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J 0 U R N A L OF THE CHEMICAL SOCIETY, TRANSACTIONS. A. J. ALLMAND M.C. D.Sc. A. W. CROSSLEY C.M.G. C.H.E., SIR JAMES J. DOBBIE M.A. D.Sc., M. 0. FORSTER D.Sc. Ph.D. F.R.S. T. A. HENRY D.Sc. J. T. HEWITr M.A. D.Sc. Ph.D., D.Sc. P.R.S. F.R..S. F.R. 8. C. A. KEANE D.Sc. Ph.D. H. R. LE SUEUR D.Sc. T. M. LOWRY C.B.E.,D.Sc. F.R.S. J. I. 0. MASSON M.B.E. D.Sc. G. T. MORGAN O.B.E. D.Sc., J. C. PHILIP O.B.E. DSc. Ph.D. A. SCOTT M.A. D.Sc. F.R.S. F.R.S. 6Ebifur : J. C. GAIN D.Sc. Sub- @Ebifar : A. J. GREENAWAY. &eistarrt Sab.-@;bEfol : CLARENCE SMITH D.Sc. 1920. Vol. CXVII. LON DON : GURNEY & JACKSON 33 PATERNOSTER ROW E.C. 4. 1920 PRINTED IN GREAT BRITAIN BY RICHARD CLAY & SONS LIMITED, PARIS GARDEN STAMFORD ST. 5. E . 1, AND BUNGAY SUYBOLK J O U R N A L OF THE CHEMICAL SOCIETY.TRANSACTIONS. A. J. ALLMAND M.C. D.Sc. A. W. CROSSLEY C.M.G. C.B.E., SIR JAMES J. DOBBIE M.A. D.Sc., M. 0. FORSTER D.Sc. Ph.D. F.R.S. T. A. HENRY D.Sc. J. T. HEWITT M.A. D.Sc. Ph.D., D.Sc. F.R.S. F. R. S. F.R. S. C. A. KRANE D.Sc. Ph.D. H. R. LE SUEUR D.Sc. 1’. M. LOWRY C.B.E. D.Sc. F.R.S. J. I. 0. MASSON M.B.E. D.Sc. G. T. MORGAN O.B.E. D.Sc., J. C. PHILIP O.B.E. D.Sc. Ph.D. A. SCOTT M.A. D.Sc. F.R.S. F.R.S. dbiior : J. C. CAIN D.Sc. Snb- mdar : A. J. GREENAWAY. %misfant Snb- @;bitor : CLAREWE SMITE D. Sc. 1920. VoL CXVII. Part I. pp. 1-818. LONDON: GURNEY & JACKSON 33 PATERNOSTER ROW E.C. 4. 1920 PRINTED IN GREAT B R f i A I X BY RICH.4RD CLAY &5 SONS LIMITED, PARIS QARDEN STAXFORD ST.S.E. 1, AND BUNGAY SUElWLK CONTENTS. PAPERS COMMXJNICATED TO THE CHEMICAL SOCIETY, 1.-A Nqw Modification of 3 4-Dinitrodimethylaniline. By HER-BERT SWANN . 11.-The Chloroacetates of S-Alkylthiocarbamides. By JOHN TAYLOR . 111.- The Electroaffinity of Aluminium. Part I. The Ionisa-tion and Hydrolysis of Aluminium Chloride. By JAROSLAV HEYROVSKP . 1V.-The Electroaffinity of Aluminium. Part 11. The Alumin-ium Electrode. By JAROSLAV HEYROVSKY . . V.-The Propagation of Flame in Mixtures of Methane and Air. Part I. Horizontal Propagation. By WALTER MASON and RICHARD VERNON WHEELER V1.-The Propagation of Flame in Complex Gaseous Mixtures. Part I'V. The Uniform Movement of Flame in Mixtures of Methane Osygen and Nitrogen.'' Maximum-speed Mixtures " of Methane and Hydrogen in Air. By WILLIAM PAYMAN . VI1.-The Solubility of Sulphur Dioxide in Sulphuric Acid. By FRANK DOUGLAS MILES and JOSEPH FENTON VII1.-Phloroacetophenone. By KIEMUD BEHARI SEN and PRAPHULLA CHANDRA GHOSH . 1X.-The Peroxides of Bismuth. By RICHARD ROBERT LE GEYT WORSLEY and PHILIP WILFRED ROBERTSON . X.-The Action of Mercuric Cyanide on Metallic Salts. By LILANANDA GUPTA . XI.-Acyl Substituted isol'hiohydantoins. By AUGUSTUS ED-WARD DIXON and RAYMOND THOMAS JOACHIM KENNEDY . XI1.-Carboalkyloxythiocarbamides. By AUGUSTUS EDWARD DIXON and RAYMOND THOMAS JOACHIM KENNEDY XII1.-Organic Derivatives of Tellurium. Part I. Dimethyl-telluronium Dihaloids. By RICHARD HENRY VERNON . X1V.-The Action of Aqua Regia on Gold-Silver Alloys in the Presence of Ammonium Salts.By WILLIAM BRANCH POLLARD . . . . . . PAGP, 1 4 11 a7 36 48 59 61 6 3 67 74 80 86 99 XV.-Intramolecular Rearrangementi of the A1 kylarylamines : Formation of 4-Amino-n-butylbenzene. By JOSEPH REILLY and WILFRED JOHN HICKINBOTTOM . . 103 XV1.-The Condensation of Ethyl Acetoacetate with p-Di-methylaminobenzaldehyde and Ammonia. By LEONARD ERIC HINKEL and HERBERT WILLIAM CREMER . . . 13 iv CONTENTS. PAGE XVI1.-Constituents of the Leaves of Helinzcs ovatus. By JOHN AuausTus GOODSON . . 140 XVII1.-Contributions to the Chemistry of the Terpenes. Part XIX. Synthesis of a m-Menthadiene from m-iso-Cymene By GEOEGE GERALD HENDERSON and THOMAS FREDERICK SMEATON .. . 144 X1X.-The Effect of a Change in Temperature on the Colour Changes of Methyl-orange and on the Accuracy of Titra-tions. By HENRY THOMAS TIZARD and JOHN REGINALD HARVEY WHISTON . . . 150 XX.-The Rate of Decomposition of Malonic Acid. By CYRIL NORMAN HINSHELWOOD . 156 XXL-Some Observations on the Action of Coal upon a Photo-graphic Plate. By ERIC SINKINSON . . . 165 XXK-The Sorption of Hydrogen by Palladium at Low Tem-peratures. By JAMES BRIERLEY FIRTH . . 171 XXII1.-The Interaction of Chlorine and Marsh Gas under the Influence of Light. The Conversion of Methyl Chloride to Methyl Alcohol and Methyl Acetate. By JOHN REGINALD HARVEY WHISTON . . 183 XX1V.-Studies in the Resolution of Racemic Acids by Optic-ally Active Alcohols. Part I. The Resolution of r-Tartaric Acid by LBorneol.By HENRY WREN HOWELL WILLIAMS and WILLIAM WHALLEY MIDDLETON . XXV.-The Constitution of the Disaccharides. Part IV. The Structure of the Fructose Residue in Sucrose. By WALTER NORMAN HAWORTH . XXV1.-Phthaleins and Fluorans. By MAURICE COPISAROW . XXVI1.-Certain Binary and Ternary Mixtures of Liquids having Constant Boiling Points. By WILLIAM RINGROSE GELSTON ATKINS . XXVII1.-The Estimation of Nitrogen in Nitrocellulose and Inorganic Nitrates with the Nitrometer. By ERNEST GEORGE BECKETT . SX1X.-The Preparation of Methylamine from Ammonium Methyl Sulphate. By WILLIAM SMITH DENHAM and LIONEL FREDERICK KNAPP . XXX.-The Behaviour of the Constituents of Banded Bitumin-ous Coal on Coking. Studies in the Composition of Coal.XXX1.-Tha Mineral Constituents of Banded Bituminous Coal on Coking. Studies in the Composition of Coal. BY RUDOLF LESSING . XXXI1.-Z-Hexylsuccinic Acid. By HENRY WREN and HENRY BURNS . By RUDOLF LESSING . 191 199 209 218 220 236 247 256 26 CONTENTS. V PAGE XXXII1.-Surface Tension of Mixtures of Water and Alcohol. By JAMES BRIERLEY FIRTH . XXXIV.-PP'-Dichloroethyl Sulphide. By CHARLES STANLEY GIBSON and SIR WILLIAM JACKSON POPE . ' . XXXV.-The Action of Ethyl Chloroformnte on Pyridine and Quinoline. By THONAS HOPKINS . XXXVL-The Action of Nitric Acid on Unsnturatecl Hydro-carbons. The Action of Nitric Acid on Acetylene. By KENNEDY JOSEPH PREVITP ORTON and PHYLLIS VIOLET MCHIE , XXXVI1.-Synthetical Experiments with PP'-Dichloroethyl Sulphide.By WILLIAM DAVIES . XXXVlI1.-Some Derivatives of Fisetol. By W ILLTAAI KER-SHAW SLATER and HENRY STEPHEN . XXX1X.-The Effect of Heating on the Absorptive Power of Sugar-charcoal for Sulphur Dioxide. By R.AMSAT MIDDLE-TON WIXTER and HERBERT BRERETON BAKER . XL.-Compounds of Thiocyanates of certain Bivalent Metals and Hydrazine. By PRIYADARANJAN RAY and PULIN VIHARI SARKAR . XL1.-Some Condensations of n-Butyl Alcohol and n-Butalde-hyde. By CHARLES WEIZMANK and STANLEY FREDERICK GARRARD . XLI1.-An Investigation of the Resin from Species of Xmthor-rhea not previously examined. By EDWARD HENRY RENNIE, WILLIAM TERNENT COOKE and HEDLEY HERBERT FINLAYSON. XLII1.-Coagulation of Metal Sulphide Hydrosols. Part 11. Influence of Temperature on the Rate of Coagulation of Arsenious Sulphide Hydrosols.By J~~ANENDRA NATH MUKHERJEE . XL1V.-The Preparation of Halogenohydrins. By JOHN READ and MARGARET MARY WILLIAMS. XLV.-The Activation of Wood-charcoal by Heat Treatment. By JAMES C. PHILIP SYDNEY DUNNILL and OLIVE WORKMAN XLV1.-The Composition of Sslvarsan. By ROBERT GEORGE FARGHER and PRANK LEE PYMAN . XLVI1.-The Solubility of Potassium Bromide in Bromine Water. By ALFRED FRANCIS JOSEPH . War Experiences in the Xanufacture of Nitric Acid and the Recovery of Nitrous Fumes. A Lecture Delivered before the Chemical Society on December 18th 1919. By JANES WALKER . XLVII1.-The Influence of Position on the Boiling Points of Isomeric Benzene Derivatives. By KEVIL VINCENT SIDGWICK . 268 27 1 27 8 283 297 309 319 32 1 324 338 350 359 362 370 377 382 38 vi CONTENTS.XLIX.-Tolatility in Steam Benzoic Acid and its Derivatives. By NEVIL VINCENT SIDGwIck . . L.-Observations on Some Organic Compounds of Arsenic. By ALEX. MCKENZIE and JOHN KERFOOT WOOD . . ANNUAL GENERAL MEETIKG . PRESIDENTIAL ADDRESS . OBITUARY NOTICES . LI. -The Falling Sphere Viscosimeter. By WILLIAM HOWIESON GIBSON and LAURA MARY JACOBS . LI1.-The Viscosity of Solutions of Cellulose. Part I. By WILLIAM HOWIESON GIBSON. Part 11. By WILLIAM HOWIESON GIBSON [with LEO SeENcER and ROBERT McCALL] L1II.-The Influence of the Solvent on the Velocity of Reaction between certain Alkyl Iodides and Sodium /3-Naphthoxide. By HENRY EDWARD Cox . . L1V.