquid in the still contairied at the beginning 32-37 per cent. and at the end 25.21 per cent. of CS2 ; in this case the amount of CS2 in the distillate varied from 97-48 per cent to 99-19 per cent.These two experiments show that when the stiil head is maintained at a temperature equal to the boiling point of the most volatile com-pound in a mixture that compound alone or nearly alone passes over into the condenser; it is therefore possible by the use of this appa-ratus to effect an almost complete separation of the various constituents of a mixture of volatile substances in one dishillation. I n order to show the practical value of the method I may mention that I have frequent1.y used it t o separate benzene from the toluene and other substances which ordinary commercial benzne contains in large qnant i ties. As an examplc the following rectification of some crude benzene will suffice. A sample of 200 C.C.of this liquid was distilled in an ordinary flask ; i t The benzene thus obtained has always been nearly pure GO ML'XR AND SLhTElC INFLUENCE OF WATER began t o distil a t 8.5" ; a t 90" 120 C.C. had accumulated in the receiver, a t '3.5" 153 c.c. at 100" 168 c.c. a t 105" 170 c.c. and a t 110" 192 C.C. 1100 C.C. of this very impure liquid were distilled with the apparatus above described maintained a t a temperature of 81° ; this was rather too high to give a really good result ; nevertheless 500 C.C. of rectified benzene were obtained of which a sample of 'LO0 C.C. distilled as 101-lows :-Distillation commenced a t 80.0" ; a t 80.4' 155 c.c. a t 80.8" 176 c.c. a t 81.0" 180 c.c. arid a t 83.0" 191 C.G. had accumulated in the receiver. When 500 C.C. of this rectified benzene had passed over the experiment was stopped and a sample of the residue distilled as follocw :-Distillation commenced at 91" ; a t 95" 80 c.c. a t 100" 130 c.c., a t 105" 158 c.c. a t 110" 186 C.C. had passed into the receiver ; it is therefore seen from how impure a liquid pure benzene niay be directly obtained. As regards the results contaiiied in the above paper it niay be con-tended that they present but little novelty ; it was liowevei* necessary That tbe effects obtained by the different niethods should be exactly defined and numerically stated before a complete explanation of iractional distillation could be advanced