-The Introduction of the Chloromethyl Group into the Aromatic Nucleus.By HENRY STEPHEN WALLACE FRANK SHORT and GEOFFREY GLADDING . LV.-A New Hydrogen Sulphide Generator. By BERTRAM DILLON STEELE and HENRY GEORGE DENHAM . LV1.-Direct Experimental Determination of the Concentration of Potassium and Sodium Ions in Soap Solutions and Gels. By CYRIL SEBASTIAN SALMON . LVI1.-Studies in Ernulsions. Part I. A New Method of Determining the Inversion of Phases. By SHAXTI SWARUPA BHATNAGAR . LV1II.-The Decomposition of Nitric Esters by Lime. By THOMAS MARTIN LOWRY KENDALL COLIN BROWNING and JOSHUA WILLIAM FARMERY . LIX.-Note on the Constituents of Morilzda citrifolia. By JOHN LIONEL SIMONSEN . LX.-Syntheses with the Aid of Monochloromethyl Ether. Part IV. The Condensation of Ethyl Benzyl Sodiomalonate and Monochloromethyl Ether.By JOHN LIONEL SIMONSEN . LX1.-The Constituents of Indian Turpentine from .Pinus Zongifolia Roxb. Part I. By JOHN LIONEL SIMONSEN . LXI1.-The Cyanine Dyes. Part I. The Constitution of the isocyanines. By WIILTAM HOBSON MILLS and ROBERT SCOTT WISHART . LXII1.-Experiments on the Preparation of Oximino-deriv-atives. By WILLIAM KERSHAW SLATER . LX1V.-The Formation and Stability of Associated Alicyclic Systems. Part I. A System of Nomenclature and some Derivatives of Methane-11-cyclopropane and of Methsne-111-cyclopropane. By XICHARD MOORE BEESLEY and JOCELYN FIELD THORPE [with Note by C. K. INGOLD] , PAGE 396 406 41 6 430 444 473 479 493 510 527 530 542 552 561 564 570 5 79 587 59 CONTENTS.vii PAGE LXV.-Colouring Matters of Red and Blue Fluorite. By CECIL STEVENSON GARNETT . * . LXY1.-Studies in Catalysis. Part XIII. Contact Potentials and Dielectric Capacities of Metals in Relation to the Occlusion of Hydrogen and Hydrogenation. By WILLIAM CUDMORE MCCULLAGH LEWIS . LXVI1.-The Preparation of cycZoHeptane-1 1 -diacetic Acid. By JAMES NELSON EDMUND DAY GEORGE ARMAND ROBERT KOX and ARNOLD STEVENSON . . LXVII1.-Estimation of Nitroform by Potassium Permanganate. By PHYLLIS VIOLET MCKIE . LX1X.-The Action of Alcohol on the Sulphates of Sodium. By GERALD SNOWDEN BUTLER and HORACE BARRATT DUNNICLIFF . LXX.-Orientation of the Nitro- and Arylazo - glyoxalines. Fission of the Glyoxalone Nucleus. By ROBERT GEORGE FARGHER .LXX1.-The Behaviour of Optically Active Esters on Hydrolysis. By ALES. McKENztE and HENRY WRW LXXI1.-The Use of ap-Dichlorovinyl Ethyl Ether for the Production of Chloroacetates and Acid Chlorides. By HOLLAND CROMPTON and PAULE LAURE VANDERSTICHELE . LXXII1.-Electrolysis of Hydrogen Bromide in Liquid Sulphur Dioxide. By LANCELOT SALISBURY BAGSTER and GEORQE COOLING . LXX1V.-Some Properties of Benzanthrone. By ARTHUR GEORGE PERKIN . LXXV.-n-Butyl Chloroformate and its Derivatives. By FREDERICK DANIEL CHATTAWAY and EDOUARD SAERENS . LXXV1.-Isomeric Phthalpl hydrazides. By FREDERICK DANIEL CHATTAWAY and WILLIAM TESH . LXXVI1.-The Acylation of Thiocarbamides. Ey AUGUSTUS EDWARD DIXON and JOHN TAYLOR . LXXVII1.-A New Series of Nitrogenous Compounds obtained from Camphoroxalic Acid.By PERCY CHORLEY and ARTHUR LAPWORTH . . . LXX1X.-Homocamphor. By ARTIIUR LAPWORTH and FRANK ALBERT ROYLE . . . LXXX.-The Nitration of Acetom-toluidide. By JAMES WILFRED COOK and OSCAR LISLE BRADY . LXXX1.-Studies in the Camphane Series. Part XXXVIII. The Cyanohydrazone of Camphorquinone. By MARTIN OXSLOW FORSTER and WILLIAX BRISTOW SAVILLE . LXXXI1.-Organo-derivatives of Bismuth. Part 111. The Preparation of Derivatives of Quinquevalent Bismuth. By FREDERICK CHALLENGER and ARCHIBALD EDWIN GODDARD . . . 620 623 639 646 649 668 680 69 1 693 696 708 711 720 728 743 750 75 3 76 ... V l l l CONTEKTS. LXXXI1.T.-Note on the Preparation of certain Iodo-compounds. By CUTHBERT WILLIAM JAMES JAMES KENNER and WILFRID VICTOR STUBBINOS .LXXXIV.-Diphenylarsenious Chloride and Cyanide. (Di-phenylchloroarsine and Diphenylcyanoarsine.) By GILBERT T. MORGAN and DUDLEY CLOETE VINING . . . LXXXV.-ortho-Chlorodinitrotoluenes. Part I. By GILEERT T. MORGAN and HARRY DUGALD KEITH DREW LXXXVT.-The Oxidation of the Ingredients of Banded Bituminous Coal. Studies in the Composition of Coal. By FREDERICK VINCEKT TXDESWELL and RICHARD VERNON WHEELER . LXXXVII.-8 - Hydroxy - 2 3 - quinoxanthone. By HARRY FITZGIBBON DEAN and MAXIIIILIAN NIEREN STEIN . LXXXVIIL-The Decomposition of Nitric Esters. By ROBERT CROSBIE FARMER . LXXX1X.-The Viscosity of Solutions of Nitrocellulose in Mixtures of Acetone and Water. By IRVINE MASSON and ROBERT MCCALL . . G .XC.-The Electrical Conductivity of Pure Salts in the Solid and Fused States. Determination of the Activity-coefficients of Ions in Solid Salts. By JNANENDI~A CHANDRA GHOSH . X CI .-The Constitution of Yellow Sulphide Dyes. By JATINVRA KUMAR MAZUMDER and EDWIN ROY WATSON . . XCI1.-The Determination of the Relative Strengths of some Nitrogen Bases of the Aromatic Series and of some Alkaloids. By FRANCIS ARNALL. . XCII1.-The Transition from Coal to Coke. By ERIC SINKINSON . XC1V.-Periodic Precipitation. Part I. Silver Chromate in Gelatin. By ALEXANDER MITCHELL WILLIAMS and MARY RUSSELL MACKICNZIE . . . XCV.-The Influence of Nitro-groups on the Reactivity of Substituents in the Benzene Nucleus. Part 11. The Dinitrotoluenes. By JAMES KENNER and MICHAEL PARKIN .XCV1.-Complex Metallic Ammines. Part 111. Dichloro-tetrapyridinecobalt Salts. By THOMAS SLATER PRICE . . XCVI1.-Arsinic Acids Derived from Guaiacol and Veratrole. Constitution of the Polyarsenides. By ROBERT GEORGE FARGHER . . . XCVIII.-2 3 6-Trinitrotoluene a new Synthesis. By OSCAR LISLE BRADY and ARTHUR TAYLOR XCIX,-The ERect of Reducing Agents on Tetranitromethane, and a Rapid Method of Estimation. By AILEEN BAILLIE, ALEXANDER KILLEN MACBETE and NORAH IRENE MAXWELL. . . 773 777 784 79 4 802 806 819 823 830 835 839 844 85 2 860 865 876 88 CONTENTS. ix PAGE ANNUAL REPORT OF THE INTERNATIONAL COMMITTEE ON ATOMIC WEIGHTS FOR 1920-1921 . . 885 C.-Organic Derivatives of Tellurium. Part 11. Constitution of the Dimethyltelluronium Dihnloids.By RICHARD HENRY VERNON . . 889 C1.-Volumetric Estimation of PP'-Dichloroethyl Sulphide. By WILLIAM FRANCIS HOLLELY. . . 898 CI1.-The Ignition of Gases. Part I. Ignition by the Impul-sive Electrical Discharge. Mixtures of Methane and Air. CII1.-The Composition of Ancient Eastern Bronzes. By MASUMI CEIBASHIGE . . 917 Helium its Production and Uses. A Lecture Delivered before the Chemical Society on June 17th 1920. By JOHN CUNNINGHAM MCLENNAN . . 923 . C1V.-Some New Derivatives of Mesitylene and q-Cumene. By CHARLES STANLEY GIBSON . . 948 CV.-Studies on Hypophosphorous Acid. Part I. Its Ionisa-CVL-Derivatives of Gallic Acid. Part I. Synthesis of 4-Hy droxy-3 5-dimethoxyphthalic Acid. By RUPCHAND LILARAM ALIMCHANDANI and ANDREW NORMAN MELDRUM .964 CVI1.-The Constitution of Catechin. Part I. By MAXIMILIAN NIERENSTEIN . . . . 971 CVII1.-Studies on the Dependence of Optical Rotatory Power on Chemical Constitution. Part 11. The Effect of Position-isomerism and Conjugation on Optical Activity among Aryl Derivatives of Amino- and Bisimino-camphor. By BAWA KARTAR SINGH DALIP SINGEJ GURU DUTT and GOPAL SINGH . . 980s C1X.-Ortho-para-isomerism in the Preparation of Diamino-diphenylmethane. By HAROLD KING. . . 988 CX .-Experiments on Halogenation. The Direct Displacement of Negative Groups by Halogen in the Aromatic Series. Yart I. The Displacement of the Nitro-group by Bromine. CX1.-Some Nitro-derivatives of Naphthalene and Anthra-CXI1.-The Action of the Grignard Reagent on Aromatic CXII1.-The Electro-affinity of Aluminium.Part 111. The By JAROSLAV CXIV.-The Nature of the P-Ferricyanides and the /3-Ferro-By RICHARD VERNON WHEELER . . 903 tion Equilibria. By ALEC DUNCAN MITCHELL . . 957 By SURENDRA NATH DHAR . . . . 993 quinone. By SURENDRA NATF DHAR . . . 1001 Nitro-compounds. By HARRY HEPWORTH . . 1004 Acidity and Constitution of Aluminic Acid. HETROVSK$ . . 1013' cyanides. By SAMUEL HENRY CLIFFORD BRIQGEI . . 102 X CONTENTS. CXV.-The Cyanine Dyes. Part 11. The Synthesis of o-Aminocinnamylideneyuinaldine Methiodide. By WILLIAM HOBSON MILLS and PERCY EDWIN EVANS . . 1035 CXV1.-The Isomerism of the Oximes. Part IX. 2:4-Dinitrobenzaldoxime and Brorno-substituted Hydroxy- and Methoxy-benzaldoximes. By VERA WENTWORTH and OSCAR LISLE BRADY .. 