ISSN:0368-1645    

DOI:10.1039/CT8803700049

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

60 MUIR AND SLATEH INFLUENCE OF WATER TI.-CONTRIBUTIONS FROM THE LABORATORY OF GONVILLE AND CAIIJS COLLEGE CAMBRIDGE. S o . 1K-00’1~ the Iuflueiice exerted upon the Course of Cejtcx,in Chemical Changes by Variations i n the A m o u n t of IVutey of Bilutiou. By 1\f. %I. PATTISON J I U I R Caius P r d e c t o r i n Cliemistry and CHAS. SLATER B.A. Scholar of St. John’s College. 1. In a paper by one of us (this Journal 1879 Trans. p. 311) an experimental examination was made of some of tlie conditions which affcct the equilibrium of the system CaCI + Na2C0 + zHLO. I t was there suggestted t h a t a study of tlie changes undergone by this sgsteni under conditions such t h a t the action of the various forces might be more disentangled from one another would he advisable.The present paper cmtains the results of experiments undertaken with the object of determining the influence on the equilibrinrn of the system of variations in the quantity of water present. 2. The solutions use2 contained respectively 320.7 mgrms. CxC1 in 10 c.c. and 305.54 mgrms. NazCO in 8.1 C.C. The sodium carbonat PLATEL (TABLE 1) CaCI and Na&O,. 1 1 molecules. 30minutes. l.8” Brrison & Sons. Lith. S Martins Lane,JK C OX T€IE COURSE OF CERTAI?; CIIEJIIC-IL CH-1NGES. 61 was added to the calcium chloride solution and the whole was then shaken up. Initial condition was CaCl Na,C03 H,O = 1 1 330 mols. Each 25 C.C. water added = 470 mols. Time = 30 minutes. Temp. = 16-18'. TABLE I. Mean percentage Water added. of CsCO3 In C.C. I n inols.produced. I 0 330 97.8 25 800 96.3 50 1270 96.0 95.1 75 1740 95.5 95.7 100 2210 93.8 94.6 200 4090 91-2 91.2 300 5970 $6.3 85.9 400 7850 $5.8 85.8 500 9730 82.1 i8.7 Actnnl numbem obtained. 97.5 96.8 96.03 95.4 93.1 91.2 85.9 85.8 78.7 98.2 96.1 96.03 96.03 96.03 96.08 9.3% 95.8 94.3 93.3 91.9 87.1 85.6 85.3 Another solution was used after this point. 10 C.C. CaC12 = Initial state = 1 1 2700 mols. Each 25 C.C. water added = 55.5 mgrms. 2700 mols. Water aacled. Mcnn percentage of &tual numbers I n C . C . I n iiiols. C'uCO produced. obtained. 100 12.500 75.0 175 20,600 66.5 66.0 67:O 200 23,300 62.2 62.2 225 26,000 52.0 52.0 The results contained in this table are graphically represented in the curve of Plate I.3. Thme results show that in the special case considered the amount of chemical change decreases regularly as the amount of water of dilution increases. The water which is added a'ppears to exert a purely mechanical influence on the change under consideration. We may suppose that the chances of collision between the mole-cules of sodium carbonate and calcium chloride are decreased the greater the number of inactive water molecules interposed. 4. I n the second series of experiments which we conducted the influence of water on the reaction SrC1 + H2S04 = SrS04 + 2HC1 was studied. The results obtained meTe very discrepant and seemed to allow of no reasonable geiiernlisation being deduced. These results will be referred to in the seqnel. 5. The reaction BaCl + R2C2Q4 = RaC,O + 2KCl xppcared t 6 2 BlUIR XSD SLXTER INFLUESCE OF W-iTER present a chemical change well adapted for the study of the influence of dilution.Barium oxalate is tolerably insoluble in water and the amount of change can be quickly and accurately determined by nieasuring the Quantity of undecomposed potnssiutn oxalate by titration with stan-dardised permanganate. The experiments were conducted by adding a measnred volume of potassium oxalate solution to the proper quantity d € solution of barium chloride previously diluted with a measured volume of water shaking up and then allowing to remain a t rest. At tlie close of the time allowed for the change to proceed a portion of the clear liquid was drawn off and run through a dr7 filter into n dry heaker and the amount of potamium oxalate in solution was determiried in an aliquot portion of this filtrate.TABLE 11. 10 C.C. BxCI solution used = 627.04 mgrms. BaC1 9.35 C.C. K,C204 Initial condition = BaC1 K,C,O H,O = 1 1 360 mols. solution used = 501.03 mgrms. Each 25 C.C. water added = 460 mols. 16-18'. Mean percentage of Water added. BaC1 decom-I n C.C. In mols. posed. 0 360 90 2 25 820 88.5 5 0 1,250 8 7.6 100 2,200 79.8 250 4,960 70.3 300 5,880 69.1 350 6,800 63.2 400 7,720 56.8 600 11,400 46.0 200 4,040 74.8 Time = 30 rnins. Temp. = Kumbers actually obtained. -89-09 91.32 88.2 88 s 57-5 87.8 79.1 80.2 79.3 79.9 75.0 74.5 70.4 SO.1 70.0 67.8 69.5 62.8 63.5 57.5 57.5 55.4 43.0 49.0 These results are represented graphically in Curve ,4 Plate 11.6. The generalisation of par. 3 may me think be also deduced from these results. The amount of chemical change decreases regularly as the amount of water of dilution increases. 7. Another serie3 of experiments was conducted similar to the fore-going save that the beakers in which the change proceeded were surrounded by ice TABLE 111. Details as before. Temp. = 3". Time = 30 miiis. Water zdcled. I l c m pcrccntnge of In C.C. In iiiols. UaCl; decomposrd. Numbers actually obtained. 0 360 25 820 100 2,200 200 4,049 3.00 5,860 400 T,720 coo 11,400 7wo 13,240 These results are represented grapkically in Curve B Plate T I . 8. In the nest series of expwiments we made the time longer still keeping the temperature low.TABLE ITT. Details 3s hefore. Temp. = 3". Time = 98 mins. Water added. In C.C. In moh. 2 3 F10 100 200 300 400 500 GOO i00 800 820 1,280 2,200 4,043 5,880 7,7 20 9,560 11,101) 13,240 15,080 Mean percentage of BsCI, 98-1 92.0 83-9 71.5 63.7 44.6 30.7 20.1 24.4 decomposed. 9". r / 3 These results are represented graphically in Curve C Plate IT. 9. We now raised the temperature keeping the time the same as before 6 4 MUIR AND SLATER INFLUENCE OF WATER TABLE V. Details as before. Temp. = 18". Time = 90 mins. Water added. In C.C. In mols. 25 820 50 1,280 100 2,200 200 4,040 300 5,880 400 7,720 500 9,560 600 11,400 $00 13,240 800 15,080 Mean percentage of BaC1, decomposed.Numbers actually ohtnin d. 98.2 98.2 96.3 96.8 96.3 94.0 95-5 92.5 88.2 91-2 85.2 80.5 81.4 79.7 67.0 63.9 65-1 49-9 47.4 52.4 31.5 34.2 32.2 33.7 31.8 24.8 - 24.8 10.3 10.3 10.8 9.7 These results are graphically represented in Curve n Plate 11. 10. Curve I3 (Plate 11) seems to us to show tliat with a low tem-yerature and a short time (30 minutes) the process of chemical change is retarded to a proportioiiately greater extent by a large, than by n small quantity of water of dilution. Curve C which ex-hibits the inffuencle of the water of dilution a t a low temperatuw but when the change is alloned to proceed for a longer time (90 minutes) shows the same ;rregularity in the action of the diluting water. And from Curve D m7e conclude that when the change is allowed t o proceed for a considerable time (90 minutes) the retarding influence exerted by large masses of dilating water is proportionately greater than that exerted by small masses even whan the temperature is allowed to rise to 1 6 O or 18".11. In order to explain these results we advance the hypothesis that under the conditions of experiment a number of hydrates of barium chloride tend to form in the solution. Among these hydrates we re-gard the cryohydrate as occupying an important place. At moderate temperatures (18") and short times (30 minutes) we suppose that the tendency to formation of cr-j-o1i-j-drate is very small ; lienco the regular action of the \water of dilution (Curve A). ,4t low ternperatnres however even if the time be short the cryohydrate (alonq witjh other hydrates doubtless) tends to form and being pro-duced in presence of a large mass of one of the products of its own dissociation this cryohydrate is somewhat stable.The greater the inass of water the greater the stability of the cryohpdrate other con-ditioiis being constant and any secondary action which may be exerted by the water being disregarded. When we make the time of action I O I I ~ C T tho tcnde~cy to formatio P E R C E N T A G E O F C H E M I C A L C H A N G E Harndon & Sons Lith 3 hlarhns Lane T+'- ON THE COURSE OF CERTAIN CHEMICAL CHANGES. 65 of cryohydrate might be expected to become greater and therefore the Curve C might be expected to approach to or even to overlap the Curve B.But long time of action increases the chance of molecular collisions and hence of molecular decompositions. Curve C keeps always above Curve B but exhibits the same general form. But that time does tend to production of cryohydrate (by our hypo-thesis) even when temperature rather tends to dissociation of the same provided the presence of a large quantity of the liquid product of such dissociation be insured is shown by Curve D which exhibits much the same general form as B and C. Now the association of water molecules to the molecules of barium chloride must be attended with loss of energy from the entire system, hence the amount of chemical change becomes proportionately less as the velocity of formation of these complex niolecules (by hypothesis) increases.12. In the next series of experiments the condition of time was arranged so that the precipitated barium oxalate should have com-pletely settled down leaving a clear supernatant liquid before the close of the action A portion of the clear liquid was drawn off by means of a pipette and aspirating arrangement and the quantity of undecomposed oxalate was determined therein without previous fil-tration. TABLE VI.-Pipetting. Details as before. Time = 90 mins. Temp. = 3". Water added. In C.C. In rnols. 25 820 50 1,280 200 4,040 300 5,880 400 7,720 500 9,560 600 11,400 700 13,240 800 15,080 100 2,200 Mean percentage of BaCl decorn-posed. 98.1 97.5 91.6 82.0 67.8 58.0 41.8 27.6 15.0 5.0 Numbers actually obtained./-A \ 98.1 97.5 97.5 92.1 91.1 81.6 82-5 68.4 67.2 58.3 57.8 42.8 40.8 26.2 29.0 12.9 16.6 10.2 18.1 17.2 4.5 5.5 Curve A Plate III represents these results in graphic form. 13. A series of experiments similar to those just detailed was carried out at a higher temperature. VOL. XYXVlI. 66 MUIR AND SLATER INFLUENCE OF WATER TABLE VIL-Pipetting. Details as before. Time = 90 mins. Temp. = 16-18”. Water added. In C.C. In mols. 25 50 100 200 300 400 500 600 700 800 820 1,280 2,200 4,040 5,880 7,720 9,560 11,400 13,2# 15,080 Mean percentage of BaC1 decom-posed. 98.2 96.4 93.5 88.4 80.0 65.9 44.3 31-2 -20-6 4.5 Numbers actually obtained. ‘98.2 96.3 94.5 90.9 80.0 68.2 42.8 31.4 18.6 40 7 - - A 96.8 96.0 -92.5 - -85.9 - -80.0 - -63.7 - -45.8 - -31.8 30.6 31.0 18.9 24.4 -4.0 5.5 -See Curve B Plate 111.14. These results are we think in keeping with the hypothesis of par. 11. Curve A shows it is true an almost regular retarding influence exerted by the water of dilution but we believe that the “pipetting method” of estimation is more delicate than the “ filtration method,” and that the inflnonce of formation of cryohydrate &c. is shown by the former method in the early as well as in the later portions of the curve. Curve B where the temperature is higher and therefore. where one of the conditions of formation of cryohydrate is not fulfilled, exhibits the special influence of water of dilution under consideration only when the quantity of water becomes somewhat large.The same general deduction may be made from the analogous filtration Curve D, Plate 11. 15. I n repeating some determinations in succeeding portions of the same liquid filtered from barium oxalate we were astonished to find great discrepancies between the results. If 50 C.C. were withdrawn from the filtrate immediately that or approximately that quantity of liquid had passed through the filter the quantity of undecomposed oxalate therein was found to be considerably greater than the quantity contained in the succeeding 50 C.C. withdrawn from the filtrate filtra-tion being continued with little or no intermission. We therefore made a series of determinations of the influence of water of dilution on the change under consideration the data being obtained from estimation of undecomposed oxalate contained in the second 50 C.C.of liquid which passed through the filter ' 3 0 N V H 3 l V 3 l W 3 H 3 d 0 3 3 V I N 3 3 t l 3 PLATE v. ( T~~~ mrr). BaCl and K2CZ04. 1 r l molc?rulea. IHrrison k Sons. Lith. S Martins Lane.W. C ON THE COURSE OF CERTAIK CHEMICAL CHANGES. 67 TABLE VIII.-Xeco.nd Filtrates. Series A. Details as before. Water added. Time = 90 rnins. Temp. = 3". Mean percentage of BaClz I n C.C. I n mols. decomposed. Numbers actually obtained. 190 2,200 93.4 93.7 93.1 300 5,880 71.6 70.0 73.2 500 9,560 52.6 50.8 54-4 ti00 11,400 3 4.9 32.5 37.3 700 13,240 34.2 32.5 36.0 Series B. Time = 90 mins. Temp. = 18". 100 2,200 9.5.4 96.0 94.8 200 4,040 890 91.5 86.5 300 5,8f30 80.8 81-9 79-7 400 7,320 67.4 69.9 65.0 500 9,560 51.1 53.8 48.4 600 11,400 35.3 36-0 34.7 700 13,240 32.5 35.7 32.3 31.0 30.4 In Plates IV and V these results are graphically represented by Curves A and A' respectively.The Curves B and C of Plate IV and B' and C' of Plate V represent the results of " pipetting " and- " first filtrate " determinations cnder the same conditions of time and tem-perature as those under which the data of A and A' were deter-mined. 16. From the curves of Plate IV it is apparent that the influence exerted by water of dilution on the chemical change under considera-tion a t low temperatures and moderate degrees of dilution is much the same whether the data be obtained by analyses of the liquids removed from above the precipitated barium oxalate by pipetting, o r by filtration.When however large amounts of water are added, the results show considerable differences according as the pipetting or filtration process is adopted the latter process exhibiting the change as proceeding to a greater extent than the former. We think that these results may be explained by supposing that a t a low temperature and with much water the tendency to formation of cryohydrate reaches a maximum and that under these conditions the whole system of chemical molecules is thrown into a state of strain from which it is partly relieved by the process of filtration the result of this relief being that the molecular equilibrium is upset and that the velocity of the decomposition of barium chloride by potas-sium oxalate is suddenly increased.If there be elements of truth in this explanation we should expect to find smaller differences in the results obtained by the methods-F 68 MUIR AND SLATER INE'LUEKCE OF WATER pipetting and fi Itration-when the condit,ions of experiment were rendered less favourable to formation of cryohydrate molecules. One less favourable condition is maintenance of higher temperature. The curves of Plate V (when compared with those of Plate IT) show that the results obtained from " pipetted liquid," " first filtrate," and " second filtrate " respectively agree much more closely when the temperature is 18" than when the terr,perature is 3'. Again with small quantities of water of dilution.i.e. with a condition unfavourable to formation of cryohydrate the differences between t'he results obtained by the " pipetting," and those by the '' first filtrate " methods are reduced almost to zero even a t 3" ; at this temperature " pipetted " results differ slightly but only sliqhtly from " second filtrate " results while a t 18" the results obtained by both methods are almost identical. A small number of experiments carried out at a higher temperature 50" showed that identical results are obtained a t this temperature by the three methods with a dilution of 400 C.C. and 800 C.C. It is difficult to foretell what influence would be exerted on the general stability of the system a t a lorn temperature by variations in the time of action. The numbers obtained by us seem to show that the system is in a state of greater strain a t 3" after the expiry of 30 minutes than when 90 minutes have elapsed.Thus the mean percentages of barium chloride decomposed a t 3" after 30 minutes' action as measured by analysis of the first and second 50 C.C. of filtrate were respectively :-C . C . water added. First 50 C.C. Second 50 C . C . Difference. 100 74.8 77-3 2.5 300 61.2 71.4 10-2 400 45.8 68.4 22.6 The results obtained under the same conditions save making time = 90 minutes are stated for sake of comparison. C . C . water. First 50 C.C. Second 50 C.C. Difference. 100 '32.0 93.4 1.4 300 71.5 71.6 0.1 400 63.7 65.0 1.3 The system would thus appear to be in a state of maximum strain when the conditions favourable for formation of cryohydrate are ensured viz.low temperature and much water and when the time of action is short. We are almost inclined to believe that under these conditions the cryohydrate molecules are in process of formation, whilst after a longer time the molecules are to a great extent formed ON THE COURSE OF CERTAIK CIIEMICAL CHANGES. 69 a,nd that therefore the system although yet very unstable is neverthe-less more stable than it was under the former time conditions. 17. We do not attempt to propound any exact hypothesis as to the action of the filter in inducing a sudden increase in the velocity of the chemical change. It may be that the reacting molecules are brought into closer contact i n the pores of the filter,* or it may be that when a portion of the liquid the constituents of which are by our hypothesis in a state of strain is removed from the main liquid decomposition is induced in the separated portion by the small change of temperature which is undergone by the solution during its passage through the filter or perhaps by tlie mechanical action of the surface of paper to which the solution is for a time exposed.A few determinations were niade of the amount of change when calculated from data obtained by analyses of the third 50 C.C. of filtrate. These determinations were almost identical with those obtained from the second 50 c.c. but considerably higher than those obtained from the first 50 C.C. of filtrate. The results obtained by the pipetting and filtration methods are stated in percentages of total barium chloride decomposed the rapid change which occurs while filtering under certain conditions of dilu-tion and temperature occurs in that small isolated portion of the general chemical system which is placed upon the filter but the amount of change is calculated as if that change proceeded to the same extent within the whole liquid.The exposure of the whole liquid to a veyy slightly higher temperature or to passage through a filter would not necessarily produce a change to the same extent as is produced in the small isolati d portion. Certain experiments which we have not as yet continued seemed to show tliat if when strontium sulphate is precipitated from a dilute solution of the chloride by addition of sulphuric acid and when tile liquid abore the precipitate is perfectly clear a portion of this clear liquid be isolated from the main portion by wit,hdrawal in a pipette the clear liquid so isolated quickly becomes turbid because of r en e w c d pr e ci p i t a t i o n of strontium s ul p h ate .18. The individual results contained in many of the foregoing tables shorn7 considerable discrepancies among themselves ; these discrepan-cies art. not however in our opinion contradictory of the hypothesis which we have zdvanced. The method of determining the amount of chemical change which we have used is fitted to give fairly accurate results if the mean of several determinations be adopted but the occurrence of small differ-ences between the numbers actually obtained is to be expected. The discrepancies are most marked when dealing with dilute solu-* In connection with this compare Baylej this Jomnal 1878 Trans.p. 304 '70 MUIR AND SLATER INFLUENCE OF WATER tions a low temperature and a short time of action ; they become leas marked when the temperature is high the solutions less dilute or the time longer ; further the results obtained by the " pipetting " method show on the whole fewer discrepancies than those obtained by the method of " filtration." In other words when the system is by hypo-thesis in a condition of strain differences between the individual results are noticeable but when the conditions favourable to production of such strain are removed the discrepancies among the individual results tend also to disappear. 19. In paragraph 4 it was stated that the influence of water of dilution on the reaction between strontium chloride and sulphuric acid had been examined but that the numbers obtained led apparently to no general results.We think that the great discrepancies noticed between the numbers obtained may be explained by the hypothesis already advanced. Sulphuric acid forms many hydrates with water and is doubtless able to attach to itself large numbers of water molecules. If our hypcthesis be true we should expect a system containing sul-phuric acid much water and such a salt as strontium chloride to be in an eminently strained condition and therefore to be capable of having its equilibrium upset by very small amounts of impressed force. Mow unless very special precautions were taken to maintain the conditions of each experiment altogether unchanged during the whole course of that experiment and unless a very delicate method of deter-mining the amount of change under given condit,ions were adopted, we should expect to obtain discordant results.But we did not adopt such speciaZ precaution nor was the method of measuring the amount of change characterised by extreme delicacy.* The results obtained were therefore discordant as indeed we shouId expect them to be if our hypothesis be correct. We subjoin a few of the actual numbers obtained. * The method consisted in filtering a portion of the clear liquid precipitating undecornposed strontium chloride as carbonate dissolving in standard acid and determining residual acid by titration with standard alkali PLATE VI.( TABLE. X). BaZNO.pnd &C,0,=1:lmoleoules ON THE COURSE OF CERTAIN CHEMICAL CHANGES. 71 TABLE TX.-Strontium Chloride and Xulphuric Acid. 20 C.C. SrC1 solution used = 354.64 mgrms. SrCI,. 878 C.C. H,SOk solution used = 877.52 mgrms. H2S0,. SrC12 H,SO = 1 4 mols. Temp. = 16-18". Percentage of SrC12 decomposed. h C.C. water added. %me = 60 mins. Time = 18 hour; r - 25 50 75 100 125 150 175 200 225 250 759 - -73.6 -62.9 66.1 77.3 52.8 67.2 64.7 47-7 - -33.7 49.6 -46.2 -27.4 -29.7 - -27.8 - ----Time = 60 mins. SrC1 €€,SOa = 1 2.5 mols. 25 70.1 67.5 85.5 -50 745 60.4 56.4 -90 52.0 53.0 -100 49.5 51-7 55.1 -125 45.2 51.1 39.4 50.2 150 36.9 2'2.5 21.5 32.2 175 14.2 24.8 10.6 -20.As a further test of the value of our hypothesis we carried out a short series of determinations of the influence of water of dilution on the change which occurs when barium nitrate is decomposed by meam of potassium oxztlate. TABLE X.- Barium Nitrate and Potassium Oxalate. Used 10 C.C. Ba2N03 solution = 800 mgrms. Ba2N03 and 9.4 C.C. KzC204 solution = 509 mgrms. K2C20a. Ba2N03 K2C204 = 1 1 mols. Pipetting. Time = 90 mins. Percentage Bs2N0 decomposed. -L C.C. water added. 3". 18". ' 100 85.4 91-8 300 38.9 76.4 500 39.4 50.3 700 9.1 25. 72 MUIR AND SLATER INFLUENCE OF WATER Filtration (first 50 c.c.) results. Time = 90 mins. Temp. = 3". C.C. water added. 0 25 50 100 300 500 700 Percentage Ba2N0 decomposed. 98.7 96.9 95.8 83-0 70.5 53.0 29.5 These results are represented graphically in Curves A B and C, Plate VI.The " pipetted '' results show little or no indication of formation of hydrates in the " filtered " results on the other hand such indication is clearly shown when the quantity of water of dilution becomes con-siderable. 21. We subjoin certain data taken from Guthrie's papers regarding the cryohydrates of the salts employed by us. BaCI2.2H,O cryohydrate solidifies a t - 8" with 37 mols. of water. SrC12.6H20 37 9 9 -17" 7 ) 23 > 7 CaC12.3HzO 9 7 9 7 -37" , 12 7 7 Ba2N03 Y 7 7 7 - 0.8" , 259 7 7 K C 2 0 4 7 7 7 7 + 6.3" , 17 9 7 I n the reaction in which calcium chloride was decomposed by addition of sodium carbonate the influence of water of dilution on the change was regular; because on our hypothesis the tendency to formation of the cryohydrate of calcium chloride is but feebly marked under any ex-perimental conditions realised by us.I n the reaction between barium nitrate and potassium oxalate the influence of water of dilution is regular ; because the cryohydrate of barium nitrate tends to be formed in considerable quantity under the experimental conditions employed. B u t if the determinations of the amount of change are made in the filtered liquid then the results show large differences from those obtained by the " pipetting " method ; because the equilibrium of the system although sufficiently stable to resist overthrow by the mere process of pipetting off a portion thereof is nevertheless disturbed by the process of filtration.Further the influence of water of dilution on the change which occurs when barium chloride and potassium oxalate mutually react, is irregular ; because-on our hypothesis-the cryoliydrate of barium chloride tends to be formed under the conditions of experiment but not to be formed to such an extent as renders the system compara-tively stable Hardson k Sons.Lith. s' Martins Lane.W ON THE COURSE O F CERTAIN CHENICBL CHANGES. 73 A comparison of the " filtration " and " pipetted " curves for barium nitrate with those for barium chloride under the same conditions of temperature and time (A and C Plate TI with C and B Plate IT), shows that the difference between the results obtained by the two methods is much greater in the case of the nitrate than in that of the chloride.On our view of the influence of water of dilution the very stability of the barium nitrate solution (because of the large formation of cryo-hydrate) would be looked on as the reason why when that stability is overthrown the velocity of the chemical change is so largely in-creased. 22. But there is an aspect of the influence of water of dilution other than that which we have hitherto regarded. The addition of much water might be supposed to bestow upon the reacting system a greater degree of molecular mobilit,y than would be possessed by a more concentrated solution. Chemical change should therefore occur with greater readiness in the former than in the latter liquid. Rut a t the same time the chances of molecnlnr encounters, and therefore of molecular decompositions occurring in unit time must be smaller in dilute than in concentrated liquids notwithstanding the greater niobility of the former sjstcm.Therefore we should conclude that the influence on the chemical change of small impressed forces would be more marked in dilute than in less dilute solutions while a t the same time the total amount of change under the same conditions would be greater in the more concentrated solutions. Deville (PM. Mnij. [4] 32 365) has advanced a theory of the influence of dilution in which he supposes that energy of position is a,ctually gained by the reacting molecules when dilution is increased, and that this energy may be changed into mechanical work wherebr again heat may be evolved sufficient t o raise some of the chemically active molecules present to their dissociation- temperature i e .to sliatter them into their constituent atoms. But without pushing the influence of dilution so far as this we think we are justified in supposing that in addition to the loss of energy involved in the formation of complex (cryohydrate) molecules there would be a gain of mobility in the case'of those molecules of the reacting bodies which had not thus associated to themselves large num-bers of water molecules. Dilution would thus exert two more or less opposing actions. The general result of a series of experiments carried out by one of XIS,* is in keeping with the hypothetical deduction that impressed force should produce greater diflerences in the amount of chemical change when dilute than when more Concentrated solutions are used.* See nest paper 74 MUIR AND SLATER IXFLUESCE OF WATER 23. How should t,ime influence the process of chemical change, specially studied by us when taking place in dilute solutions as compured with the influence OF the same variable on the same change occurring in more concentrated solutions ? The influence exerted by time we should expect to vary according as a low or a high temperature is maint,ained. At a low temperature formation of cryohydrate would tend to be increased by increasing time of action ; but if dilution act by increasing molecular mobility as well as by increasing formation of complex (cryohydrate) molecules we should almost expect that the differences between the total amounts of change, in long and in short times would be less in dilute than in concen-trated solutions.In a tolerably concentrated solution a t a low temperature we have, by hypotlhesis a tendency to formation of cryohydrate molecules ; water is added and thereby the tendency aforesaid is increased but simultaneously molecular mobility is imparted to the system ; the greater the amount of mobility the more rapidly will the chcmical change proceed in other words in dilute solutions the cheniical change will complete itself more rapidly than in less dilute solutions. Now if the tendency to formation of cryohydrate be small e.g. if temperature be somewhat high tjhe influence of time shonld probably be less marked than if the tendency to formation of crgohydrate be large.The results already detailed are arranged in graphic form in Plate VII with the view of illustrating the influence of time. Curves A and B which represent results obtained a t So show little difference between the action of time in concentrated and in dilute solutlions ; but Curves C and D show that a t a higher temperature ( l 8 O ) the influence of time is less marked when much water of dilution is present. If however the difference between the times of action were made very considerable the temperature being somewhat higher than that at which cryohydrate may be supposed to form rapidly then we think that the curves representing the results a t the two times should diverge largely. Now the curves of Plate VIII representing results after 90 minutes (A) and after 5 hours (B) at 18" diverge very largely.The following table contains the results obtained for 5 hours' action at 18" by the pipettiug met'hod (Curve B of Plate VIII) :-It is not easy to answer this question on & priori grounds PLATE Vn. BaCI d K&O,. 1 1 molecules. - 18'. Harrison k Sons. Lith. S! Martins Lane. W. ON THE COURSE OF CERTAIN CIIEXICAL CHASGES. 75 C.C. water added. 50 100 300 500 700 900 1100 Mean percentage of BaC1, decomposed. 97.6 95.6 85.2 75.7 59.3 44.7 18.7 Numbers actually obtained. 95.6 93.6 85.5 84.9 77.4 74.1 60.4 58.1 441.7 -18.3 19-1 24. Every chemical system appears to tend towards that condition of equilibrium the attainment of which is marked by the greatest loss of energy.It may perhaps be more correct to say that the entropy of chemical systems &.,-that portion of the energy which, being dependent on the configuration of the parts of the system is available as mechanical energy,-continually tends to become less. This tendency t o dissipation of energy may be arrested in various ways among others by impressing upon the system what may perhaps be described as an artificial state of equilibriuni. Thus the condition of most stable equilibrium for a system origi-nally consisting of barium chloride and potassium oxalate molecules, would be that in which barium oxalate and potassium chloride mole-cules are produced but by adding much water a portion of thereacting molecules are by our hypothesis loaded with water of hydration.In this loading energy is lost, but less energy than would be lost by the formation of molecules of potassium chloride and barium oxalate ; the system is therefore in an unstable condition but a certain degree of stability is impressed upon it by the presence of a large mass of one of the products of dissociation of the complex and unsta'ble hydrated molecules. We have thus a system in a state of strain because of the stress between its parts. A small force may be sufEicient to relieve the strain, and this relief may be attended with a rapid rearrangement of the p a t s of the system and with a large decrease in the entropy of the system. * 25. If the state of the system which we have endeavoured t o picture in the foregoing sentences be at all correspondent with the actual state of the system we should expect small differences in physical conditions to produce much greater variations in the amount of chemical change in dilute than in more concentrated solutions.The following results are in keeping with this supposition :-* We seem to have here an action opposed to that designated '' chemical induction," by Bunsen and Roscoe (Phil. Trans. 185'7). The state of a system of heterogeneous iiiolecules capable of mutual chemical action is compared by these chemists to tha 76 MTJIR AND SLATER INFLUENCE OF WATER TABLE XI.-Pipetting. BaCl K,C,O = 1 1 mol. Temp. = 20". Water of dilu-tion = 1100 C.C. Percentage of BaC1 decomposed. 7 -,\ Time = 5 hours. Diff. Tinie = 28 hours. DifT. Roughened beaker .. 31.2 34.8 3.8 67.8 66.3 1.5 Broken glass in beaker . . . . . . . . . . 9.7 39.8 30.1 66.3 60.6 5.7 Oxalate added with constant stirring. . 11.0 37.0 26.0 67-1 59.9 '7.2 Oxalate added on sur-face; after 15 minutes whole stirred up. . 14.0 39.1 2.5.1 62.7 62.1 0.6 Temp. = 20". Time = 90 mins. Percentage of BaClz decomposed. Dilution = 800 C.C. Diff. Dilution = 700c.c. Diff? r A rConghened beaker . . 1.5 3.5 2.0 24.3 21.7 2% Broken glass in beaker . . . . . . . . . . 1.0 3.0 2.0 7.0 11.0 4.0 Oxalate added with constant stirring. . 6.8 3.8 3.0 22.4 16.5 5.0 Oxalate added on sur-face; after 1 5 minutes whole stirred up. . . 3.0 1.0 2.0 11.1 11.1 0.0 Temp. = 20". Water of dilution = 700 C.C. Percentage of 13aCl2 decomposed. 'l'iine = 90 mins.Diff. Time = 24 hours. Diff. /< / . - Roughened beaker . . 24.3 21.7 2% 81.6 -Broken glass in beaker . . . . . . . . . . 7.0 11.0 4.0 7'3.3 -Oxalate added with constant stirring . 22.5 16.5 5.9 $9-3 81.1 1.8 Oxalate added on sur-face; after 15 minutes -- whole stirred u p . . 11.1 11.1 0.0 79.3 -of a wire with a certain weight attached; induction tcnds to rtxuove the weiglit. But the addition of water to the system considered by us tends to increase this weight and so to elongate the wire. Reniow the weight however and the wire suddenly contracts cc OW TIIE COURSE OF CERTAIN CHEBIICAL CHANGES. r l Time = 30 mins. Percentage of BaC12 decomposed. .--./- \ Temp. = 20'. Temp. = SO". Dilution = 800 c.c . 0.0 1.0 , = 700 C.C .3.7 s3.7 (See also curves of Plate VII.j 26. From these results it is apparent that physical differences affect the total amount of chemical change when much water of dilution is pre-sent and the time of action is moderately short (see 700 C.C. 90 minutes). Further that if the amount of dilution-water is made very large the differences between the results obtained become imuiense showing how the action is disturbed by very small alterations i n physical conditions (see 1100 C.C. 5 hours). But that if the time of action be prolonged, the results become tolerably concordant and that those physical con-ditions which were made the subject of examination but slightly affect the final amount of chemical change when that cliange is allowed to proceed f o r prolonged periods even when in exceedingly dilute liquids (see 1100 C.C.28 hours and 700 C.C. 24 1 ~ 0 ~ s ) . Further we conclude from these numbers that if the amount of water of dilution be so large and the time of action be such that but a very small amount of chemical change ensues then the amount of that change is only slightly affected by the changes in physical conditions to which the liquids were subjected in our experiments (see 800 C . C . 90 nz inutes) . The results of Table XI bearing upon the influence of temperature corroborate those of par. 22 viz. that in dilute solutions rise of teni-peratnre largely increases the amount of chemical change the experi-ments made with 800 C.C. of water of dilution however show that if the amount of change a t a moderate temperature be almost nothiiig a rise of temperature scarcely affects the total decomposition. 27. We think that the experiments recorded in the present paper justify our general hypothesis viz. that the amount of chemical change which occurs when barium chloride and potassium oxalate are mixed in the proportion of 1 1 molecules is irregularly affected by variations in the mass of water of dilntion present because the entire system is brought into a state of strain due to the stress between its parts ; and that the principal forces of which this stress is compounded, are the force tending to produce cryohydrate-and other hydrated-molecules the force tending to split up these molecules and the force tending to separate and so to impart greater mobility to the chemi-cally active molecules of the system. The results which we have obtained are it seems to us corrobora 78 MUIR ON THE INFLUESCE OF TEMPERATURE tive of what may be called " the kinetic theory of chemical action," viz. that systems apparenLly stable are continually undergoing atomic interchanges. We have spoken of a system of chemically active molecules as being, under cerhin conditions in a state of strain ; we believe that analogies with this state may be found in supersaturat'ed solutions,* colloidal molecules,? a,nd that " particular condition of bodies in which they are the dkbris of some compound and not proper chemical compounds of their constituents."