1040 CXVI1.-The Constitution of Carbamides. Part XI. The Mechanism of the Synthesis of Urea from Ammonium Carbamate. The Preparation of certain Mixed Tri-substituted Carbamates and Dithiocarbamates. By EMIL ALPHONSE WERNER . . 1046 CXVII1.-A Comparative Study in the Xanthone Series. Part T. By SURENDRA NATH DHAR . . . . 1053 CX1X.-Complex Metallic Ammines. Part IV. cis-Sulpho-acetato- cis-Methionato- and cis-Dimethylmalonato-di-ethylenediaminecobaltic Salts. By THOMAS SLATER PRICE and JAMES COOPER DUFF . . . 1071 CXX.-The Constitution of Carbamides. Part XII. The Decomposition of Urea when Heated in Solution in the Presence of Acids. By EMIL ALPHONSE WERNER . 1078 CXX1.-Synthesis of Boranilides. Part I. Boranilide and CSXI1.-The Ethylene-Oxide Structure of Sucrose and some other Carbohydrates.Ey EDWARD FRAXKLAND ARMSTROXG and THOMAS PERCY HILDITCH . . 1086 CXXIIL-Triethylene Tri- and Tetra-sulphides. By Sir PRAFULLA CHANDILA RAY . . 1090 CXX1V.-The Oxidising Properties of Sulphur Dioxide. Part I. Iron Chlorides. By WILLIAM WARDLAW and FRANCIS HERBEBT CLEWS. . . 1093 CXXV.-The Hydrolysis of Platinum Salts Part I. Potassium Platinichloride. By EBEN HENRY ARCHIBALD . . 1104 CXXV1.-Studies in Catalysis. Part XIV. The Mechanism of the Inversion of Sucrose. By CATHERINE MARGARET JOSES and WILLIAM CUDXORE MCCULLAGH LEWIS . . 1120 CXXVI1.-The Preparation of Guanidine by the Interaction of Dicyanodiamide and Ammonium Thiocyanate. By EMIL ALPHONSE WERNER and JAMES BELL . . 1133 CXXVII1.-The Synthesis of some Nitro-derivatives of Toluene.By OSCAR LISLE BRADY and PERCY NOEL WILLIAXS . 1137 CXX1X.-Studies in Ring Formation. Part 111. The Coii-densation of Aromatic Amines with a- and /3-Diketones and with 4 4’-Diacetyldiphenyl. By CLARENCE VICTOR FERHISS and EUSTACE EBENEZER TURNER . . 1140 PAGE its Derivatives. By TARINI CHARAN CHAUDHURI . . 1081 CONTENTS. xi PAGE CXXX.-The Constitution of Catechin. Part 11. By MAXI-MILIAN NIERENSTEIN . . 1151 EMIL FISCHER MEMORIAL LECTURE. By Dr. M. 0. FORSTER, F.R.S. . . 1157 CXXX1.-Studies in Substituted Quaternary Azonium Com-pounds containing an Asymmetric Nitrogen Atom. Part 111. Resolution of Phenylmethylethylazonium Phenyl-benzylpropylazonium and Phenylbenzylallylazonium Iodides into Optically Active Components.By BAWA KARTAR SINGH . . 1202 CXXXI1.-The Preparation and Characterisation of Ethylene-bromohydrin. By JOHN READ and REXFORD GEORQE HOOK 1214 CXXXII1.-The Propagation of Flame in Mixtures of Methane and Air. Part 11. Vertical Propagation. Part 111. Propagation in Currents of the Mixtures. By WALTER MASON and RICHARD VERNON WHEELER . . 1227 CXXX1V.-The Oxidising Properties of Sulphur Dioxide. Part 11. Iron Phosphates. By WxLrufii WARDLAW, SIDSEY RAYMOND CARTER and FEANCIS HERBERT CLEWEI . 1241 CXXXV.-The Alcohols of the Hydroaromatic and Terpene Series. Part 111. isoPulego1. By ROBERT HOWSON PICKARD HAROLD HUNTER WILLIAM LEWCOCK and HANNAH SMITH DE PENNINGTON . 1248 CXXXV1.-Some New Azopyrazoloncs and Allied Compounds.By KENNETHERBERT SAUNDERS . . 1264 CXXXVI1.-The Action of Aminee on Trinitrophenylmethyl-nitroamine. By THOMAS CAMPBELL JAMES JAMES IVOR MORGAN JONES and ROBERT TLLTYD LEWIS . . 1273 CXXXVII1.-The Influence of Hydrogen Sulphide on the Occlusion of Hydrogen by Palladium. Part 11. By EDWARD BRADFORD MAXTED . . 1280 CXXX1X.-Catalysis in the Hydrolysis of Esters by Infra-red Radiation. By ERIC KEIGHTLEY RIDEAL and JAMES ARTHUR HAWKINS . . 1288 CXL.-The Action of Chlorine on 3 5-Dichloro-1 l-dimethyl-A2:4-cycZohexadiene. By LEONARD ERIC HINKEL . . 1296 CXL1.-The Effect of Asymmetry. A Study in Crystal Structure. By THOMAS VIPOND BARKER and MARY WIN-EARLS PORTER . . 1303 CXLII. -Studies on Hypophosphorous Acid. Part 11. Its CXLII1.-Modification and Extension of the Friedel and CXL1V.-The Freezing Point of Wet Benzene and the Influence Reaction with Iodine.By ALEC DUNCAN MITCHELL . . 1322 Crafts’ Reaction. Part I. By JRANENDRA NATH RAY . 1335 of Drying Agents. By NEvrL VINCENT SIDGWICR . . 134 xii CONTENTS. CXLV.-Studies in the Acenaphthene Series. Part I. The Conversion of o-Nitroamines into iso-Oxadiazole Oxides. By FREDERICK MAURICE ROWE and JOHN STANLEY HERBERT DAVJEB . . 1344 CXLV1.-Diethylerietriamine and Triethylenetetramine. By ROBERT GEORGE FARGHER . . 1351 CXLVI1.-The Constitution of Carbamides. Part XIII. The Constitution of Cyanic Acid and the Formation of Urea from the Interaction of Ammonia and Cyanic Acid at Low Temperatures. By EMIL ALPHONSE WERNER and WILLIAM ROBERT FEARON . . . 1356 CXLVII1.-The Chemistry of Polycyclic Structures in Relation to their Homocyclic Unsaturated Isomerides.Part I. Some Derivatives of cycZoPentene and clicycZoPentane. By ERNEST HAROLD FARMER and CHRISTOPHER KELK INGOLD . 1362 CXL1X.-A New Type of Compound containing Arsenic. By GEORGE JOSEPH BURROWS and EUSTACE EBENEZER TURNER . 1373 CL.-Derivatives of Phenyldihydroresorcin. By ALEXANDER JOEKN BOYD PERCY HERBERT CLIFFORD and MAURICE ERNEST PROBERT . 1383 CL1.-The Electrical Conductivity of Potassium Sodium and Barium Chlorides in Mixtures of Pyridine and Water. By JNANENDRA CHANDRA GHOSH . . 1390 CLIL-The System Benzene-Ethyl Alcohol-Water between + 25" and -5'. By NEVIL VINCENT SIDGWICR and WILLIAM JAMES SPURRELL . . 1397 CLII.1.-The Catalytic Action of Iodine in Sulphonation.Part I. By J~~ANENDRA NATH RAY and MANIK LAL DEY . 1405 CL1V.-The Resolution of the Keto-dilactone of Benzophenone-2 4 2' 4'-tetracarboxylic Acid. By WILLIAM HOBSON MILLS and CHARLES REYNOLDB NODDER . . 140'7 CLV.-The Preparation and Physical Properties of Carbonyl Chloride. By RALPH HALL ATKINSON CHARLES THOMAS HEYCOCK and SIR WILLIAM JACKSON POPE . . 1410 CLV1.-0- and p-Tolueneazoglyoxalines. By FRANK LEE PYMAN and LEONARD ALLAN RAVALD . 1426 CLVI1.-The Sulphonation of Glyoxalines. By FRANK LEE PYMAN and LEONARD ALLAN RAVALU . . 1429 CLVII1.-The Velocity of Decomposition of High Explosives in a Vacuum. Part I. By KOBERT CROSBIE FARMER . 1432 C1LIX.-The Preparation of Pure Carbon Dioxide. By ROBERT CROSBIE FARMER . . 1446 CLX.-Triphenylarsine and Diphenylarsenious Salts.By SIR WILLIAM JACKSON POPE and EUSTACE EBENEZER TURNER . 1447 PAG ... CONTENTS. x111 1'AG E CLXI. -Interaction of Ethylene and Selenium Monochloride. By HAROLD WILLIAM BAUBOR CHARLES STANLEY GIBSON, and SIR WILLIAM JACKSON POPE . . 1453 CLXI1.-Researches on Residual Affinity amd Co-ordination. Part 11. Acetylacetones of Selenium and Tellurium. By GILBERT T. MORGAN and HARRY DUGALD KEITH DREW . 1456 CLXII1.-The Formation and Reactions of Imino-compounds. Part XX. The Condensation of Aldehydes with Cyano-acetamide. By JAMES NELSON EDMUND DAY and JOCELYN FIELD THORPE . . 1465 CLXIV.-The Constitution of Polysaccharides. Part I. The Relationship of Inulin to Fructose. By JAMES COLQUHOUN IRVINE and ETTIE STEWART STEELE .. 1474 ULXV.-The Constitution of Polysaccharides. Part 11. The Conversion of Cellulose into Glucose. By JAMES COLQUROUN IRVINE and CHARLES WILLIAM SOUTAR . . 1489 CLXV1.-The Influence of Lead on the Catalytic Activity of Platinum. By EDWARD BRADFORD MAXTED . . 1501 CLXVI1.-The Investigation of Sodium Oleate Solutions in the Three Physical States of Curd Gel and Sol. By MARY EVELYN LAING and JAMES WILLIAM MCBAIN . . . 1506 CLXVII1.-A New Method for the Preparation of 2 :4-Di-hydroxy- and 2 4 4'-Trihydroxy-benzophenone and some Observations relating to the Hoesch Reaction. By HENRY STEPHEN . . 1529 CLX1X.-Studies in tho Coumaranone Series. Part I. The Preparation of 4- 5- and 6-Methylcoumaran-2-ones and some Derivatives of 0- m- and p-Tolyloxyacetic Acids.By LUCY HIWINBOTHAM and HENRY STEPHEN . . 1534 CLXX.-Carbazole-blue and Carbazole-violet. By MAURICE COPISAROW. . . 1542 CLXX1.-The Cganine Dyes. Part 111. The Constitution of Pinacyanol. By WILLIAM HOBSON MILLS and FRANCES MARY HAMER . . 1550 CLXXI1.-The Coagulation of Gold Hydrosols by Electrolytes. The Change in Colour Influence of Temperature and Reproducibility of the Hydrosol. By J~ANENDRA NATH MUKHERJEE and BASIL CONSTANTINE PAPACONSTANTINOU . 1563 Part I. The ar-Dihydro-a-naphthylamines and their Derivatives. By FREDERICK MAURICE ROWE and ESTHER LEVIN . . 1574 CLXX1V.-The Formation and Stability of spiro-Compounds. Part 111. spiro-Compounds from cycZoPentane. By OSCAR BECKER and JOCELYN FIELD THORPE . . . 1579 CLXXII1.-Studies in the Dihydronaphthalene Series xiv CONTENTS. PAGE CLXXV.-Disodium Hydrogen Phosphate Dodecahydrate. By D A ~ I E L LLEWELLYN HAMMICK HECTOR KENNETH GOADBY, and HENRY BOOTH . . 1589 CLXXV1.-The Preparation of Ethyl Iodide. By BEATRICE ELIZABETHA HUNT . . 1592 CLXXVIL-Studies in the Ohroman Series. Part I. By ANNIE GREENWOOD and MAXIMILIAN NIERENSTEIN . * 1594 CLXXVI JI. -S tudies on the Dependence of Optical Rotatory Power on Chemical Constitution. Part 111. 1 4-Naphthylenebisiminocamphor. By BAWA HARTAR SINGH and MAHAN SINGH . . 1599 CLXX1X.-The Permeability of Glass to Iodine and Bromine Vapours. By JAMES BRIERLEY FIRTH . . 1602 CLXXX.-The Velocity of Decomposition of High Explosives in a Vacuum. Part 11. Trinitrophenylmethylnitroamine (Tetryl). By ROBERT CROSBIE FARMER . . 1603 CLXXX1.-The Formation of 2 3 6-Trinitrotoluene in the Nitration of Toluene. By ROYSTON BARRY DREW . . 1615 CLXXXI1.-Hgenanchin and other Constituents of Hyenanche globosa. By THOMAS ANDERSON HENRY . . 1619 OBITUARY NOTICES . . 162

ISSN:0368-1645    

DOI:10.1039/CT92017FP001

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

4 TAYLOR THE CHLOROACETATES OF 11.-The Chloroacetates of S-AIkylthiocarbamides. By JOHN TAYLOR. IN a previous communication (T. 1917 111 650) the theory was advanced that salts of S-alkylthiocarbamides have a sulphonium structure (NH,),C:SRX where R is an alkyl group and X an acidic residue. The possibility of the existence of ammonium and of carbonium forms XNH,-C(:NH)=SR and (NH,),CX*SR was considered. The behaviour of the nitrites and thiocyanates of these com-pounds points to the improbability of an ammonium structure, whilst the ready ionisation of the salts points to the non-existence of carbonium structure. Occasionally in the presence of strong acids a second form of a salt is obtained differing considerably from that separating from a neutral solution. This second form is unstable being readily converted into the first by recrystallisa-tion from hot water.It was conjectured that this unstable form is of the ammonium type its instability being paralleled by the instability of the salts of amides. A study of the chloroacetates of S-alkylthiocarbamides and in particular of the monochloroacetates confirms the view that the salts have not an ammonium structure. They are readily prepared by mixing a concentrated aqueous solution of thiocarbamide methyl nitrate or of thiocarbamide benzyl chloride with a solution of the sodium salt of the required acid, when the new compound separates from solution S- ALKYLTHIOCARBAMID ES . 5 To the general rule that a thiocarbamide results from the inter-action of a thiocarbimide and a primary or a secondary amine, there is one tolerably well-marked exception namely when the radicle of either contains a halogen constituent.In this case, although the primary union may run the normal course there follows the production of a salt of a cyclic base in which the carbon atom originally halogenated is now attached t o sulphur thus : R*NCS + NH,*CH,*C H,Br + R*N R*CS*NH*CH,*CH,Br -+ 7 ,HEr,* RN:Y-NH*CH;C R, (Gabriel Ber, 1889 22 1148). CH,Br*CHBr*CH,*NCS + PhNH -+ PhN:Q--Similarly, CH,Br*CHBr*CH,-NH*CS*NHPh + '? ,HBt* NH*CH,* CH,. CH,Br (Dixon T. 1897 71 617). A similar behaviour is shown by halogen-substituted acylthiocarbimides : CH,Cl*CO*NCS + C,HT*NH2 + C;H;*NH*CS*N H*CO*CH,Cl -> C,H,*N:F--S N H - C O ~ H ,KC1* (Dixon Zoc.c i t . ) . The same change results when an already formed non-halogenated thiocarbamide has halogen introduced into its molecule: 1 CH2:CH*CH2*NH*CS*NH -+ CH21*CHI*CH~.NH.CS=NH -+ '? ,HI* N H F --NH*CH,- C€I* CH,I (Dixon T. 1896 69 25). Only two exceptions to this rule appear to exist namely, (1) where halogen is attached t o an aromatic radicle thus the compound C,H,Cl-NH-CS*NH is quite stable (Losanitsch Ber., 1872 5 ISS) and (2) where halogen is par& of an unsaturated radicle ; thus the compound CH,:CCl=CH,*NH*C&*NH does not yield a cyclic compound (Henry Ber. 1872 5 188; Dixon T., T t is clear from these'examples that there is in thiocarbamides, a very strong tendency towards the conversion of bivalent into quadrivalent sulphur when t.here is present a halogenated radicle not already linked to sulphur.1901 79 553). * These formulai? are written as the authors themselves gave them. The present author:prefersIto represent them as sulphonium compounds 6 TAYLOR THE CHLOROACETATES OF If thiocarbamide methyl monochloroacetate had an ammonium structure that is CH,Cl*CO,-NH,*C( :NH)*SMe there would follow the formation of a cyclic compound, NH ?-- YMeCl N H,*O*CQ CH Such a union occurs as the initial stage of the formation of thetines. This compound would have its chlorine highly ionised it would respond to Andreasch’s test for thiolacetic acid (Ber. 1879 12, 1385) and further the chloroacetate group being now divided into two parts could not be displaced wholly by another acid group.Thiocarbamide methyl chloroacetate prepared as described, agrees in no respect with these properties. Its aqueous solution does not yield silver chloride on the addition of silver nitrate no purple colour is observed on applying Andreasch’s test hence the compound does not contain the grouping *CO*CH,*S* and lastly, the picrate is identical with that obtained from thiocarbamide methyl nitrate consequently the whole of the chloroacetate group has been displaced by the picrate residue. It is thus highly probable that the chloroacetate group is not attached t o nitrogen and that since ring closing does not occur, the chlorine forms part of a group already linked to sulphur which is already exerting its full valency and therefore does not admit of further combination.The structure of thiocarbamide methyl chloroacetate would appear to be represented by the formula (NH,),C SMe*O*CO* CH,Cl, in agreement with that proposed for other salts of S-alkglthio-carbamides and would correspond with its properties as described above. That the chlorine of the chloroacetate residue would combine with sulphur if opportunity occurred is shown by the fact that, when this substance is heated in alcoholic solution with thiocarb-amide isothiohydantoic acid results. This is due to the initial formation of an additive compound of the original substances, (NH,),C:SMe*O*CO-CH,Cl+ CS(NH,) -+ (NH,),C SMea CO*CH,*SCl:C(NH,),, which readily loses hydrogen chloride. The acid in turn decom-poses the methyl-$-thiourea ester of isothiohydantoic acid leaving free isothiohydantoic acid, (NH,)2C:SMe*O*CO*CH,*S*C( :NH) *NH -+ HCI (NH2)zC SMeCl + CO,H*CH,*S*C( :NH) *NHz S-ALKYLTHIOCARB AMID E S.7 When thiocarbamide benzyl chloroacetate instead of the methyl compound is combined with thiocarbamide loss of hydrogen chloride alone foliows and the benzyl-$-thiourea ester of isothio-hydantoic acid is obtained showing that the reaction proceeds in the manner suggested. Attempts to remove hydrogen chloride alone from thiocarb-amide methyl chloroacetate by the use of dilute alkali or of pyridine were quite unsuccessful. No indication of the formation of a glycine derivative was observed ; the whole of the chloroacetate group was removed and the resulting +-thiourea decomposed. Thiocarbamide and methyl chloroacetate unite additively on long contact in acetone solution.The product is isomeric with the thiocarbamide methyl chloroacetate previously described. There are many points of difference between the two substances; thus the additive compound is readily soluble in water and the solution is acid due to the formation of hydrochloric acid. When boiled in alcoholic solution it loses methyl alcohol and the hydro-chloride of isothiohydantoic acid separates on cooling. With less than one equivalent of sodium hydroxide both methyl alcohol and hydrochloric acid are lost and isothiohydantoin is obtained. The substance also readily responds t o tests for thiolacetic acid. These reactions are in sharp contrast with those previously described for thiocarbamide methyl chloroacetate and point to the additive compound being the hydrochloride of meth?