ISSN:0368-1645    

DOI:10.1039/CT8803700060

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

78 MUIR ON THE INFLUESCE OF TEMPERATURE KO. IV.-On the Injuonce ?f Temperature q o r z the Decomposition of Buriunz Chloride by Potassium Oxalute in Aqueous Solution. By M. M. PATTISON MUIR. 1. The influence of temperature upon the reaction formulated as-gCaCI + z’Na,C03 = (a-)CaCO:l + rzCaC1 + 2a’-n’NaCl + n’Na2C O:., was considered in outline in the first of these contributions (loc. cit.). The gencral result deducible from the curves of Table G in that paper is that the amount of chemical change in unit time increases as the temperature is varied and this more rapidly with the earlier than with the latter increments of temperature. The initial state of the chemical system in these experiments was approximately CaCl, Na,CO, H20 = 1 1 1,.500 mols. If more concentrated solutions be employed the influence of tem-perature is less marked this is shown by the following numbers :-§ * See especially Tilden “ Theory of Solution &c.,” a lecture delivered to the t “ Liquid J)iff~~sion :ipplied to Analysis.” Phil.Trans. 1861. $ “ On Hydrated Salts and Metallic Feroxides,” by Graham; Brit. ,~S.TOC. 9 The iiuirlbers given are all the means of a t least two closely agreeing experi-Bristol Naturalists’ Society Feh. 1878. Xeports 1834. ments PLATE IX. (TABLE Xm). B a a &C,O,-l:lmolecules. 3Umiautes. -2dihnm d T - e . Harrison k Sons.Lith. S! Martins Lane.W. UPON THE DECOMPOSITION OF BARIUJi CHLORIDE ETC. 79 TARLE XU. 10 C.C. calcium chloride solution used = 320.27 nigrms. CaCI + 8.1 C.C. sodium carbonate sollition = 305.54 mgrms.Na2C03. Initial condition = CaCI Na2C0 H,O = 1 1 330 mols. Each 25 C.C. water added = 470 mols. Time = 10 mins. Mean percentage of CaC12 decomposed. Water added. 7 \ C . ". 20". 56". 80". 50 89.1 89.4 89-6 100 85.5 83.5 88.2 250 83% 89.0 88% Time = 60 mins. 50 91.2 91.4 94.6 100 90.3 91.9 94.2 200 87.9 89-3 L 300 85*2 87.2 -500 72-6 77.6 82.9 Several other series of experiments were carried out with a similar result viz. that temperature exerts little influence on the course of the change except when somewhat dilute solutions are employed and that the influence is then regular. In place of continuing these experiments with much more dilute solutions as was originally intended I determined to examine in a little more detail the influence of temperature on the reaction between barium chloride and potassium oxalate as from the results contained in the preceding paper facts of more general interest miglit reasonably be expected from this study.2. The solutions used and the experimental methods employed were the same as those described in the preceding paper. TABLE XIII. BaCI KZCZO H20 = 1 1 360 mols., Each 100 C.C. water added = 1840 mols. Time = 30 ruins. Mean percentage of BaCl, c.c. water decom~osed. Numbers actually obtained. added. 3'. 20". 80'. 3O. 20°. 80". 100 74.8 79.8 85.0 74.8 - 79.8 - 85.0 -300 31.1 70.8 76.0 50.1 52.2 73.2 68.5 75.7 76.3 600 7.8 8.3 51.1 7.8 - S.9 7.8 52.0 50.3 700 1-0 3.7 33.7 1.0 - 3.7 - 33.7 -Curves A B C and D of Plate TX represent these results i n graphic form TABLE XIV.Mean percentage of BsC12 decomposed. C.C. watei. added. 3'. 20". 50'. 80'. 100 91.6 93.5 95.0 94.8 300 67.8 80.0 88.0 85.9 40C 58.0 65.9 80.4 83.4 500 41.8 4403 63.7 78.7 700 lri.0 20.6 59.0 60.9 800 5.0 4.5 24.2 44.1 900 - 3.1 7.5 42.1 1000 - 5.3 9.6 30.5 BaCl K2C204 H20 = 1 1 3G0 mols. Details as before. Pipetting. Time = 90 Numbers , 3". 20". r - Y-91.6 92.1 91.1 - - 94.5 92.5 67.8 68.4 6'7.2 - - 80.0 80.0 58.0 58.3 57.8 - - 68.7 63.7 41.8 42.8 40.3 - - 42.8 45.8 12.9 16.6 10.2 18.1 17.2 18.6 4.5 5.5 - - - 4.0 3.1 5.3 I - - - -- - - - -Curves h t o H Plate X represent these results graphically P E R C E N T A G E OF C H E M I C A L C H A N G E . td P 8" V UPON THE DECOJIPOSITIOX OF B_lRIUJI CHLORIDE E'FC.81 3. Curves A and 13 (1CO C.C. and 300 C.C. water) confirm the results of the experiments with calcium chloride and sodium carhonate. The iiiflnence of temperature begins to be felt when 300 C.C. matel. of dilution are added ; the increase in tlie amount of chemical change is considerably greater for the rise of temperature from 3" t o 20" than for that from 20" to 80". Bnt when 600 C.C. and 700 C.C. of water are added (Curves C and U), n different result is observed. The increase in the amonnt of chemical change is very small for the first rise of 20" but after that the incream is rapid. These results are I think explicable in terms of the " strain h!ypo-i?iesi.s," developed i n the preceding paper. With tolerably dilute solutions where the formation of cryohFclrate molecules is (by hypo-thesis) small a moderate increase of temperature is accompanied by a considerable increase in the amount of chemical change ; but the sys-tern Iiaving now very nearly reached the point of most stable equili-brium further increase of temperature exerts but little inff iience on the amount of change.If however the contlit'ions favourable to foy-niation of hydrated molecules be maintained-much water and lorn temperature-then a (comparativelJ-) small rise of temperature does not succeed in thoroughly decomposiny the loaded molecules. When, however this decomposition is effected the chemical change proceeds at an accelerated rate i.e. when thc change is fairly started the curves rapidly ascend.It is probable that as the point of maximum stability of the system is approached the influence of temperature on the change would be-come less and less marked in other words the curves would again approach straight lines ; if this were so the curves wonld exhibit points of contrary flexure. 4. Experiments weye now conducted similar to those of Table XIII, except that the time was made 90 minutes (see p. SO). 5. The higher curves of Plate X exhibit t'lie conti%ry flexure re-ferred to in the last paragraph but this again disappears when very dilute solutions are employed. Generally then it max be said that with concentrated solutions, temperature exerts little influence on the amount of the change under consideration with more dilute solutions the first increase of about 20" causes a marked increase in the amount of change but after this influence of temperature is more regular with yet more dilute solu-tions increase of temperature causes a t first a slight increase in tlie amount of chemical action but as the temperature continues to rise, the amount of action rapidly increases until a point is reached after which further increase of temperature but slightsly affects the amount of chemical change and finally that with ?:eq dilute solutions the VOL.XXXTII. 82 MUIR ON THE INFLUENCE OF TEMPERATURE ETC. influence of temperature again becomes nearly regular the points of contrary flexure being higher up in the ciirves and being very much less marked the curvature of the curves being smaller. 6.A few experiments were carried out in order to determine the effect of increasing the mass of one of the reacting substances. TABLE XV. BaClz K,C,O H,O = 1 2 340 mols. Details as before. Pipetfi.i?g. Time = 30 mins. Mean percentage of BaCI, Numbers actidly obtained. added. 3'. 20'. 60". 86". 3". 20'. 50". 80". p- - ,.__ ___- C.C. water decomposed. 800 10.5 16.0 34.0 53.2 l(35 16.0 34.0 34.0 51.4 55.1 1000 2.5 18.0 - 24.0 2.5 19.0 17.0 - 23.0 25.0 7. These results (see Curves A and I3 of Platc XI) show that with 2 mols. potassium oxalate to 1 mol. barium chloride and 800 C.C. water of dilution the effect of increasiug temperature upon the amount of chemical change is iiearly if not altogether regular; but that in a more dilwte solution (1000 C.C.water) the effect is similar to that in much less dilute solutions when equal mols. are used i.e. the first in-crease of 20" causes a much larger increme in the amount of change than either of the succeeding increments of 30". There is however in the Cnrve I3 no indication of contraryflexure, similar Go that of Curves B t o H of Plate X. Let the action be fairly started then the strained condition is so to speak neutralised by the effect of increased mass of potassium oxa-late. 8. These experiments I think present certain points of analogy with the so-called " induct.ion " of Bunsen and Roscoe. We seem to have certain conditions under which the chemical change proceeds a t the normal rate ; but by altering these conditions, the rate of change may be accelerated or diminished. If the condi-tions which diminish the rate of chaiige be somewhat suddenly removed the change may be abnormally accelerated for a time after wbich it may again return to its noriiid rate. The conditions which accelerate o r diminish the sate of change will probably vary for each chemical reaction in the present case, dilution and temperature exert opposing actions on the change con-sidered