/b isothio-h ydan t oa t e (NH,),C SC1* CH,.C0,Me. E thy1 chloroacet ate com-bines similarly with thiocarbamide . Dichloroacetates and trichloroacetates of 8-alkylthiocarbamides were also prepared. In general properties they closely resemble the monochloroacetates with the exception that they are inert towards thiocarbamide. EXPERIMENTAL. Thiocarbamide methyl monochloroacetate is precipitated when to a concentrated aqueous solution of thiocarbamide methyl nitrate is added an excess of a concentrated aqueous solution of sodium monochloroacetate. On crystallisation from alcohol it forms prisms which decompose at about 1 5 7 O . Its aqueous solution is neutral and furnishes a picrate melting a t 22O0 identical with the picrates from other salts of S-methylthiocarbamide.The monochloroacetate responds to the usual tests for S-metliylthio-carbamides; an alkaline solution of lead acetate gives lead mercaptide and an ammoniacal solution of silver nitrate gives silver mercaptide and silver cyanamide no silver chloride being formed 8 TAYLOR THE CHLOROACETATES OF Found N=15.01 and 100 parts gave 168 parts of silver as C4H,0,N2C1S requires N = 15-17 per cent. and 100 parts require 175 par& of silver. When the solid was heated with one equivalent of pyridine, methyl mercaptan escaped. Addition of one equivalent of N-sodium hydroxide to a dilute solution of the substance did not cause a precipitation of methyl-$-thiourea.When the alkaline solution was acidified with chloroacetic acid and then evaporated, the original substance was recovered. Attempts were made at various stages to obtain a copper derivative of glycine but quite unsuccessfully . Thiocarbamide benzyl monochloroacetate was prepared similarly from thiocarbamide benzyl chloride and sodium monochloroacetate. Water and alcohol each dissolve the substance readily but it is sparingly soluble in a solution of sodium monochloroacetate. The usual reactions of a $-thiourea are given and it yields a picrate which melts a t 183O. AgSMe and Ag,CW,. Decomposition occurs on heating to 156O. Found C1=13*4; N=10.65. CSH,,O,N,CIS requires C1= 13.63 ; N = 10.74 per cent. Attempts to prepare sulphonium and ammonium forms of this compound were unsuccessful.Renzyl-$-thiourea dissolved in chloroacetic acid gave an uncrystallisable syrup. The ammonium form of thiocarbamide benzyl sulphat,e on treatment with an acid solution of sodium monochloroacetate yielded the same product as the sulphonium form gave when treated with a slightly alkaline solution of the same salt. Both were identical with the compound already described and decomposed at the same temperature, namely 157Oi Thiocarbamide methyl monochloroacetate and Thiocarbamide. -Alcoholic solutions of these substances in nearly equivalent pro-portions (the thiocarbamide in slight excess) were heated together on a steam-bath. After a short time .the liquid originally clear, became turbid and a white amorphous solid separated which con-tained chlorine and when heated with an alkaline solution of lead acetate gave first lead mercaptide and on prolonged heating lead sulphide.It responded also to Andreasch’s test for thiolacetic acid, thus showing the formation of a derivative of isothiohydantoic acid. The mother liquors gave a strong reaction for $-thiourea. Analysis of the first product gave no decisive figures and indicated a mixture. After the solid had been further heated with a further quantity of alcohol the $-thiourea reactions became very faint S-ALKYLTHIOOARBAMIDES. 9 The analysis and general properties of the solid now showed it to be rather impure isothiohydantoic acid. The substance chars at about 205O (Found N = 20- 1 ; S = 23.1. c:,H,O,N,S requires N=20*9; S=23-88 per cent.).Thiocarbamide b enzyl monochloroacetate and Thiocarbamide. -Combination was effected as in the preceding case. The pro-duct free from chlorine gave a strong reaction for $-thiourea and responded to the tests for thiolacetic acid. It decomposed on heat-ing to 190°. Analysis showed that the components had united with loss of hydrogen chloride and that little if any further decomposition had occurred. The substance may be regarded as the benzyl-$-thiourea ester of isothiohydantoic acid. Found N = 18.77 ; S = 20.9. Cl,Hl,0,N,S2 requires N = 18.6 ; S= 21.3 per cent. An attempt to prepare the real additive compound by allowing the materials to remain together in cold acetone solution for several days resulted in the isolation of a solid containing C1= 5.7 instead of 10.6 per cent.required by the additive compound. Thiocarbamide and Methyl monochloroacetate.-Direct addition of these substances was effected by allowing equivalent weights, mixed in acetone solution to remain for two days. Colourless crystals which decomposed a t 200° separated from the solution. The crystals readily dissolved in water and gave a strongly acid solution. The picrate decomposes a t 175O. When the compound was heated with an alkaline solution of lead acetate no trace of mercaptdde was observed but lead sulphide formed readily. Silver nitrate gave a white precipitate which was soluble in ammonium hydroxide. The ammoiiiacal solution did not yield mercaptide or sulphide when heated thus indicating the formation of a silver compound of isothiohydantoic acid.A purple coloration in Andreasch’s test proved the presence of the group *CO*CH2* So. Hence the compound is the hydrochloride of methyl isothio-hydantoat e. Found C1= 19-4. On boiling with alcohol it was hydrolysed to the hydrochloride of isothiohydantoic acid (Found C1= 23.28. Calc. C1= 22-86 per cent.). When rather less than one equivalent of sodium hydroxide was added to an aqueous solution of the original compound prisms, recognised as isothiohydantoin (Found S=27-39. Calc. S=27-58 per cent.) separated from solution. The substance decomposed a t 220O. Thiocar b amide and Et hy 1 monoc hloroac etat e .-These substances C4H,0,N,C1S requires C1= 19.2 per cent. B 10 THE CHLOROACETATES OF S-ALKYLTHIOCARBAMIDES. were combined by a similar method to the above.The products separated in glassy six-sided pyramids which dissolved in water, giving an acid solution. It melts a t 107O and decomposes a t about 1200. Found C1= 17-54. C,H1,O2N,C1S requires C1= 17-63 per cent. Thiocarbamide methyl dichloroacetate was precipitated on mix-ing concentrated aqueous solutions of thiocarbamide methyl nitrate and sodium dichloroacetate. White crystals were obtained on crystallising the substance from alcohol. The substance showed all the usual reactions of methyl-$-thiourea and none of isothio-hydantoin. It decomposes a t 165O. Found C1= 32.01. C4H80,N,CI,S requires Cl= 32.4 per cent. Heating with even deficit of alkali caused the evolution of mercaptan. No sign of further combination was observed after the substance had been heated for several hours in alcoholic solu-tion with thiocarbamide.Thiocarbamide benzyl dichloroacetate was prepared similarly. No striking peculiarity was observed in its behaviour. It decom-poses a t 153O. Found N=10.2. C,,H,,O,N,Cl,S requires N = 9.6 per cent. Thiocarbamide methyl trichloroacetate crystallised in shining leaflets on mixing aqueous solutions of thiocarbamide methyl sulphate and sodium trichloroacetate. Its behaviour was that of an ordinary salt of methyl-$-thiourea. Heating with pyridine caused complete decomposition and on being heated alone it decom-posed a t 187O. 'One hundred parts of the substance gave 124.2 parts of silver whereas 100 parts of C,H,O,N,Cl,X require 127.4 parts of silver. Thiocarbamide benzyl trichloroacetate was prepared similarly. It resembled the preceding compound in appearance and behaviour and decomposed at 150O. An identical product was obtained by heating together benzyl-$-thiourea and trichloroacetic acid. C,,H,,O2N2Cl3S requires N = 8-45 ; C1= 32.3 per cent. Alcoholic solutions of this compound were heated for several hours with one two and three equivalents respectively of t.hio-carbamide but no indication of the formation of isothiohydantoin Found N = 8-52 ; C1= 31.4 HEYROVSEP :~ELECTROAFFINITY OF ALUMINIUM. PART I. 11 derivatives was observed. The residue from the evaporation of the alcoholic solution also failed to indicate the presence of isothio-hydantoin but reacted freely for +-thiourea. TEE CHEMISTRY DEPARTMENT, UNIVERSITY COLLEGE, CORK. [Received December lst 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700004