ISSN:0368-1645    

DOI:10.1039/CT8803700078

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

83 VII.-On a- nnd p-Pl~e?z.antl~rene-ct-crl)o;e!jlic Acids with Remarks o u tlie Constitution of Plw.nantlwene. By FRAKCIS R. JAPP M.A. Ph.D. Assista,nt in the Chemical Research Laboratory Science Schools South Kensingtou. I HAVE already described ( B e y . 10 1661) in conjunction with Dr. Schultz a phenaathrene-carboxylic acid melting a t 260". I have since prepared this acid in greater quantity and having thus been enabled to purify it more thoroughly find t h a t it melts a t 266". I now pro-pose to designate it as a-phenanthrene-carboxylic acid in order to dis-tinguish i t from the isomeride described for the first time in the present paper. a-Phenant hrene- carboxylic acid was ob tained from crjstallisecl calcium phenanthrene-sulphonate by converting the lather into the sodium salt distilling the dry sodium salt with potassic ferrxpanide, and saponifying the nitrile thus obtained.I n preparing the calciiim phenanthrcae-sulphonate there was always ;t relatively small yield of crystallisable salt and a considerable quan-tity of dark-coloured syrupy mother-liquor. This latter had been f'roin time to time reserved for investigation. As it seemed possible that this mother-liquor might contain an isomeric calcium phenanthrene-sulphonate I determined to subject it to the same processes which had yielded a pheiiantlirene-carbox~-lic acid from the crystallised salt hoping that the corresponding pliena n-threne-carboxylic acid might be more easily purified than the syrupy On adding sodium carbonate until the solution was all ;a I' me a copious precipitate of calcium carbonate was formed denoting the presence of a very soluble calcium salt.The filtered solution of the sodium salt was evapora>ted to dryness and the dried salt was mixed with one and a half times its weight of potassium ferrocpnide and distilled in portions of 100 grams a t a time from a flat copper retort. The nitxile thus obtained was a yellow transparent viscid liquid, which after standing for some days assumed a buttery consistency, probably owing to the presence of regenerated phenanthretie. It mas saponified with alcoholic potash and required boiling for over lot3 hours with inverted condenser before ammonia ceased to be evolved. The alcoliol was then distilled off and the contents of the flask after digesting with water were diluted and filtered.OH acidifj-illg with hydrochloric acid the new acid separated out as a dirty white floccn-lent precipitate. The yield of crude acid from 2 kilos. of coilrmercial phenanthrene x-as only 80 grams, s ulpIlor1 at e . G 8 4 JAPP ON a- AND P-P€IEN_~NTIIRESE-C~~RBOSPLIC ACIDS. The purification of this acid presented considerable difficulties. It dissolved in ammonia yielding a brown liquid. On adcling an excess of barium chloride the barium salt was precipitated carrying witli it, most of the resinous colouring matters. On boiling the barium salt went partly into soluticn yielding a nearly colonrless liquid which was filtered hot from the impurities. The residue had to he repentedly extracted with boiling water as the impnritics enclosed the salt ant1 rendered its solution difficult.Subsequent experience with the barimn salt has shown that a re-peated recrystallisation of this salt would probably have offered it good means of purifying the aci(1 bnt a t this stage the salt did not seem to promise well and its use was abandoned. After a trial of several salts the sodium salt which ~rystallised in long rhomboidal lamin= with a slight satiny lustre mas selected. The snlt was recrys-tallisecl serernl times until it was quite colo~-rrless. On adcling hydro-chloric acid to tile solution /3-yhennnthrene-carboxylic acid was ob-tained as a white flocculent precipitate. 6-Phenanthrene-cnrboxylic acitl is soluble in alcohol ether nncl glacial acetic acid almost insoluble in water. From a hot saturateti acetic acid solution it crj-stallises in stellate groiip of colonrless needles.It sublimes in fern-slinpetl leaves exactly resembling those of t>he a-acid. Analysis yielded the following results :-I. 0.2268 gram gRve 0.6765 gram carbonic anhFclriile and 0.0938 gram water. 11. 0.2837 gram gave 0.8453 gram carbonic anhydride and 0.1151 grain water. It melts a t 250-2552'. Pound. -\-Calculated for CI,KloO2. I. 11. C, . . . . . . . . . . 180 81.08 81.36 81.23 HI . . . . . . . . . . 10 4.50 4.59 4-51 0,. . . . . . . . . . . . s2 14-42 (14.05) (14.26) 222 lu0fw 100.00 100.00 A determination of water of crystallisation and sodium in the sodium s n l t above referred t o g3ve the following results :-0.3782 gram (of a preparation which had been exposed to the air for a long time) lost on heating to 140" 0.0986 gram and the remain-ing 0.2796 gram anhydrous salt when treated with concentrated sul-phuric acid and heated to redness gave 0.0798 gram sodium sulphate.The formula Cl1H,.CO2Na + 5H20 requires 26.96 per cent. H,O. Fouiid 26.07. The forniiila ClpE,.COzNa (anh-ylrous) requires 9-43 per cent. Na. Found 9.25 J A P P OX tl- ,4SD P-PHESASTIIRESE-CXnEOSTLIC ACIDS. 85 The barium salt was obtained as a crystalline precipitate when lmriurn chloride was added t o a solution of the sodium salt. It mas 1)urified by recrystallising from a hot aqueous solution and formed colourleas branched needles w hicli under the microscope appeared as long rectangular laminze. These lamiwe were verj brittle and pos-bessed a cleavage parallel to the right angled terniiristion.Water of crystallisation and barium were deteriniiied with the following re-sults :-I. 0.3763 gram air-dried salt lost on heating to 140" 0-0582 gram, and the remaining 0.3185 gram anh~drous salt gave 0.1276 gram barium sulphate. 11. 0.3185 gram lost on heating to 140" 0.0490 gram and the re-niaiiiiug 0.2695 gram anhydrous salt gave 0.1070 gram barium sulphate. The formula (CI4H,.CO2),Ba + GH,O requires 15.71 per cent. HzO. Found-1. 15.45; 11. 15-38. The formula ( C,,HT,.CO,),Ba (anhydrous) requires 23-66 per cent. Ba. Pound-I. 23.57; 11. 23-& D isti1 ILI t ion of P-l'henail tli retie- c-nrbozy lic Acid with Sodu-1 i me. I K ~ order t o prove that the acid was really a derivative of phenaii-tlirenc 8 grams of the sodium salt were distilled with soda-lime.The phenaiithene thus obtaiiied was identitied by its melting point by that of its picric acid double compound a i d lastly by tliat of the yuiriorie prepared f rcmi it by oxidation. The other physical propertics of these compounds agreed perfectly with those of the phenanthreiie compounds in question. Furthermore t8he quinone dissolved without residue iii a solution of acid sodium sulpliite. OxidutLutL o j p- Pl~e?.ln,ithl.etLe-cu~.~~~~li~ Acid. 1 grain of the acid was oxidised with about twice its weight of chromic anhydride in acetic acid solution. On distilling oB the excess o f acetic acid and diluting with water a substance was precipitated in orange-yvellow needlcs froin which a solution of sodium carbonate extracted R small quantity of unoxidised phennnthrene-carboxylic acid.'l'he residue dissolved almost entirely in a solutisn of acid sodium sul-phite. The pure substance reprecipitutzcl from this solution was cry+ tallised once from glacial acetic acid aid was thus obtained in orange-~ d l o w needles melting a t 204-2U4*5'. (31. p. of yllenanthrene-quinone given by Fittig a t 198" found b j myself 011 a very pure specimen as high as 206O.) Analysis yielded the following results :-0.1924 gram gave 0.566% gram carbonic a n h y d d e and 0.0711 gram l v n t x 86 JAPP ON C( - AND P-PHENANTHRENE-CARBOXPLIC ACIDS. Calculated for CI4HSO2. Found. Cli 168 80.77 80.51 Hs . . . . . . . . . . 8 3.85 4.10 0 . . . . . . . . . .. . 32 15-38 (15-39) 208 100.00 lOC!.OO The substance was therefore pure pheilanthrene-quinone. Tabulated Co?npariso?t oj' a- and P-Phermr th-ene-czcrboxylic Acids. The following table contains the result of a comparison of the two phenanthrene-carboxylic acids and their sodium and barium salts. Most of the crystallographical characteristics here described can he per-ceived only with the aid of a microscope :-A cici. . Sodium salt. . Barium salt u- Acid. ~~~ Crystallises from hot glilcid acetic acid in colourless curved blades with pamllel edges and a rectangular termination. This currature is very characteristic. Sublimes in fern-shaped leares. M. p. 266". (The melting point 260O was given in the first p p e r . ) of colourless pointed blades.100 parts of water at 20" dis-solves 6.8 parts of the anhydrous salt. Almost indefinitely sdu-ble in boiling water. C(IIHS.C(OQNa + 4H20. Tufts (C14110CO~),Ba + '/H,O. Colour-less long needless of eutraoidi-nary fineness mid flexibility, radiating from one point to form large balls or tufts. Under the microscope .a t a n g l d mass of these flexible needles has the appearance of vegetable fibre. 100 parts of water clissolve-p-Acid. Crptallises from hot glacid acetic acid in sttellate groups of colourless st8i*aiglit pointcd needles. S nblimes in fern-shaped leares. 31. p. 250-252O. C,lIf~.CO,Pu'a + 5&0. Colour-less rhoinboidal laminq with a slightlg satiny lustre. 100 parts of water a t 20" dissolve 6.2 parts of the anhydrous salt.Almost indefinitely soluble in boiling water. (C,JI,.CO,)nBa + GH,O. Co-loarless long brittle rect:m-gulsr Isminre united in a rami-form erystallisntion. 100 parts of water dissohe-At 20'. . -27 parts of anhy-, 100" 3.70) drous salt. !K% eoretical Considerations. It has been shown (Jappand Schultz loc. tit.) that a-phenanthrene-carboxylic acid yields on oxidation phenant hrene-quinone-carboxg lie acid the carboxyl group remaining intact and that a-phennnthrene-ca,rboxylic acid has therefore the formula JAPP 0s Z- ASD P-PI-IE-U-4~'THRESE-C:1RI305YLIC ACIDS. 87 C0.OH I C,H,-CH, 1 II C,H,-CH the exact position of the carboxyl group in the benzene nucleus re-maining undetermined. A phenanthrene-carboxylic acid 117 hich on oxidation yields plienan-threne-quinone with elimination of the carboxyl group must contRin tlhis group attached to one of those carbon atoms which in the quinone are united with quinonic oxygen.This would give-C,H C- C 0. OH CGHA-CH I I1 as the constitutional formda of P-phemnthrene-carboxylic acid,* and-C,HA-C-SO,.OH as the formula of the sulphonic acid from which i t is derived sup-posing no migration of atoms within the molecule to have taken place during the distillation with potassic ferrocya,nide.+ The formation of this sulphonic acid by the direct action oficon-centrated sulphuric acid on phenanthrene seems to me to cast fresh light on the constitution of phenanthrene and indirect,ly on that of the benzene nucleus. The graphic formula of phenanthrene expressed in terms of KekulA's benzene theory is-* Licbernianii and rom Rath (Ber.8,248) seem to hare observed the pesence of tliis acid as an impurity in their anthracene-carboqlic acid. They mention that 8 specimen of the latter acid prepared from impure nnthrxcene yielded on oxidation, in addition to anthraquinone-carboxylic acid phenanthene-quinone. -t As this point was of importance the following experiment ~ v a s undertaken to decide it :-A portion of the very soluble sodiuni phenanthrene-swlplionate from which the P-phenanthrene-carboxjlic acid H'BS prepared was dissolved in water anJ oxiclised with a mixture of potassium clichromatc and sulphuric acid. Carboni 8 8 JAPP ON U- AXD P-PHE~X~THRESE-C~RCOSTL~C ACIDS. a plain hexagon being employed t o sFmbolise the benzene nucleus iri ordcr to avoid introducing the conip1ic;Ltcd question of alternate double and single bonds t o which LoweT-cr reference will be made further on.Grnebe’s synthesis of this compound from stilbene-symnietrical cliphenyl-ethylene-shows it to be diplienylene-ethylene. Schultz ( B e r . , 111 215) on the one Iiand and Anscliuetz and Japp (ihid. 11 211), ( a i l the other showed by two iridepeiiclent methods that phenanthrene is a diortho-compound arid that i t must therefore be regarded as symmetrical dioytho-dipheuyleire-etliFlene as expressed in the above graphic formula. Many of the chemical reactions of phcnantLrerie seem to indicate that the dyad ethylene residue -CH=CH- i n tlic diphenylene-utliylcne forms pait of an aromatic nucleus.On oxidation the two atonis of hydrogen are replaced by two atoms of oxygen (not by one), a quiuone being formed. This quinone 011 reduction yields a hydro-quinone containing the group -C (OH)=C( OH)- and dissolving in caustic alkalis by virtue of these plicnylic hydroxyl groups. Mono-bromphenanthrene in which the s u h t itution of bromine takes place in the -CH=CH- group-tlie coniponnd yielding on oxidation phenanthrcne-quinone tvitli elirriiiiatioii of the bromine atom-may as Aiischuetz has shown (BcI-. 31 1217) be heated with strong alcoholic potash to 170” without undwgoirig change. Aiiscliuetx points out the bearings of this fact and the importance of a proof of the aromatic chaiacter of this portion of the phenanthrene molecule. Indeed, hen one considers tlie relatire mobility of the bromine atom i n monobromctbylene and mono~~urnstilberle lien these compounds are lreatcd with alcoholic potash this stability of rnouobromplienaiithreiie innst be allowed to furnish very strong cvitlence that the group - - C H ~ C H - forms part of an aroinatic iiucleus.A fresh picce of evidence of a similar cliaimAer may be found in the :ibove-described direct formation froni pLenniitbrene atid sulpburic mid of a sulplio!iic acid in whieli tlie sulyholiic group replaces one of the hydrogen atoms of the - - C H ~ C H - group. A direct snlphoiiation of a liyclroc~arbon has as yet h e n observed only in the ttroniatic nucleus. I n the fatt)y series the presencc of an elcctro-nega-tivc grmp (CN CO.OII &c.) is necessary in order that direct sul-1)hoiiation may take place.r i 1 licse reactioiis are without exception spccificaliy aromatic in anhydride 11 as e%oivctl niid n n or:iiigt.-j t.110~ precipitate I\ as formcd ~vliich after 1:urifjing in the uiaiincr already desct ibcd (see “ Osidatioil of P-I’henantlireiie-earbox>lic Acid,” 1). S;) crj stalliscd in ~ieedloa fusing betwrcri 198‘ and 200° and exhibiting all the other proprties of ~)licii:~ritlireiie-q~~ixi~xi~~. The presence of’ a I’~ienantlireiic-sulplioiiic acid of the a h \ e forriiulil as t1iu.i proved character and taken together form a strong cumulative proof t h a t the -CHECH- group belongs to a hcnzerie nucleus. In the synthesis of pliensiithrene from’ syminctrical diphenyl-ethj-lene we have therefore constructed a benzene nucleus from the ctliplene residue -CHXCH- on the one hand (which as long as i t l>xisted in diphenyl-ethylene showed by its e:itire behavionr that it (lid not belong to a benzene nucleus) and on tlie other two pairs of (.arkion atoms each of whicli pairs WRS contained i n the ortho- position I)y a separate already existing nucleus :-C / c II I - CH II CH I c I’iienantllrene therefore collsists 02 three Leiizene nuclei one of which shares f o u r adjacent carbon atoms wit11 the two others-one ortho-pair with each.Phenanthrene niay thus be derived from lmphthalene by a repetition of the process by wliich thc latter hydro-carbon is derived from benzene-a suggestion thrown out by Graebe ( A m . C l ~ e n ~ . P J i a ~ i i ~ . 167 133) in his memoir on plieuant>hrene.The portion of tlie liydrocarbon to the right o€ thc dotted line i n tlie above graphic formula is the dyad group to which reference has been iuatle. Ldenburg has shown (T‘lLcui-ie der amuatischeii V w b i t d u ? L g e i ~ ) that c d j 1wo graphic formula satisfy the coriditioris required by a benzcne i~ucleus-his own “ prismatic ” formula aid Kekulh’s hexagon with alternate double and single boiids or wliat is practically identical witli this latter Lothar hleyer’s rriodified Kekul&’s liexagon wit11 six free afinitics. I f the central nucleus in phenanthrene is a benzene ~~ucleus then Ladenburg’s prism must be abandoned as i t is impos-bible to arrange three such prisms with four carbon atoms in tlie ortho-pof,ition in common so as to uatisfy the conditions required by t be phensiitlii-ene formula.* 1 It is equal!! iiupossihle t o express tlie naphthalene formula byr iiieans of Laden 90 EEDSON ON SOME DERIVATlVES OF As regards the formerly much vexed question of altcriiate double and single bonds in the benzene nucleus and whether the ortlio-com-pounds 1 2 and 1 6 ough% on such ft supposition to he identical, this difficulty could perhaps be best avoided by the adoption of Lothar Meyer’s hexagon with six free affinities.Carried to its logical conclusion this w o a l ~ l lead t o the universal substitution of free nEini-ties for double bonds as has been done before now. As long as wc have no physical conception of what a bond is this would involve no contradiction. All that a double bond represents is the potentiality of taking up two monad atoms or groups arid this is equally well accounted for by the assumption of free affinities. It is strange that in an opcn chain a double bond should represent the weakest part of the chain. A final proof of the aromatic nature of the central nucleus of pheiianthrene would be the preparation of naphtbalene o r one of its derivatives from this hydrocarbon. Experiments which I have made in this direction have as yet failed owing to the oxidisable character of the central group which causes it to be attacked sooner than the lateral nuclei even when the hydrogen atoms of one of the latter have been replaced by liydsoxyl groups in order to render the nncleus less stable. I t is evident from the graphic formula that five mono-substitution compounds of plienanthrene are theoretically possible