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

HEYROVSEP :~ELECTROAFFINITY OF ALUMINIUM. PART I. 11 III[.-y'he h'leclroafinity of A lwminiufir. par$ 1. Y'he Ionisation and H yily*olysis of A lurniniurn Chloride. By JAROSLAV HEYROVSK~. ALUMINIUM chloride is a quaternary strong electrolyte exerting a fourfold osmotic pressure in dilute solutions. I n a solution there may exist the ions AlCl,' AlCl" Al"' and C1'. There is no evidence for the existence of complexes such as (AlC13)2; the single molecules seem to possess more affinity for water than for each other. The cations combine to a certain degree with the hydroxyl ions to form AlCk-OH AlCl(OH), and Al(OH),; as however this hydrolysis does not exceed 3.8 per cent. even in the most dilute solutions concerned it will first be neglected in considering the dissociation of aluminiuni chloride.Let the concentration of aluminium chloride in gram-equivalents per litre be denoted by c and that of the chloridions resulting from the dissociation be cx (where x is less than 1). Let the concentration of the Al"' cations expressed in gram-cations per litre be further let [Al'"] = * Y3 (Y,<Q)> [*1C1,'1 = c * Yl (Y1<3) and [*1C137 = c Yo (YO<*). [AlCl'.] = c . y2 (pa<+) Then We shall first consider how the dissociation would change with dilution if the law of mass action were valid 12 HEYROVSK+ ELECTROAFFINITY OF ALUWNIUM. PART 1. which gives yz = K . cx . y3 y1 = K R 2 . (cx)' . ~3 yo = K,K,K? * * y3' Substituting in equation (l) we get ~ J ~ { K . K ~ K ( C X ) ~ + K,K,(cx)~+ K,CX + l } = 33 Similarly Since x==y1+2y,+3y3 .. . . . . . ( a ) when c becomes great x approaches zero and therefore yl approaches zero YZ 7 9 ) ?/3 7 7 7 7 And from (l) yo approaches 4 (a maximum). As c approaches zero x approaches unity; it therefore follows from the above equations that y3 approaches 4 (a maximum), yl y2 and yo approach zero. We can find the maximum values of y1 and y2 as follows: Therefore By equating t o zero we find that yz is a ma.ximum when x=-: Similarly we may show that' and therefore y1 is a maximum when x = - ) i . Summing up, yo is a maximum when c is great and x is small and a minimum when c is very small and x = 1 HEYROVSK* ELECTROAETINITY OF ALUMINIUM. PART I. 13 y1 is a maximum when x = Q and a minimum when c is very y2 is a maximum when x=$ and a minimum when c is very y3 is a maximum when c is very small that is when x = 1 and The changes of yl ye y3 and x corresponding with the gradual This was deduced for an ideal electrolyte obeying the law of great or very small that is when x=O or x=1.great or very small that is when x=O or x=1. a minimum when c is very great that is when x = 0. splitting into simpler ions on dilution are plotted in Fig. 1. Fx. 1. 7 3 0Y i 0 mibas action. It can however be shown that the ,same mode of dissociation takes place a.s indicated in Fig. 1 whatever the law may be so long as it is of the general form = K . Cation x C L o n C:,Olt!Cllle ~~ (For van't Hoff's constant a= b = $ p ; for Ostwald's a= b =I).) progression we obtain Thus assuming that the indices a b c .. . are in arithmeti 14 HEYROVSd ELECTROAFFINITY OF ALUMINIUM. PART I. which means that y2 is a maximum when x = 3 just as in the previous case and similarly for y1 and ys. The coefficient x representing the ionised fraction of chlorine, may be determined from the potential of a calomel electrode filled with the respective aluminium chloride solution. These results however would give only the maximal and minimal value of y3 that is of the dissociation into Al"' ions but no evaluation whatever as to y and y2. Further conclusions respecting the [Al' ''1 concentration can be drawn from the hydrolysis of aluminium chloride solutions when solid aluminium hydroxide is present. Then [Al"'] . [OH/]3= K , the concentration of [OH/] being determinable by the potential of a hydrogen electrode.To evaluate the remaining ionic concentrations specific con-ductivit]ies of aluminium chloride solutions must be considered. Measurements of Electromotive Force. Measurements of cells of the type Hg J calomel solution of AlCl I Hz(Pt) were made with all precautions in the manner described by Tol-man and Ferguson ( J . Amer. Chem. SOC. 1912 34 232) and Acree (Amer. Chem. J. 1911 46 585 621 638) using platinised glass electrodes. Readings on the potentiometer could be made t o a tenth of a millivolt. In order t o examine the reproducibility of the electrodes used, the cell was filled with 0.100N-hydrochloric acid. The E.M.F. a t 18O and 760 mm. was found to be constant for three days a t 0.3958 f 0*0003 volt.The mercury used was purified and twice redistilled. The hydrogen was passed through alkaline permanganate and lead nitrate solutions and was finally bubbled through the same solu-tion as was being measured in the cell. The aluminium chloride was purified by precipitation three times from solution by means of hydrogen chloride and the solutions were kept a t 2 5 O in bottles the corks of which were covered with paraffin. The cell was kept in a thermostat at 2 5 O and the readings were repeated after three or four weeks. The effect of barometric change was much less than the variations due t o experimental errors which became appreciable in dilute solutions. Two hydrogen electrodes were used simultaneously dipping into the same solution; they did not differ by more than 0.5 millivolt HEYROVSKP ELECTROAFFINITY OF ALUMINIUM.PART I. 15 In this way the following results were obtained for the cell: +Hg I (Hg,Cl solid) AlC1 solution 1 H,(Pt) -Concentration in gram-equiv. per litre. of AICI, 2.29 0-368 0.0184 0.0092 0.006 13 0-0046 0.00306 E.M.F. observed at hfferent times. L c I 0.3739 0-3735 0.3725 0.3725 0.4810 0.4810 0.4808 0.4807 0.6000 0-6005 0-5930 0.5924 0.6190 0.6186 0.6170 -0.632 - 0.634 -0.639 0.646 0.643 0.641 0-659 0.658 0.661 0.655 Mean E.M.F. in volt. 0.373 0.481 0.595 0-618 0.633 0.643 0.658 I n other experiments the aluminium chloride solutions were shaken with precipitated aluminium hydroxide for several weeks previous to being introduced into the cell.With these solutions, the following results were obtained : Concentration of AlCl, solutions .in gram - equiv. per litre. 2-88 0.934 0- 1845 '0.0675 0.0337 0.02134 0.01067 0-00675 0.002 13 E.M.F. observed at different times. r 0,4221 04225 0.4940 0-4934 0.5351 0.5623 0.5804 0.5965 0.5980 0.6147 0.6158 0.6376 -0.6685 -, 0.4218 -0:4939 0.4934 0.5359 0.5614 0.5818 0.5807 0.5981 0-5996 0-6360 0.632 0.6667 - -Mean E.M.F. in volt. 0.4222 0.4937 0.5355 0-5620 0.5813 0.5984 0-6150 0.635 0.668 I n order t o find the potentials of the single electrodes the aluminium chloride-calomel electrodes were compared with normal and tenth-normal calomel electrodes at 2 5 O .Saturated half-saturated and quarter-saturated potassium chloride solutions were used successively as intermediate solutions and the values extra-polated. This method of eliminating the liquid potential was found to be much more trustworthy than the use of potassium nitrate or ammonium nitrate solutions. All glass tubes were a t least 0.5 cm. wide and no glass taps were used. The following values were found for the potential 7rN of the electrode. Hg I (Hg2Cl,)A1Cl solution taking the normal calomel electrode as zero 16 HEYROVSKP ELECTROAFFINITY OF ALUMINIUM. PART I. Concen-tration of AICl,. 2-29 0.368 0.0409 0-01 84 0.0092 0.006 13 0.00460 0.00306 Quarter half and fully saturated potassium chloride solution as intermediate solution. - P.D.against P.D. against TK N-calomel electrode. N/10-calomel electrode. extra- - polated. -0.0090 -0.0114 -04137 -0.0615 -0.0625 -0.0664 -0.0140 +0.0294 0.0282 0.0278 - 0.0249 - 0.0252 - 0.0267 + 0.0273 0.0766 0.0768 0.0772 .