ISSN:0368-1645    

DOI:10.1039/CT8803700083

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

90 EEDSON ON SOME DERIVATlVES OF V111.- Ox some Derivcdiues of Plmiylacetic Acid. By P. PHILLIPS B EDSON D.Sc. Assistant Lecturer and Demonstrator in Chemistry a t the Owens College. FOE our knowledge of the derivatives of phenylacetic acid we arc: chiefly indebted t o Radziszewski (Bet-. 2 207) who first investigated the conditions under which substitution may take place either in the aromatic nucleus or in the side-chain. My investigation of some of the derivatives of this acid has led to results differing somewhat from those of t h e above-mentioned chemist. I here propose to give an account of these results together wit,h some further particulars rela-tive to the bromonitrophenylacetic acids &c. the study of which I undertook whilst in Bonn a t the proposal of Professor Kekule ant1 burg’s prism but Ladenburg throws doubts on Gmcbc’s proof of the sjmmetri-cal character of naphthalene PHEXYLACETIC ACID.91 short notices of which have already appeared in anotller Journal ( R e r 10 530 and 16.57). Nitro-del.ivativ~s.-Phenylacetic acid when nitrated yields two iso-meric nitro-derivatives viz. the para- and the ortho- the former constituting the chief portion of the yield. The method of separating these two acids by the different solubilities of their barium salts does not give satisfactory results. If however tlhe acid prepared from the less soluble salt be crystallised repeatedly from a hot mixture of alco-hol and water an acid is obtirinecl crystallising in long needles, and melting a t 150-151" wliich proves t o be paranitrophenylacetic acid.(1.) PnrnnitropheiiyZncetic a c i d is soluble in hot water from which it crystallises in long yellowish-white brittle needles ; it is sparingly soluble in cold water and easily in alcohol and ether. Its analyses gave the following results :-I. 0.3066 gram yielded 0.5978 gram COz and 0.1109 gram H,O. 11. The " NOz " was determined by Limpricht's method (Uer. 11, 35) 10 C.C. of stannous chloride solution diluted to 250 C.C. gave a solution 10 C.C. of which required 10.83 C.C. of iodine solution. 1 C.C. of iodine solution contained 0.01108 gram I = 0.000667 gram NO?. 0.2132 gram of acid heated with 10 C.C. SnCIz solution diluted to 250 c.c. gave a solution 10 C.C. of which required 7-64 C.C. of iodine. 25 X (10.83 - 7-63) x 0.000667 = 0.005336 gram KO2, Found.I. 11. C - = 96 53.03 52-16 HY . . . . . . . . - 7 3-86 4-01 NO = 46 25.41 - 25.0.2 - -- - 0 . . . . . . . . = 32 17.67 - -___ 181 100*00 This acid when oxidised by a mixture of potassium bichromate and sulphuric acid yielded paranitrobenzoic acid m. p. 230" ; the combus-tion of which gave the following numbers :-0 3064 gram yielded 0.5682 gram COz and 0.088 gram H,O. Calculated for C6 ff jNO,CO,H. Found. C 50.29 50.52 H . . . . . . . . . . 2-39 3-16 Methyl purni7it,.o~heiL~7acetnte C,Hf,.P\T0,.CH2C0,CH3 crjstallises from alcohol in yellowish-white plates by slow evaporatioii of the aIcohoIic solution it is obtained in thick striated plates ; it melts a t 54-55" 92 EEDSOS OX SOME DERIT'ATIVES OF Ethyl paranitrvplieuSlacctat~ crystallises from dilutc alcohol i n thin, shiiiiig leaflets nieltiiig at 62-6 i'.Tlic Z ~ l n r i z ~ ? ~ ~ suZf is obtained in I;reautiful light ello ow transparent (.i*,vstds bj- allowing the aqucoiis solution to cvaporate slowly. These (*rystals apim~r to be six-sided plates ; as o n exposure to s i r they c~rffortwe and bec'ome opaque their esact crj-stalline form could not be tl9xxmiinerl. Tlie crystals quickly dried between filter-paper gave results (I) corresponding t o t h e formula 13a(CsT-I,N0~)~ + 7HZO ; v hilst tlie air-dried opaque crystals gave results (11) for the formula I. 0-5358 gram heated at l l O - l l . ~ o l o s t 0,113 gram and gave lh(CJ1&OJL + 2&0. 0.1951 grain 13uS01. Cdcnlatcd for IJa(C'*H~ZCo,)> + m'J0.Found. 1h . . . . . . . . . . 21.99 2 1-45 11,o. . . . . . . . . . 20.22 21.08 11. 0.2912 gram heated at 10G--11Oo lost 0.0214 gmm and gave ci.i28S gram BaS04. Calculated for 13a(c&To4)2 + 21120 Found. Ih 2 5 . i O 25 92 lI,O . . . . . . . . 6 . i 5 7-34 The arlwoiis solution of thc barium salt gives with lead acetate wlutim a wliitc precipitate which partially dissolves wheii boiled and ~~ec~ybtallises on coo;iiig ; with silver nitrate solution a while curdy 1)recipitate soluble in aiumotiia and nitric acid arid firially with ferric chloride a brownish precipita:e. duction of the psranitro acid by tin and hjdrochloric acid ; it crystnl-libes from Lot aqueous solutions in white lustrous leaflcts which 1,econie brown on exposure to air and melt s t 199-200" with decom-Imiition.Ylic analysis of this acid gave the following numbers :-0 2 3 3 i gram gave 0.5432 gmm C 0 2 and 0.129 grain water. I;on lld. c,. . . . . . . . 96 G2.57 63.08 H . . . . . . I 5-96 6.06 N . . . . . . . . 14 0.27 -0,. . . . . . . . 32 21-20 - - -151 100.00 ( 2 . ) O,-tl~ci.iiit,.o~l~e?l~Zacetic acid. - The alcoholic mo tlier-liquors €ro1:1 tlie crjstallisatiori of the Paranitl.o-d~riv~tive wlicn conceiitrate PIIENTLACETIC ACin. 93 yield a body crystallising in white opaque tufts of needles melting. it'' 112 -117'. A similar product is ohtained by decomposing the niorck soluble barium salt with hydrocliloric ncicl. By allowing the solntion of this body in inethSl or ethyl alcohol to evnpomte slowly large well-formed crystals separate out yliich were collcctcil and recrystallised from alcohol.By this means a fcw grams of thcse crystals wero obtained melting a t 137-133". When crystnllisecl from hot water, in which they arc sparingly soluble white shininq needles sepnrntc out at first and on standiny minute crystals appear having n form similar to the lnrqer oms. Coth the needles and the minute crgstals melt a t 137-138". The combustion of the acid crystallised from water gave the follow-ing results :-0.302 gram Sielded 0.585 'gram CO and 0.11% gram H,O. Calculated for C,FTZ;ZCO2H. Foun (1. c $3.03 52-64 H . . . . . . . . 3-86 4-13 This acid when oxidised by boiling with n solution of potassium permangannte yields orthonitrobenzoic acid subliming i n white needles and melting a t 141-143O.Moreover upon redaction i t is converted into osindol which was recognisccl by its melting point, 120° and its reaction with nitrous acid. From these facts I concluclc that the second nitro- acid in. p. 137 -188" is ol.tlionit7.o~lien~~~cetic ccrid. For the following description and ineasurcments of the crystals of orthonitrophenylncctic acid I am i n d e b t d to Mi Baker. Orth on 2roph englncetic Acid. Monoclinic. Fig. 1. OP + I' mPcn ; tabiilar thro-rigli OP. , 2. OP + P c&m in eqnilibrinrn together with 0312,). c i K c = 1.0 0.5%; L = 9 7 O li'. . Found. Calculated. OP +P = 51" 45' 51" 4.")' mPm + P . . = 108 9 108 13 OP 03Pm = 97 1 7 97 1 7 +P +I' (in clino-diagonal) . . . . = 94 28 94 2s mP2 cnF2 (in ortho-diagonal) .. . . = 81 lt; 81 ( 9.2 EEDSON ON SOME DERIVATIVES O F Barium orthonitrophenylacetate crystallises from its aqueous solu-tions in white lustrous scales which are more easily soluble in water than the crystals of the corresponding salt of the para-acid. The analysis of this salt shows its formula to be BR(C,&NO~)~ + 2H20 ; the water cannot be directly determined as the salt is decomposed at 100-110". 0.495 gram gave 0.2121 gram BaS04 i.e. 2.5.17 per cent. Ba wliilst Ba(C,H,NO,)? -+ 2H,O requires 25.70 per cent. Ba. Aqueous solutions of this barium salt give no immediate precipitate with s,lution of lead acetate; on standing however the lead salt separates out in tufts of fine needles. Silver nitrate and ferric chloride give reactions similar t o those with the solutions of the salt of the para-acid .( 3. ) Rnmo- c7ey iv n lives .-B ro mo ph en y 1 acetic ac id was prep are d by an application of Barth and Weselky's method for such cases viz. by treating plienylacctic acid and mercuric oxide suspended in water, with the calculated quantity of bromine in small quantities a t the same time cooling by immersion in water. The reaction which takes place is expressed by the following equation :-2C7H7C02H + HgO + 2Br2 = 2C7H6Brco2H + HgBr2 + 2H20. After the completion of the reaction an excess of caustic soda is added and the filtrate from the mercuric oxide acidified with hydro-chloric acid ; the bromo-acid separates out as a white crystalline pre-cipitate and after washing with cold water is crystallised from hot dilute alcohol.The chief portion separates ont from this solution as a slightly colourcd oil which on standing soIidifies to a crystalline mass; some also crystallises out in tufts OF white needles both por-tions melting at 76". The alcoholic mother-li ynors on concentration jield an acid having a somewhat higher melting point. This latter portion is converted into the barium salt either by boiling its aqueous solution with barium carbonate or with baryta-water aiid in urhich ease the excess of barium is removed by precipitation with carbonic :xcid. The concentrated aqueous solutions of this salt yield a white crystalline deposit formed of opaque nodular masses ; these deposits were crystnllised from hot water and finally decomposed by hydro-chloric acid.Pacrabro??zoz~hen2JZacetic Acid.-The acid thus obtained is dissolved in hot water from which solution il separates on cooling in long flat lustrous needles resembling the crystals of benzoic acid and melting a t 114-115". I t s analysis shows it to be a monobromophenylacetic acid and its melting point is the same as the parabromol?llen~Iacetic acid prepared by Loring Jackson and W. Lowery (Bey. 10 1210) from parabronibenzyl bromide PHENPLACETIC ACID. 95 The analysis gave the followiiig results :-I. 0.256 gram gave 0.4188 gram C02 and 0.0786 gram H,O. 11. 0.23136 gram gave 0.198 gram AgBr and O.CO65 gram Ag. Found. I. IT. C,. . . . . . . . . . = 96 44.65 44.GO -H; . . . . . . . . = 7 3.25 3.39 -Br . . . . . . . . = 80 37.20 __ 37.14 - - 0,.. . . . . . . . . 64 17-90 247 100.00 -O ~ t l r o b ~ o ~ n o ~ l i ~ ~ ~ ~ ~ l a c e t i c Acid.-The mother-liquors coctaiuing the mere soluble barium salt which on further evaporation Iield no crystalline deposit, were precipitated with a solution of lend awtate, and the white precipitate so formed d t e r mashing with cold water was boiled with dilute sulphuric acid. The filtrate from tlie lead sulphate OIL cooling yielded crystals of an acid which after several crystal-]isations from hot water is cbtained in tlie form of long lustrous flat needles melting a t 103-104" the analysis of which gave the follow-ing results :-I. 0.2104 gram gave 0.8436 gram C 0 2 and 0*0.%4 gram H,@. 11. 0.257 gram gave 0.2148 gram AgBr and 0.0066 gram Ag. Found. Calculated.I. Ir. C . . . . . . . . . . . . 44.65 44.33 -H i . . . . . . . . . . . . 3-25 3.04 -o* . . . . . . . . . . . . 17-90 100~00 Br . . . . . . . . . . . . 37.20 - :ji.43 - --These results together with the fact that when this acid is oxidised hy boiling with a solution of potassium permanganate orthobromo-bellzoic acid is formed melting at 143-144" prove this acid to bt: orthobromophenylacetic acid. The orthobromobenzoic acid gave the following results for the bromine determination ; 0.1932 gram gave 0.1754 gram AgBr and 0.0027 gram Ag giving 39.24 per cent. Br, whereas the formiila CGH,< C02H requires 39.83 per cent. Br. Orthobromplie~iylacetic mid may be obtained in well-formed crys-tals by the slow evaporation of its solution in glacid acetic acid for the following description of which I am indebted to 31r.Baker :-H 9 ci BEDSOS O S SOJlE DERIVATIVES O P 0 rt /LO Z 1.0 nip 7 e ) I y 7n c e t i c it c id. System monoclinic ti 6 1 = 1.000 0.657 1.767; L = XI" 44 . Forms obscrvecl WP . OP . mP00 . Roo . +Pm. . -P. Calciilat rd. Foi 1111 1. mP COP (in ortho-tlingonal) . . . . 112" ;;i' 112" 2i' . . . . . . . . . . . . . . . . OP mP-00 (L) 99 44 99 44 UP =+P ca . . . . . . . . . . . . . . . . 142 51 142 4C: COP -I' . . . . . . . . . . - . . . . . . . . . 163 6 163 1 5 UP %W . . . . . . . . . . . . . . . . . . . . 110 40 110 5-1. OP COP C?5 23 95 2-c From the ahovc experiments bromine in the cold acts on phenyl-acetic acid in a similar mamer to nitric acid producing para- 2nd ortho-derivatives in each case the melting point of the " para " is about 13" higher than that of the " ortho." Furtlier these results show that the parabromphenylacetic acid described by Radziszewski (Zoc.cit.) melting a t 76" is a mixture of the two isoiiierides. A similar remark may be made with regard to the para- and ortho-nitro-phenylacetic acids clescrihed by the same chemist the former melting a t 114" and the latter a t 98". In one of the recent numbers of the Be7.7i7ze~ Bericlite (12 17'64), Maxwell publishes a description of paranitrophen3.lncetic acid to which he attributes the melting point 151*.5-1.52" which agrees toler-ably Tell with my determinatioc as does the description of the methyl- and ethyl-ethers of this acid. The barium saltis described as anhydrous and ergstallising in needles a difference probably due to the method of preparation.(4,) Bihi.omo-Jcl.;v~tives.-To prepare a bibronio-acid crude bromo-phenylacetic acid (m. p. 5G") was sealed up in a strong glass vessel with the calculated qnantitp of bromine and exposed for several niontlis to the action of sunlight. Thus a brownish liquid was pro-duced and on opening the vcsscl quantities of hydrobromic acid were given off. The product after mashing several times with water, was converted into the methpl-ether xs all attempts to obtain a crys-talline product by crystallisation from alcohol had proved futile, yielding n yellowish viscous mass only. The methyl-ether when dis-tilled under reduced pressure chiefly came over at 220-230' ; thi PHENYLACETIC ACID.47 portion was saponified by boiling with caustic potash. The potassium salt decomposed with hydrochloric acid and an acid obtained which crystallises from water in white shining needles melting a t 114-115". But a small quantity of this acid was obtained ; the bromine deter-mination shows it to be ;L bibromophenylacetic acid. 0.276 gram gave 0,3521 gram AgBr and 0.0022 gram Ag which corresponds to 54-78 per cent. Br whilst C,H,Br,CH,CO,H requires 58-42 per cent. Br. Together with this acid other acids are formed but in quantities nsufficient for analysis. (5.) Broi,ioi~itl.o-derivatl:ves.-Short notices of the preparation and separation of two bromonitrophenylacetic acids and the corresponding hromamido-derivatives have already appeared (Ber. 10 530 and 1637).The following is a more detailed account of these acids and also of a third isomeride. As in the preparation of these acids I used a bromophenylacetic-acid melting at 76" the formation of three bromonitro-acids is not astonishing as the bromo-acid contained both the para- and ortho-derivatives ; it renders doubtful however the constitution attributed to the bromonitrophenylacetic acid melting a t 167-169". 3 0 , Parabromorn etanitrophen. y lace tic acid C B,' R r crptallises 'CH,CO,, from its hot aqueous solutions in small flat greenish-yellow needles, melting at 113-114". It dissolves in hot water but is almost in-soluble in cold water and is easily soluble in alcohol and ether. The analysis of this acid gare the following results :-I.0,3005 gram gave 0.4076 gram CO and 0.0735 gram H20. 11. 0.252 gram gave 0.1736 gram AgBr and 0.0055 gram Ag. 111. The " NO " determination was made by Limpricht's method, 0.2123 gram gave 0.036768 gram NO,. Found. I 11. 111. < '-- - C8 56 36.92 36.97 H - - 6 2.30 2.66 NOz . . . . 46 17-68 .- - 17-31 Br . . . . . . 80 30.76 - 30.90 -0 2 32 13-34 - - -260 100.00 This acid when oxidised by potassium bichromate and sulphuric acid yields parabromometsnitrobenzoic acid melting at 197-199", described by Hiibner Ohly and PhiIipp (Liebig's dnnaben 143 248). Its analysis gave the following results :-YOL. XXXVIT. 98 BEDSON ON SOME DERIVATIVES OF I . 0.2675 gz:am gave 0.3391 gram CO and 0.05485 gram H,O. 11. 0.289 gram gave 0.3635 gram CO and 0.0577 gram H,O.111. 0.3 gram gave 0.221 gram AgBr and 0.0057 gram Ag. Found. 11 I. I I. Ill' c , - - 84 34.14 34.54 34.29 -H . . . . . . - - 4 1-62 2.23 2.21 -N . . . . . . - 14 5.69 64 26.03 0 4 . . . . . . -246 100~00 - - -_ - -BY - 80 39-52 - - 32.7:3 - - - -- -__ Barium parabromometani trophenylacetate Ba( C,H,BrNOa) + H20, crystallises in yellowish plates or needles united in concentric groups is soluble in waker but less soluble than the salt of the 2-bromitro-acid. The ana,lpsis of this salt gave the following results : 0.569 gram heated a t 110-120" lost 0.154 gram and gave 0.1969 gram BaS04 corresponding to 2.70 per cent. H,O and 20.33 per cent. Ba whilst the formula requires 2.79 per cent. H,O and 20.35 per cent. Ra. A dilute solution of the barium salt gives with silver nitrate a white curdy precipitate soluble in nitric acid with copper acetate a bright blue precipitate and witth lead acetate a white precipitate, which dissolves on boiling.The methyl ether forms yellowish-white needles usually grouped together melting a t 40-41". Its ethyl ether has only been obtained as an oily liquid. NH, Para~rornometamidop~en~jlacetic m i d C,H,/Rr olhined by the rediiction of the nitro-acid with tin and hydrochloric acid crystal-lises from water in white silky needles which colour slowly on ex-posiire t n the air. It is less soluble in water than the a-bromamido-acid but is easily soluble in alcohol and chloroform and sparingly in ether. It melts a t 133-134'. I t s analysis gave the following result :-0.2156 gram gave 0.3315 gram CO and 0.0714 gram H,O.\CH?CO,H Calculated for C6H,NH,.Br.CH2C0,H. Found. C 41.73 41.92 H 3.47 3.66 Its hydrochlorate C,H,BrNCO2H.HC1 + H,O crystallises in whit PHESPLACETIC ACID. 99 needles united in concent.ric groups becoming red on exposure t o the air. It is soluble in cold water. The analysis of this salt gave the following results* :-I. 0.2636 gram gave 0.1282 gram AgCl and 0.0041 gram Ag. 11. 0-2208 gram gave 0.275 gram CO and 0.084 gram H,O. 111. 0.333 gram gave 0.2168 gram of AgBr. Found. Calculated. I. 11. 111. C . . - 33.96 - . . . . . . . . . . . . 33.72 - 4.21 - H 3-86 Br 28.12 - - 27.68 C1 . . . . . . . . . . . . 12.47 12.51 - -a-BI.o.l~zo1Lit)"@~~?~e?L~lacetic acid crystall ises from water in yellowish-white branching needles melting at 167-169'.It is easily soluble in alcohol and ether is insoluble in cold water but soluble in hot water, and less soluble in a mixture of alcohol and water than the isomeric acid already described. The following are the results of its analy-s1s :-I . 0.303 gram yielded 0.4106 gram CO and 0.0776 gram H20. 11. 0.5884 gram yielded 0.7955 gram CO and 0.1354 gram H20. 111. 0.5335 gram yielded 0.3861 gram AgBr and 0.004 gram Ag. IV. 0.2172 gram by Limpricht's method gives 0.037852 gram (' NO,." Found. c - Calculated. I. 11. In. IV. C . . - . . . . . . . . . . 36.92 36.93 36.86 -H - . . . . . . . . . . 2.30 2.83 2.54 -31.32 - Br . . . . . . . . . . 30.76 NO,. - . . . . . . . . . 17.68 0 . . . . . . .. . . 13.34 - -- - 17-42 - - - -100~00 The barium salt Ba(C8H,BrN04)2 + 4H,O forms yellow transpa-rent needles united to form concentzic groups is soluble in hot water, less solubfe in cold and more soluble khan the salt of the isomeride already described. The following results confirm the above formula : -0.4718 gram heated at 110-115" lost 0.046 gram and gave * I n I tphe chlorine waB determined by adding silver nitrate to the aqueous solu-tion of the hydrochlorate ; in 111 the substance heated with lime &c. gave a mix-ture of silver chloride and bromide and the amount of the lat,ter determined by sub-tracting the silver c'hloride given by the chlorine determination. H 100 BEDSOS OX SOMI3 DERIVATIT'ES OF 0.1501 gram BaS04 ; or 9.74 per cent. H,O and 18.69 per cent.Ba the formula requiring 9.99 per cent. H20 and 18.84 per cent. Ba. The aqueous solutions of the barium give with silver nitrate and lead acetate solution similar reactions to those of the isomeric acid ; copper acetate however gives a green precipitate. The methyl-ether forms transparent slightly yellow flat shining needles; it melts a t 66-68". The ethyl-ether forms yellowish needles. a-BromaImidophelz?tlacelic acid is obtained by reducing the corre-sponding a-nitro-acid with tin and hydrochloric acid ; it crystallises from Kater in white brittle needles which redden.on exposure to the air and melt a t 167" a decomposition taking place at the same time. It is soluble in alcohol and chloroform but sparingly soluble in ether. Its analysis gave the following results :-I.0.2006 gram gave 0.3055 gram CO and 0.0684 gram HZO. 11. 0.2276 gram gave 0.1692 gram AgBr and 0.0099 gram Ag. Found. - CalcuIated. I. 11. C . . . . . . . . . . . . 41.73 41.52 -H . . . . . . . . . . . . 3.47 3.78 -Br 34.78 - 34-88 The hydrochlorate of a-bromamidophenylacstic acid, C8H,BrN02HC1 + H20, crystallises from water in long white needles which become red on exposure to the air ; it is more soluble in water than the hydrochlorate of the isomeric acid already described. Its analysis gave the following results :-I. 0.2404 gram gave 0.302 gram CO and 0.0892 gram H,O. 11. 0.220 gram gave 0.1065 gram AgCl and 0.0034 gram Ag. 111. 0.2029 gram gave 0.1319 gram AgBr. IV. 0.9059 gram heated in a current of dry air at 90-100" lost 0.0574 gram.' Calculated for Found .CGH3Br.NH2CH2CO2H.HC1 + 7 -_1___7 H,O. I. 11. 1x1. IV. 34.23 - - - c 33.74 H 3.86 4.11 - - -27.64 - Br 28.12 C1 12.4'7 - 12.45 -H20 6.32 - --6.35 - - I The salts of t'his acid with the alkalis are easily soluble in water PHENYLACETIC ACID. 101 their solutions give a dark green precipitate with copper acetate of tlie copper salt. /3-Brornonitrophenylacetic Acid.-Together with the above two bromo-nitrophenylacetic acids a third is formed ; it was separated from the yellow crystalline mass obtained by extracting with chloroform the mother-liquors from the nitration of the bromophenylacetic acid. This extract was dissolved in glacial acetic acid and the solution allowed to evaporate slowly thus an acid was obtained crystallising in small transparent yellow prisms.It melts a t 162" and when crystallised from hot water it forms long colourless needles having the same melting point. By reduction with tin and hydrochloric acid, it is converted into a bromamidophenylacetic acid which crystallises from water in white leaflets becoming brown on exposure to the air ; it melts at 186". Its hydrochlorate is less soluble in water than that of either of the above isomerides. But a small quantity of these two acids has been obtained ; the analysis of the bromamido-acid gave the following results :-I. 0.213 gram yielded 0.324 gram CO and 0.072 gram H,O. 11. 0.2385 gram gave 0.1821 gram AgBr and 0.0061 gram Ag. Found. Calculated ioi. r h \ C,IIB.13r.NHf.CiI,C0,H I. I r. - C . . . . . . . . . . . . 41-7s 41-45 H . . . . . . . . . . 3.47 3 . i 5 Br . . . . . . . . . . 34.78 - ;;$*2'3 -From the parabromomctamidophenylacetic acid and the a- brom-amidlo-acid I have attempted to obtain the amidophenylncetic acids by means of tlie action of sodium amalgam on tlie aqueous solutions of these acids ; the results of this action are however not very satisfac-tory. Some further clue to the constitution of the above bromonitro-phenyl acet,ic acids I hope to obtain by the preparation of the nitro-paramidophenj lacetic acids and from which by means of the diazo reaction t o prepare the corresponding br~inonil~o-deriv~ttIvcs

ISSN:0368-1645    

DOI:10.1039/CT8803700090

出版商:RSC    

年代:1880

数据来源: RSC

摘要:

102 IX.- On the Xpecijic Volume of ?Vuter of CyysLallistx.tion. By T. E. TEORPE F.R.S. and JOHN I. WATTS. PLAYFAIR and JOULE have pointed ont that the volumes of certain highly hydrated salts e.g. sodium carbonate with 10 mols. of water, and the alkaline arsenates and phosphates with 12 mols. are exactly equal to that of the water considered as ice which they respectively contain. The molecules of the salt proper would thus seem to exist in the interstitial spaces of the ice since they exert no appareut in-fluence on the bulk. I n many of these as for example borax with 5 mols. of water sodium pyro-phosphate and normal aluminium sulphate the volume seems to be made up of the water considered as ice together with that of the base as existing in the free state. Schiff some years since showed that the members of certain classes of hydrated salts have practically the same specific volume.Thus all the alums have a specific volume of about 277 ; double sulphates of the form M,.M"( SO,),SHi,O have a common volume of 207 ; arid all the vitriols that is the salts o l the form M"S04.7H20 whether isomor-phous or not have the specific volume 146. It is of course well known that many salts can unite with water in different proportions to form perfectly dcfinite combinations. Thus, according to various authorities i t is possible to obtain ferrous sulphate combined a t ordinary temperatures with 1 2 3 4 5 6 OF 7 mols. of water. Indeed the so-called magnesian sulphates give rise to a larger number of variously hydrated compounds of definite character than any other group of salts.It appeared to us of interest especially in view of the investigations of Playfair and Joule and of Schiff t o determine the precise relation of the specific volume of a salt to its degree of hydration ; and in this communication we beg to lay before the Society the results of our observations on such of the variously hydrated sulphates of copper, magnesium zinc nickel cobalt iron and manganese as we could obtain in a definite form. The investigation of this subject was undertaken many years ago by Dr. Playfair in continuation of the series of researches published by him in conjunction with Dr. Joule but although considerable progress was made in the work various circumstances prevented its completion. On learning that one of us was engaged on the question, Dr.Playfair kindly placed the very ample notes of his investigation a t In salts less highly hydrated this law does not hold good TBORPE ASD M'-jTTS ON THE SPECIFIC VOLUME ETC. 103 O u r disposal and although we have a t his suggestion gone over the whole of the ground again much of the experimental matter of the present communication is confirmed by his previous observations. OUY investigation was made partly in the laboratory of the Yorkshire College and partly in that of the Owens College under Professor Enwoe's supervision. We give whenever necessary the mode of preparation of the various hydrates ; the identity of these was in all cases ascertained by analysis usually by tlie estimation of the water.The determination of the specific gravity was effected by weighing in benzene and the finai rcsults are the means of several concordant determinations made by tile aid of different bottles. I n the case of the anhydrous or other liygroscopic salts the bottles were heated to the proper temperatures :ifher the introduction of the salt until its weight became constant. 111 filling t8he bottles tthe salt was placed in a small specimen tube tfhe iieck of which was closed by a perforated caoutchouc stopper through which was inserted the neck of the specific gravity bottle. By shaking tlie tube when in an inverted position the salt was made t o enter the bottle without undue exposure to air. The weight having been deter-mined the salt was covered with benzene the bottle was placed within the receiver of an air-pump and the exhaustion continued until the benzene boiled.The bottle was then filled up with benzene and placed in a water-bath havizg a constant temperature of 15". The level of the benzene was then adjusted to the mark and the bottle and its contents again weighed. The benzene had been crystal!ised, and boiled at about 80" and was thoroughlydried over sodium. Four determinations of its specific gravity at 15" compared with water at, tlie same ti:mpcrature gave-I 0.8856 I1 0.8860 I11 0.8859 IV 0.8357 Mean. . 0.8858 -I. Copper SuQihate. 1. Air hydrous Copper Sulphate CuS04.-Prepared by heating the Iwntahydrate to 280" until i t ceased to lose water. Three determinations of specific gravity gave-I 3.608 I1 .. . . . . . . . . 3.606 r n . . . . . . . . . . 3.60 Other observations on record are-o r Filhol . . . . . . . . . . . . t7.30 Joule and Playfair. . 3*G:31 Ksrsten 3.5 72 Playfair 3.560 2. iMonohydrated Copper Subhate CuSOJ.H,O.-PI.epttred by heating A Theory The specific gravity bottles were heated to 110' after the powdered pentahydrate to l l O o until it ceased to lose weight. determination of the amount of sulphur gave 18.04 per cent. requires 18.06. the introduction of the salt until the weight was constant. The determinations of specific gravity gave-1 . . . . . . . . . . 3-289 r1 . . . . . . . . . . 3.287 111 . . . . . . . . . . 3.289 Mean. . 3.289 PIayfair (communicated) 3.996. 3. Dihydrated Copper Xulphate CuS04.2H,0.-This hydrate which was first obtained by Playfair was prepared by pouring a cold satu-rated solution of copper sulphate into concentrated oil of vitriol with constant stirring and washing the precipitated salt with absolute alcohol until free from acid.A determination of water gave 18.24 per cent. Theoiy 18.45. --Two detci*minations of specific gravity gave-I 2.952 I1 . . . . . . . . . . 2.954 Mean 2.953 Playfair found that a similar prepara'tion had a specific gravity W E 2.891. He also obtained the dihydrate by boiling the finely powdereti pentahydrate with absolute alcohol. A determinatim of water gave 18.26 per cent ; its specific gravit'y was 2.858 (mean of two determi-nations). 4. Trihydratecl Copper Sulphate CuSOb.SH,O.-This salt whicl I appears not to have been made before was obtained by us by pouring a cold saturated solution of copper.snlphate into an equal volume OE sul-phuric acid of sp. gr. 1.7. The precipitate was washed with small quail-tities of absolute alcohol until free from uncombined salphuric acid. Analysis 1.3952 gram gave 0.349 gram water = 25.01 per cent. Calculated 25-34. 0.5913 gram gave 0.6568 gram Bas04 = 15-25 S per cent. Cal-culated 15.U2 Two citterniinations of specific gravity gave-I . . . . . . . . . . 2.Gii3 I1 . . . . . . . . . . 2.ci6,l A salt of the composition CuSO4.3&H,O l~eptl~en,hlldrated copper sulyhatr, was however obtained by placing the finely powdered pentahydrate over concentrated oil of vitriol u n t i l it ceased to lose weight even a f t e r prolonged exposure.An estimation of copper by standard potassium cyanide gas-e 28.60 per cent. Two determinations of specific gravity gave-All attempts to prepare the tetrahydrate were ansuccessful. Theory requires 28-40. I . . . . . . . . . . 964.5 II . . . . . . . . . . 2.645 Mean . . . . 2.645 A second series of observations on another preparation gave-I . . . . . . . . . . 2650 11 . . . . . . . . . . 2.652 n1ca11 . . . . i.(j,51 -A-This salt also appears not to have been obtained beforc. 5. Pe?ituIi~yd~cttsd C’opper X d p l r a t e CuSOi.5H,O. -Prepared hv repeatedly crystallising the commercial salt. 1,6523 gram pi- e 0-593‘3 gram water = 25-96 per cent. Theory 36.13. ‘1 wo detcrrriinations of specific gravity gave--7.-rij.> 1 .. . . . . . . . . - L-c -I1 . . . . . . . . . . - -CL 3lleaii 2.283 L ) . . ) I t --‘Yhe specific gravit1 of a second preparation which was found to give off 3ti.33 per ccnt. of witer was-C > . b l 9 & I . . . . . . . . . . - i( . I1 . . . . . . . . . . 2.288 Nem . . . . 2.086 _-.-0 t:ier observations on record are-Joule and Playfair 2.278 . . . . . . . . 2.2130 Filhol 2.286 Stolba . . . . . . . . . . . . . . . . . . 2.2i0 3 > > Kopp 2.27 Hydrate . . . . . . . . 0 1 2 Kolecular weight. 159.1 177.1 193.1 Specific vol. according to-T. and W. I'layfair . . . . . . . . $4.7 53.7 67.8 { ""'"> 66.1 . . . . . . 44.1 53.8 Joule and Playf'air 43.8 - -Ram t en - - . . . . . . . . 44.5 t'il iiol . . . . . . . . . . 44.9 - -Stolba - -I - Ropp - .. . . . . . . . . - . . . . . . . . . . I I. JIiy 9 )mix i ) ~ S 11 Iphu te. 1. Anhydrous Hagnesiurn Xulyliate MgS04.-PPreparecl by h e a h g The determinations of specific gravity gave -the heptahgdrate to 28a0 until it ceased to iose weight. I . . . . . . . . . . 2*i08 I1 . . . . . . . . . . 2.T10 Mean 2.709 -0 ther ohservers have found-Pilhol . . . . . . . . . . . . . . . . 2.628 Pape . . . . . . . . . . . . . . . . 2.675 Joule and Playfair . . . . 2.706 h~~lti11g the heptahydrate to 130-140" until it ceased to lose weight. 2. Monohydrated Xagizesium Bulplrnte MgSO4.H20.-Obtained by Two determinations of specific gravity gave-I 2.4-42 II . . . . . . . . . . 2.447 &lean . 2.445 -Playfair found that the monohydrate prepared in the same manner, and which lost 13.24 per cent.water (calculated 13.04) had a specific gravity of 2.478. (mean of two observations). Kieserite (MgSO,.H,O), according to Bischof has a specific gravity of 2,517. 3. Uih ydrated 31agwesiurn Sulphate Mg S 04.2H,0 .-Obtained by boiling the finely powdered heptahy,irate with ab3olute alcohol SPEOIFIC VOLUI\IE OF WATER OF CRPSTIILLISATIOS. 1t)'i 2.0175 grams lost 0.4735 gram water = 23.40 per cent. 23-08. Calculat,ed, Two determinations of specific gravity gave-I . . . . . . 2-374 2.372 I1 . . . . . . . . . . Mean . . 2.373 Playfair who also obtained this salt in the manner described above, and likewise br heating the heptahydrate to loo" found its specific gravity to be 2.279. 4.Penfaluydrated Magnesiz~~z~ Xulphate MgS04,5H,0.-This salt was obtained by Playfair by drFing the heptahydrate over strong sulphuric acid in air until it ceased to lose weight. It contained 43.05 per cent. of water. Its specific gravity (mean of two determinations) was 1.869. 5. Hex11 ydi-ated Magnes iwjn Sdphate Mg SO,. 6H,O .-Prepared by wystsllising a solution of the ordiiiary salt at above 40". 2.7717 gram lost 1.309 gram water = 47.2 per cent. Theory, 4 ; :i 7. The determinations of specific gravity gave-I1 Theory requires 42.8. I . . . . 1.734 1.734 Jlc:in. . . . 1.734 . . . . . . . . -Playfair who prepared the salt in the same manner found its specific 6. Hepttshydruted iiagnesiunz S d p h n t e MgS0,.7H20.-Prepared by 1.415 gram lost on heating 0.7255 gram gravity to be 1.751.rccrystallising Epsom salts. water = 51.2 per cent. Calculated 51.2. A determination of specific gravity gave 11676. A second preparation containing 51.23 per cent. of water gave t,lie I . . . . . . . . 1.678 II . . . . 1.678 Mean . . 1.678 following niimbers :--Other observations on record are-Hassenfratz . . . . . . . . . . 1-660 Kopp . . . . . . . . . . . . . . . . 1.674 Joule and PlnyEair . . . . 1.683 Schiff . . . . . . . . . . . . . . 1.685 Buignet . . . . . . . . . . . . . . 1.67 108 THORPE AXD WATTS ON THE Summary of Results qf Obseruations on Hydrated Mugnesiim Xulphate. Hydrate . . . . . . . . . . . . 0 1 2 5 6 7 Bxolecular weight . . . . 1.20 138 156 210 228 2446 Specific volume according to-T.zlllcl w. . . . . . . . . 44.3 56.4 E'ilhol . . . . . . . . . . . . 45.6 -Pape . . . . . . . . . . . . 44.9 -Joule and Playlair. . 44.4 -Playf air . . . . . . . . . . - 55.7 Rischof . . . . . . . . . . - 54.8 Kopp . . . . . . . . . . . . - -Schiff . . . . . . . . . . . . Hnigne t . . . . . . . . . . __ I - -146% { 146.6 - 146.2 130.2 -- -- 146.9 - 146.0 146.9 -Mean 44.8 55.6 67.0 112.4 130.8 146.6 111. Zinc Sdphate. 1. Atahydrtlus .%PIC Xulpliats ZnS04. - Obtained by heating the Ueterminations of specific gravity-lieptahydrate to 280-300" until it ceased to lose water. I . . . . . . . . . . 3ti29. 11 3-62 7 Mean,. 3.628 A second preparation gave the following numbers -I . . . . . . . . . . 3-621 I1 3.617 Mean 3.61'3 Other observations on record are :-Filhol .. . . . . . . . . . . . . . . 3.400 Playfnir . . . . . . . . . . . . . . 3.413 Joule and P1:Ljfaiim. . . . . . 3.681 Pape . . . . . . . . . . . . . . . . 3.435 2. Il.lonohyclrnted Zinc S i d p h t e ZiiS04.€f,0.-Prepaied by hcating tlie heptahydrate to 100-110" until it ceased to lose weight. 1.2433 gram lost 0.1275 gram water = 10.26 per cent. 1.3623 , 0.1395 , = 10.24 ,, Theory = 10.04 per cent Two determinations of specific gravity gave-I . . . . . . . . 3.283 3.278 I1 . . . . . . . . . . Mean . . 3.280 A second preparation afforded the following numbers :-1 . . . . . . 3.287 3.291 I1 . . . . . . . . hlean . . 3.289 A determination of specific gravity made by Playfair on a salt con-taining 10.08 per cent.of water gave 3.259. 3. Diliydrated Zinc XirZphate ZnS04.2H20.-Obtained by pouring a cold saturated solution of zinc sulphnte into strong sulphnric acid, and washing the precipitate with absolute alcohol until free from un-combined acid. 1.371 gram salt gave 0.2495 gram water = 18.1 per cent. Theory = 18.2 ,, Two determinations of specific gravity gave-I . . . . . . 2.958 2.957 11 . . . . . . . . Mean . . 2.958 4. Penta7qdrated Zinc Xukhatc ZnS04.5B,0.-This salt was ob-tained by boiling the finely powdered heptahydrate with alcohol of sp. gr. 0.825 (Playfair) ; 7.174 grains lost 2.549 grains water or Xi.5 per cent. Theory 36.0. Two determinations of specific gravity gave-I I11 . . . . . . . . . . 2.197 I1 . - . . . . .. 2.205 2.217 . . . . . . . . . . Mean . . 2.206 5. Bexhydrated Zinc Su@hatr? ZnS0,.6H20. - Obtained by crys-Determinations of specific gravit.y-tallising a solution of zinc sulphate at about 40". I . . . . . . . . 2.071 2.075 I1 . . . . . . . . . . Mean . . 2.07 1 10 THORPE AXD WATTS ON THE Playfair also obtained this salt by crystallising a solution a t about 10.35 grains gave 4.175 grains water or 40.30 per cent. Theory Its specific gravity was found to be 2.056. 6. Beptahydrnted Zinc Sidphate ZnSOp.7Hz0. - Ordinary white vitriol after repeated crystallisation contained the following amounts of water :-30". requires 40.29. 1.6963 gram gave 0.7441 gram water or 43.87 per cent. 1.5160 ) 0.6648 ) 7 43.85 7 7 Theory 43-87' per cent. Its sp citic gravity was found to be-I .. . . . . . . . . 1.963 I1 . . . . . . . . . . 1.963 A second sample gave the following numbers :-I . . . . . . . . . . 1.ncx TI . . . . . . . . . . 1.965 Other observations on record are :-Joule and Playfair. . Schiff . . . . . . . . . . . . 