+ 0.0238 0.0238 0.0234 +0*0772 0-0970 0.0976 0.0978 0.0444 0.0444 0.0444 + 0.0986 0-1174 0-1168 0.1155 0.0636 0.0634 0-0633 fO.1150 0.1257 0.1255 0.1253 0.0721 - -(-0*1250 - + 0.1320 0.1352 0.1328 0-1320 - - - 0.1420 0.1420 0.0868 0.0870 0.0880 +0*1420 Similarly the values of 7rN of calomel electrodes filled with aluminium chloride solutions saturated with aluminium hydroxide were obtained : P.D. against N-calomel electrode using qmrter hdf and fully saturated Concentration potassium chloride solution. RK h of AlCI,. r- \ extrapolated.2.88 -0.0105 -0.0132 -0.015 -0.017 0.934 + 0.0106 0.0092 0.0076 + 0.007 0.0675 +0*0721 0.0720 0.0710 + 0.070 0.00675 +0*1185 0.1180 0-1172 +0*117 For the calculations of conductivities Jones' data (Carnegie Inst. Publ. No. 170) which agree with those of Ley (Zeitsch. physikal. Chem. 1899 30 206) were used. Molecular Dilution u Molecular Dilution 97 conductivity 1 mol. in conductivity 1 mol. in nt 25". u litres. I at 25". u litres. 220.86 360.56 1024 265.12 3; 381.44 2048 308.80 128 393.79 4096 193.51 4 ' 341 -24 512 Calculation of Dissociation.. The single potentials rN were plotted against logc and the values of 7rN for use in the following calculations were taken from the smooth curve. The concentrations of chloridions were found in the following way.I f 7rN were the potential of a calomel electrode in a given aluminium chloride solution then the concentration of a potassium chloride solution in which the calomel electrode had this same potential 7rN was found from the curve showing the relation between the potential of a calomel electrode and the logarithm of the concentration of potassium chloride. It was assumed that the concentration of chloridions in these two solutions was the same HEYROVSK$ ELECTROAFFINITY OF ALUMINIUM. PART r. 17 and the absolute value of the chloridion concentration was then calculated from measurements of the conductivity of potassium chloride solution. The following values of rN for calomel elec-trodes in potassium chloride solutions were used (Abegg Auerbach, and Luther Abhandl.Bunsen Ges. No. 5 ) : xx of AT- calomel electrode at 25’= 0.000 volt 7 ) N/10- 7 9 7 , 0.0541 ? 7 N/100- ! 9 7 7 0.108’7 7 9 N/1000- ? ,? 7 0.164 Column 3 (table I) was calculated in this way. From this the ratio [ g = x column 4 was obtained. c For example in an 0*0092N-solution of aluminium chloride the potential of a calomel electrode is equal to the potential of a calomel electrode in potassium chloride solution for which logc=3*9114 that is 0.008155N. This being ionised to the extent of 94.6 per cent. has [C1’]=0.007715 which must be identical with the concentration of chlorine ions in an 0.0092iV-solution of aluminium chloride. Hence x = [‘K1=O*838l. C The [Cl’] was not calculated directly from the formula 7r = - 0.0591 10g,,[Cl’], hecause second-class (anionic) electrode potentials do not agree exactly with the values calculated from condudivity data possibly due to the formation of complex mercury ions.Hydrogen electrode potentials however were found t o vary strictly according to the formula r = - 0.0591 log,,C, when the concentration of hydrogen ions C, is determined from conductivity (Bjerrum Zeitsch. physikal. Chem. 1905 53 428; 1907 59 341). Thus column 7 (table I) was calculated from the potential of hydrogen electrode 7~~ (referred to the normal potassium chloride-calomel electrode as zero) the difference of the two normal electrodes having been taken as 0-2837 volt. The ratio cH* (column S) shows the degree of hydrolysis h . For example the potential of a hydrogen electrode in 0*0092X-aluminium chloride solution is - 0.5037 volt 18 HEYROVSKP ELECTROAF-FINITY OF ALUMINIUM.PART I. TABLE I. 1 2 3 4 5 6 7 s 9 c = con-con tration o f AlCI in gram - Maxi-cq uivalent n1r [?!:I ~ 7,. .mum per litre. logl, c. [Cl']. x. x'. in volt. [H']. c YO 0.00306 3.48572 0.00267 0.873 0.835 0.5162 0*000116 0.0378 0.055 0*00460 3.66276 0.00395 0.859 0.829 0.5118 0.000138 0.0300 0.057 0.00613 3.78746 0.00522 0.851 0.825 0.5080 0*0001603 0.0262 0-058 0.00920 :<.96400 0.00772 0.838 0.817 0.5037 0.0001897 0.0206 0.061 0.01585 2.2000 0.01295 0.817 0.803 0.4980 0-0002275 0.0143 0.065 0.02291 2.3600 0.01848 0.806 0.794 0.4937 0.000280 0.0122 0.067 0.03162 2-5000 0.0251 0.793 G.783 0.4900 0.000323 0.0102 0.072 0.05012 2.7000 0.0387 0.772 0.764 0.4850 0.000393 0.00783 0.078 0.1585 i.2000 0.1149 0.725 0-721 0-4710 0.000659 0.0042 0-093 0-480 i.6810 - 0.666 0.664 - - 0.00362 0.112 0-631 I4300 - - 0.646 - -1.2359 0.092 0.7550 0.611 0.607 0.4190 0.00520 0.00421 0.131 2.290 0.3598 1.310 0.572 0.564 0.3870 0.01807 0.00789 0.145 0.00360 -~ ._ .. . . Hence 0.0591 lo,al(,CH- = - 0.5037 + 0.2837 = - 0.2200 volt log c - - o'2200 __- - - 3.722 =- 4.278 lo H a - 0.0591 from which CtT. =0.0001897 h = gH = 0.0206 = 2.06 per cent. As the hydrolysis in the solutions used is less than 3.8 per cent., we may neglect ths concentrations of cations such as AI(OH),' and Al(OH)" and assume or from which it follows that [Al"'] + [AlCl"] + [AlCl,'] + [H'] = [Cl'], 3cy + 2cy + cy1+ c,. = cx, 3Y3f 2?J + ? / l = X - h XI.The values of X I (column 5) are obtained by subtracting the This number XI limits the value of y3 the maximum value of which can be - (when no other cations exist in solution in which case also yo is at a maximum). The minimal value of y3 is X I - 6 in the case when most of the AlC1" cations are formed. I n this way columns 9 10 and 11 were obtained. Considering the difficulty with which second and third ionic charges are acquired the minimal values of y3 are more probable, numbers in column 8 from those in column 4. X' HEYROVSKq ELECTRODFINITY OF ALUMINIUM. PART I. 19 'TABLE I. 10 11 12 13 14 15 16 17 18 19 20 T4qui-valent con-Maxi- Miiii- duc- (L = mum. mum. tivity. A Xti' m'l'.; y3. y3. A,. A . z'' in volt. [H']'.[He]$ y3. y2. y,. 0.278 0.168 120.2 40.9 49.0 as ?TIT. as [H'] 1 0.180 0.142 <.01 0.276 0.162 116.3 40.7 49.3 - - - 0-175* 0*153* -0.276 0.138 113.7 40.5 48.93 - - - 0*170* 0*161* -- 0.160* 0*169'" - 0.272 0.150 110.3 40.0 48.75 - -0.268 0.136 106.0 39.0 49.18 0.503 0.000187 0.811 0.146 0.178 0.009 0.265 0.127 103-0 38.1 47.88 0.4985 0.000207 0.761 0.137 0.187 0.009 0.261 0.116 100.0 36.9 46.8 0.498 0.000227 0.727 0.131 0.188 0.014 0.240 0.054 83.3 27.5 38.14 0.490 0.000323 0.418 0.075 0.2 0-10 0.221 0 - - - 0.487 0.000392 0.248 0.044 0.2 0-13 0.202 0 - - - - -0.188 0 - - - -0.255 0.097 95.3 34.6 45.18 0.4955 0.000260 0.684 0.123 0.19 -- - - - - - - - -- - - -- - - - -* These values are found by extrapolation. I n order to obtain more precise numbers conductivity results have t o be included.Denoting by iM, M, M the mobilities of cations carrying the total charge of one faraday each that is of the ions AlCl,' gAlCl" +Al*** respectively and taking the mobilities of chloridioii as 75.0 and that of hydrion as 365.0 at 2S0 the equivalent conductivity of a solution of aluminium chloride A, is A = 3y3M3 + 2?/,M + ~ l M l + x .75 + h .365, from which A is obtained (column 13) as A =3~3M3+ 2yzM,+ ?/,MI=&- X .75 -h .365. The total charge carried by the three different cations AlCl,', AlCl" and Al"' is cxf faradays and as they contribute to the conductivity the amount A the mean equivalent mobility for one cation is -. Since this value as is evident' from column 14 . approaches 49.2 as the solution becomes very dilute and all the cations become Al"' the number 49.2 has been taken as the most probable equivalent mobility of Al"'.I n order to evaluate the other unknowns more relations are necessary. These are obtained from the most dilute solutions where the third stage of hydrolysis is reached and are supposed t o be in equilibrium with solid aluminium hydroxide the values of rH in pure aluminium chloride solutions and in those saturated A X 20 HEYROVSKP ELECTROAFFINITY OF ALUMINIUM. PART I. with aluminium hydroxide (column 15) coinciding in concentrations less than 0.0lN. I n these solutions, [OH'I3 C?/3 = K,,,,, 7 where KAI,oH)3 denotes the ionic product of aluminium hydroxide. Its value lies according t o the values of y3 between 1.0 and 1.5 x 10-33 (the ionic product of water being taken as 10-14).Further in most dilute solutions yo is negligible so that Y l + Y 2 + Y 3 = 9 . Solving these equations for the three most dilute solutions we get M3=about 30, and the different values of yl y2 and y3 are given in columns 18, The values of y3 in concentrations greater than 0-01N were calculated from the ratio of hydrion concentrations [He]' in solu-tions of aluminium chloride saturated with aluminium hydroxide to [H'] in solutions of aluminium chloride alone. In column .17 a denotes the ratio of the cube of [H']' obtained from the potential 7rE' of the hydrogen electrode in these solutions to the cube of [H'] in aluminium chloride solutions. KAl(oa) = 1.06 x Mz zx 47.0. 