1.953 Stolba . . . . . . . . . . . . 1.9534 Holker 1.976 1,931 (mean of 4 observations). Buignet . . . . . . . . . . 1.95 7 Sunarnary of Results of Observations o n Hgdrated Zinc Sulphates. Hydrate . . . . . . . . . . 0 1 2 5 6 7 Molecularweight . . 161 179 197 251 269 287 Specific volume according to-- - Filhol . . . . . . . . . . 47.2 -Playfair . . . . . . . . 47.1 55-33 - 113.7 Jonle and Playfair. 43.7 - - -Pape . . . . . . . . . . . . 46.8 -Buignet . . . . . . . . .. - -- - - - Schiff . . . . . . . . . . . . S to1 ba . . . . . . . . . . Holker . . . . . . . . . . - - - -- - - -- - - -130.8 148.G - 148.5 - 146.9 - 146.6 - 146-9 - 145.3 - -Mean . . . . 45.6 54.7 66.6 113.7 130.2 146. SPECIFIC VOLUME OF WATER OF CRfYThLLISAITION. 11 I ITr. K i c k e l Xltlp7rde. 1. Adlyclmus Nicliel Sdphnte NiSO1. - Prepared by heating 3 weighed quantity of the heptahydrated salt a t 250° until it ceased to lose weight. Calculated loss = 1.33 gmms. 2.964 grams lost 1.330 grams H,O. Two determinations of specific gravity gave :-I . . . . . . . . . . 3.419 I1 . . . . . . . . . . 3.417 Mean . . 3.418 -. -Playfair obtained 3,526. 2. Ahnohydrated Nickel Sdpliate NiSO4.H20.-Prepared by heating 0.3585 gram lost 0.03CiO gram H20 = 10.03 per cent.Theory, 3. Hezhydrated Nickel Sdphate NiS0,.6H20.-Prepared by crys-0.4682 gram lost on heating 0.191 gram = 40.8 per cent. Theory, A determination of specific gravity gave 2.031. TopsoB obtained values varying from 2.042 to 2.074. 4. Heptahydrated Nickel Sulphafe NiSOd.7H20. - So-called pure nickel snlphate of commerce was freed from cobalt by treatment with chlorine adding barium carbonate in excess filtering precipitating the nickel in the filtrate with potash and after well washing dis-solving the oxide in sulphuric acid and recrystsllising. Theory, 44.9. the heptahydrate at loo" until its weight was constant. 10.40. tallising a solution of nickel sulphate at a temperature above 40". 41.2. 2.964 gram lost 1.33 gram on heating = 44.9 per cent.Two determinations of specific gravity gave :-I . . . . . . . . . . 1.949 I1 . . . . . . . . . . 1.948 Mean 1.949 -A determination on a second preparation gave 1.945. Schiff observed 1.931 112 THORPE AND WATTS ON THE S u n m a y of Results of Observations on Hydrated Nickel Sulplzate. Hydrate 0 1 6 7 Molecular weight 154.7 172.7 262.7 280.7 Specific volume according to-T. and W. 4rj.2 56.6 - { :::: Playfair . . . . . . . . . . 43.9 56.4 129.3 -- 128.6 - TopsoS -- 145.4 Schiff - -Mean 44.6 56.5 129.0 144.6 V. Cobalt Sulpkate. 1. Anhydrous Cobalt Sulphate CoS04. -Obtained by drying the Eieptahydrate at 250". A determination of specific gravity gave 3.472. Playfair obtained 3.444. 2. Monohydrated Cobalt Sulphate CaS04.H,0.-Prepared by heating the heptahydrate a t 100" until it ceased to lose weight.Its specific gravity was found to be 3.125. 3. Bihydmted Cobalt Sulpha,te CoS04.2H,0.-Prepared by boiling the finely powdered heptahydrate with absolute alcohol. 0.229 gram lost 0-0435 gram water = 18.9 per cent.; calculated 18.9. Playfair also obtained the salt in the same manner and found the specific gravity to be 2.712. 4. Tetrahydrated Cobalt Xulpphnte CoSO4.4H2O.-Obtained by ex-posing the finely powdered heptahydrate over oil of vitriol until its weight was constant. 5. Pendahydrated Cobalt S.dphate CoS04.5H20.-This hydrate was obtained by Playfair by drying the heptahydrated salt over sulphuric acid. 3.475 grams gave 1.290 gram water = 37.1 per cent. Calculated, 36.7.6. Hex hydrated Cobalt Suly hnte Co S 04. 6 H,O .-Prepared by cr ys-tallising a solution of cobalt sulphate a t about 25"-0.5400 gram lost 0.2190 gram H20 = 40.6. Theory 41.2 The specific gravity was found to be 2.019. 7. Reptahydraied Cobalt Sulyhate CoSOd.7H20.-Prepared by re-crystallising pure cobalt sulphate. The salt was freed from nickcl by treatment with chlorine and barium carbonate solution in acid repre-cipitation with potash and re-solution in sulphuric acid. Schiff observed 1.924. The specific gravity was 2.668. Sp. gr. 2.327. A determination of specific gravity gave 2.134. A determination of specific gravity gave 1.918 SPECIFIC VOLUME OF WATER OF CRYSTALLISATION. 1 13 Summary of Eesdts of Observations o n Cob& Szclphate.Molecular weight. 154.7 172.7 190.7 226.7 244.7 262.7 280.7 Hydrate 0 1 2 4 5 6 7 Specific volume according to-T. and W. . . . . . . 44.5 5.5.2 71.5 97.4 - 130-1 146.4 - - - - 145.5 Schiff Playfair . . . . . . . . 44.9 - 70.3 - 114.6 - -- I ~ Mean 44.7 55.2 70.9 97.4 114.6 130.1 146.0 VI. Nangnnous Sidplmte. 1. Anhydrous Mangmous Sz@hate MnS04.-Obtained by heating the pentahydrate to 280" until it ceased to lose weight. Its specific gravity was found to be 3.282. Playfair observed 3.386. 2 . ,VorLohycl.r.ated Maiiganous Xulplza3te blnS04.H20.-Prepared by drying the pentahydrate at 100" until no further loss of weight mas observed. Theory 10.74. A determination of specific gravity gave 2,845. Playfair ob-served 3.210. 3. D ihyldrated Man g itn ozcs S d p ha t e S 04.2H20 .-0 btained b JT boiling t'he finely powdered pentahydrate with absolute alcohol. This hydra+e may also be prepared by pouring a satuyatecl solution of the pentaliydrate into oil of vitriol. Theory 19.35. 1.1.315 gram lost 0.1250 gram HzO = 11.04 per cent. 1.183 gram lost 0.2275 gram water = 19.20 per cent. Two determinations of specific gravity gave :-I 2.526 IT 2-525 Mean 2.526 4. T d u ~ dr ated JIan gal ious Szc lp h ate Mn S 0,. 3H,O. -0 bt ained by Playfair by evaporating a solution of the sulphate a t a boiling heat until a pellicle formed on the Surface removing this and drying it rapidly between hot filter-paper. 5.875 grains gave 1.535 grains H,O = 26.1 per cent. Theory 26.2. Sp. gr. '2.356. 5. Tet rak y clyated AIa tapzotLs Sui$ h i t te Jf nS 04.4H20.-This hydrate, according to TopsoG has a specific gravity of 2.261, 6. Pentahy drat ed Mmgm OZLS S idp A CI te Mn SO4 :5H20. - 0 b tained by repeatedly crystallising the ordinary sulphate. Two concordant deter-VOL. XXXVIT. 114 TEIORPE AXD KATTS OK THE minations of specific gravit,y gave 2.103. 2.087. Kopp obtained 2.095 and 8um.mary of Results of Ohservat ions on Manylxnous Xulpliates. Hydrate 0 1 2 3 4 5 Molecular weight 150 168 186 204 222 240 Specific volume according to-T. and W. 45.7 59.1 73.6 - - 114.1 Playfair 44.3 52.3 - 86.6 -Tops05 --95.2 - - -- - - - Kopp Mean 45.0 55.7 73.6 86.6 98.2 114.4 VII . F e w o us Xu lp hate. 1. Anlydrous Ferrous Sulp!iate FeS04.-Obtained by heating the powdered heptahydrate in a current of hydrogen.Analysis showed that i t was anhydrous. Its specific gravity was 3.346. Playfair observed 5-48. 2. A l ~ n o h ~ ~ d r a t e d Ferrous Xup7zate FeSOl.H,O.-Prepared b y heating the powdered heptahydrate in a current of hydrogen a t 120". An estimation of iron by potassium permanganate solution gave 32.6 per cent. Theory 32.9. Sp. gr. 2.994. Playfail. found 3.047. 3. Di7iydmted Ferrous Sulpyhafe FeS04.2H,0.-Obt8ained by boiling the heptahydrate with successive quantities of absolute alcohol. Sp. gr. 2.773. 4. T e t rahydi-ated Ferrous Sulyli ate Fe S 04.4H,0 .-OW ained by ex-posing the finely powdered heptahydrate over oil of vibriol in an atmosphere of carbon dioxide until it ceased to lose weight. An estimation of iron by standard potassium permanganate solut,ion gave 25.3 per cent.Calculated 25.0. Sp. gr. 2.227. 5 . Heptahydrated Perrous Sulphate FeSOp.7H20.-It has been thought unnecessary to add to the determinations of the specific gravitS of this salt already on record. Joule and Playfair 1.889 Buignet 1.902 Filhol 1.904 Schiff 1.88 SPECIFIC VOLUME OF JTATER OF CRYSTALLISATION. 11 5 130.8 130'2 199.0 130.1 - --Xumnzary of Results of 0bsermtion.c 011 Fewous Xulphntes. Molecularweight. 152 170 183 224 2 i 8 Hydrate 0 1 2 4 7 - -146.6 146.8 144% 146.0 146 -7 Specific volume according to-44.4 44.8 45.6 44.6 44.7 45.0 44.5 44-8 T. and W. 45.4 56.7 67.7 100.5 -Playfair 43.6 55.7 -Joule and Playfair - - -Buignet I - -- -- 147.2 - 146.0 - 147.5 - 146-1 - I - Filhol Schiff - - -54.3 55.6 54 7 56.5 55'2 55.7 56.2 55-5 -___ Mean,.. 44.5 56.2 67.7 100.5 146.7 On comparing the foregoing observations ,it is evident that the anhydrous sulphates of copper magnesium zinc nickel cobalt man-ganese and iron have identical specific volumes ; or since we may define specific volume as the volume in cubic centimetres occupied by the equivalent of the salt in grams it follows that equivalent quantities of these different sulphates occupy the same bulk in space. A like con-clusion as regards certain of these anhydrous sulphates has already been drawn by Playfair and Joule. A further consideration of the numbers warrants us we believe in supposing that this conclusion may be extended to the various hy-drates of these salts.The evidence on which this assumption is grounded is contained in the following table which is merely a synopsis of the experimental results detailed in the foregoing pages :-Hydrate, Copper sulphate Magnesium sulphate . Zinc sulphate Nickel sulphate . Cobalt sulphate . Manganous sulphate . Ferrous sulphate Mean of means I -2 67 '0 67 '0 66.6 70 .Y 73 -6 67.7 --5 109 -1 112 '4 113.7 114 *G 114.4 ---112 -9 -Some of these numbers are not so precise as we could wish it would have been more satisfactory for example to have obtained a larger number of observations on the trilsydratcs. But these interme-diate hydrates are obtained with great difficulty owing in great part to the indefinite character of the methods of preparation ; indecd b 116 THORPE AND WATTS OK T6E far the greater portion of the time occupied in what has proved to bc a very tedious research was spent in attempts in many cases fntile, to procure them in a state of purity.An examination of our experi-mental data will make it clear that the disparities between t)he values obtained for the different members of each series are almost entirely due to accidental variations in the degree of hydration of the salts, and not to errors in the determinations of the specific gravities ; errors of this kind such as are likely to occur would exercise only a com-paratively small influence on the result. That the disparities are actually accidental would seem to be proved by the factl that no r e p -layity or symptom of order can be discovered in the mode of the variation.We think therefore we are justified in concluding that what Playfair and Joule have shown to be true of certain of the anhjdrons sulphates of the form M"SO4 and what Schiff has shown to hold good in the case of the hydrated sulphates of the form ;RJI"SO,. '?H,O-and their results are confirmed by our own independent observations-is equally applicable to the case of the intermediate hydrates. The final mean then of each series will afford us an ap-proximation to the true specific volume of the particular hydrate arid enable us therefore to trace the influence of the varying degree of hydrat'ion on the bulk of the salt.The first and main conclusion we draw from our observations is that in the case of the so-called magnesian sulphntes the volume occupied by the several molecules of water varies with the degree of hydration. The first molecule of water the constitutional water or " water of halhydration '' of Graham occupies considerably less bulk than the remaining molecules ; its mean relative value is 10.7. Each additional molecule appears to occupy a gradually increasing volume. The difference between the monohydrate and dihydrate is 13.3 ; be-tween the dihydrate and trihydrate it is 14.5 ; between the trihydrate and tetrahydrate it is 15.4. There is a break in the continuity of the rate between the tetrahydrate and pentahydrate due to the low value found for copper sulphate.The difference between the hexhydrate and heptahydrate is 16.2. We give these numbers merely as first approximations since a far larger number of observations made upon hydrates of definite composition will be required to fix the exact values. We would point out however that our main conclusion is in harmony with experience. The general fact that the different molecules of water in a hydrat,ed salt' are held with varying degrees of tenacity as shown by the difference in the intensity of heat needed to expel them, is of course well known. Now as has already been pointed out by Muller chemical combination is generally attended by contraction and the stability of the resulting compound corresponds with if it is not dependent on the diminution of bulk. It would be a problem of con SPECIFIC VOLUME OF WATER OF CRTSTALLISXTION.11 'i siderable interest in the light of these results to determine tlre different quantities of heat evolved in the combination of successivc molecules of water with these anhydrous sulphates. Graham nearly forty years since made the beginning of such a research. From com-parative experiments made with the anhydrous sulphates of manganese, copper zinc and magnesium and the monohydrates of these salts, Graham found that far more heat was developed in the act of com-bination of the first molecule-that in which the greatest contraction occurs-than is evolved in the combination of any of the remaining molecules; the amount in the case of the first molecule mas from a fourth to a third of that needed for the complete hydration of the salt, These observations have been greatlp extended by Favre and Valson (Compt.rend. 73,1144; 74 2016 1065 ; 75 798 925 1000 1066, 1071) who have determined the amount of heat produced or abstracted by the solution of sulphates of various degrees of hydration in water. The observations were made on a number of the sulphates mentioned in the foregoing pages on certain double sulphates and on the alums. The results so far as they are applicable to the salts under considera-tion are as follows :*-cuso CuSO,.HO CuS045HO MgSOa MgSO4.HO MgS 0,7H 0 . . . . . . . . . . . . . . . . ZnSO ZnS04.H0 . . . . . . . . . . . . . . . . ZnS047H0 NiS047H0 CoS047HO lSiInSOa MnS04H0. . Mn S 0 ,5 H 0 FeS047H0 Heat-units. 8149 4734 - 1216 10152 5493 - 1860 9289 481 2 - 20'74 - 1944 - 1680 7085 4216 235 - 2182 These numbers which express the amount of hcat evolved by the solution of 1 equiv. of the salt in grams in 1 litre of water are not exactly comparable with those of Graham but they serve to confirm the general conclusion that the heat due to the combination of the first molecule of water is much greater than that evolved in the com-bination of the succeeding molecules. * 0 = 8 S = 16

ISSN:0368-1645    

DOI:10.1039/CT8803700102

出版商:RSC    

年代:1880

数据来源: RSC