19 20. Conclusions. Progressive Hydrolysis .-In solutions below 0.01 N the third stage of hydrolysis exists, AlCl + 3HOH = Al(OH) + 3€€Cl, Al"' + 30H' -+ Al(OH),.AlC1" + 20H' -+ AlCl(OH),, or the ionic reaction For the second stage having the ionic reaction the expression should be constant. Here l K w denotes the ionic product of water. Similarly for the first stage the expression cy1* Kn [H'] . [AIC;l,OHS should be constant. These relations cannot however be tested as the concentrations of AlCl(OH) and AlCl(OH) are not known with sufficient accuracy. Since the base AlC1,OH containing two chlorine atoms is prob EEYROVSK$ ELECTROAFFINITY OF ALUMINIUM. PART I. 21 ably weaker than the base AlCl(OH) having one more chlorine atom in place of hydroxyl the slight increase of hydrolysis in the most concentrated solutions (minimum in 0*5N-aluminium chloride solution; see Fig.2) might be interpreted as due t o first-stage hydrolysis. A similar minimum of hydrolysis in the most concentrated solu-tions was found by Kablukov and Sachanov (Zeitsch. physilal. Chem. 1909 69 419) in the hydrolysis of aluminium bromide a t 2 5 O and by Bruner (Zeitsch. physikal. Chem. 1900 32 133) in the hydrolysis of aluminium chloride a t 40°. The determination of hydrolysis by means of hydrogen electrode potentials has been made by Denham (T. 1908 93 41) who obtained for aluminium chloride solutions ranging from 0.19 to 0.024N values of the potential of the electrode about 20 millivolts lower than those observed by the author. He therefore found three times more hydrolysis.In his experiments the liquid potential was eliminated by means of a concentrated solution of ammonium nitrate the solutions being allowed twenty-four hours to come to equilibrium. The hydrolysis of aluminium salts seems to be influenced by the mode of dissolution. For example if the solution is raised to a temperature above 25O it does not necessarily return to the same condition a t 2 5 O its it was before (Jones Zoc. cit.). Moreover a slight excess of hydrochloric acid in the dry salt would cause too great an acidity and any adjustment of the equilibrium takes place very slowly. This difficulty in attaining equilibrium if once disturbed seems to be due to the presence of colloidal aluminium hydroxide which exhibits the phenomenon of ageing showing marked insolubility when not in the nascent state.The solutions must he therefore prepared and kept so far as possible at the same temperature. Kablukov and Sachanov's results (loc. cit.) for the hydrolysis (at 25O) of aluminium bromide calculated from E.M.F. measurements are very close to the values given in this paper. The Heat of Ionisation of ,4 Izcmim*um Hydroxide .-Kulgren (Zeitsch. physikal. Chem. 1913 85 466) measured very accurately the hydrolysis of aluminium chloride a t 8 5 O and looo. From his results and from the values given in Fig. 2 (curve h) the heat of ionisation of aluminium hydroxide can be obtained in the follow-ing way. The degree of hydrolysis of aluminium chloride a t the dilution v=512 is 4.7 per cent. a t 25O 34.09 per cent.a t 85O and 47.68 per cent. a t looo. Since a t this dilution the third stage of hydro-lysis exists the heat of ionisation of the reaction, Al"' + 30H'- Al(OH) solid 22 HEYROVSK~ ELECTROAFFINITY OF ALUMINIUM. PART I. can be calculated from the data given above by means of van't Hoff's isochore. Thus considering the equilibria a t two temperatures T and T', Further a t the same dilution u=512 the concentrations of the Al"' ions can be taken as equal to the non-hydrolysed portion in solution and since a t this great dilution some solid aluminium hydroxide will certainly have separated out we can write: where h denotes the fraction hydrolysed and iTAl(OH) and E'Al(oHl,, are the solubility products. Substituting in van't Hoffs formula, we get " Taking K at 1OO0=48x 10-14 a t 850=27.6 x 10-14 and a t 25O= 1 x as extrapolated from Noyes' numbers (Zeitsch.physilcal. Chem. 1910 73 1)) we obtain: Q between 25O and 100°=11970 cal., Q 7 25O 9 ) 85O= 12860 cal. Thus the heat of ionisation of one gram-molecule of solid aluminium hydroxide into the ions Al'" and OH' is about 12000 cal. When neutralised by strong acids one equivalent of aluminium hydroxide should evolve 13.700 calories less than the heat necessary to ionise the molecule that is, 13700 -4133 = 9567 cal. Thomsen found 9320 cal. which agrees with the calculated value, indicating a base of medium strength. The Diffusion Potential. Having found the ionic concentrations and the corresponding mobilities it seemed interesting to compare the potential differences observed on liquid boundaries between single aluminium chloride solutions with the values calculated from Henderson's formula (Zeitsch.physikal. Chem. 1908 63 325). The formula for the diffusion potential E is E = RT (u1-v,>-(u2-v2) ul'+v,' F ' ( Ul' + Vl') - ( U + V;) loge U T V T ' - - where V l = V G fV,G2+ . . . . - U,=u~C,+uBCa+ . . . . U1' = UICIZO1 + ZL2C2Z1l2 + 1-1 - . . . . V1' = Vu1ClWl + v2c2zu2 + . . . HEYROVSK~? ELECTROABPINITY OF ALUMINIUM. PART I. 23 c c denoting concentrations of cation and anion, u , equivalent mobilities of cation and anion, w,w , valencies of cation and anion respectively. I n the special case of aluminium chloride, Ul + Vl = K (specific conductivity) therefore Ul = K - 75 CX. Further neglecting the hydrolysis, V = V,' = ex = 75 .ex. u1- V'l =Kc- 150 C X = C ( X - 150~). 77 = c(yliwl + y2. 2M2 + y3 . 3M3) U,' = c(ylM1 + 29 . 2M2 + 3y3 . 3^3f3) Uz' - Ul = c(2y$f2 + 6y3M8) hence further Ui' + Vi' = ~ ( 2 ~ 2 M 2 + 6~3M3) + Ul+ v1 = c(& + 2y2M3 + 6y&f3)* Finally, TABLE 11. Preliminary Calcula tiolts. Concen-tration of AICI, in equiv-alent/ litre. A,!. 0.1227 85-7 0.0184 104.7 0.0092 110.3 0.00613 213.7 Ac + 2M2~3+ ~ M Y + 2. y3. ~ 1 . 6Mg3. 150~. 6M3yS. 0-730 0.1 0.2 48-4 -23.8 134.1 0.814 0.14 0.18 58-3 -17.4 163.0 0.838 0.16 0.17 63-4 -14.4 173.7 0.851 0.17 0.16 65.3 -14.0 179.0 b-Q,Z C(AC + c(&- 2M 2~ 2 + 1502). 6M3y3)--2.92 16-45 -0.38 2-99 -0-133 1.598 - 0.0868 1.097 a - a t b b - b Calculation of E = 0.059 - I log, volts.According to Henderson's paper the E.M.F. is here denoted as positive if the current passes from the first solution t o the second inside the cell. E.M.P. measured between calomel electrodes in AlCl solutions of concentration. single 0-1227 0.0184 0.019 0.1227 0.0092 0.040 0.1227 0.00613 0.046 0.0184 0.092 0.017 0*0184 0.0613 0.027 P.D. of & electrodes. E.2M.P. observed without elimin-ation of E diffusion P.D. observed. 0*0100 - 0.009 0-0290 - 0.01 1 0.0321 - 0-014 0.0153 - 0-002 0.019 - 0.008 E calcu-lated. - 0.0084 - 0.01 12 -0.0128 - 0.0022 - 0.003 24 HEYROVSK$ ELECTROAFFINITY OB ALUMINIUM. PART I. I n table 11 the potential differences calculated in this way are compared with those directly observed this being the first instance in which Henderson's forinula could be tested in the case of tervalent iona.I FIG. 2. The Actavzty of H ydrochlorac Aczd an Alumzlzzum C'hCorzcCe Solutions. The results of E.M.F. measurements are plotted in Fig. 2. The lines marked T K C l and rAlClI give the potentials of calomel elec-trodes in solutions of potassium chloride and aluminium chloride respectively showing that the activity of chlorine ions in aluminium chloride solutions is very near t o that which obtains in equivalent solutions of potassium chloride the dissociation into chloridions in the case of aluminium chloride being only about 20 per cent. less than in the case of potassium chloride HEYROVSK~ ELECTROAFFINITY OF ALUMINIUM.PART T. 25 The abscissz in Fig. 2 are in all cases logarithms of the con-The curve h = 0,. shows the change of hydrolysis with dilution. The curve 7rH represents the potential of the hydrogen electrode in aluminium chloride solutions referred to the normal calomel electrode as zero (the values to be taken as negative). The curve EAIC1 shows the variation of E.M.F. of the cell Hg I calomel AlCl solution I H, giving the activities of chlorine and hydrogen ions or the activity of hydrochloric acid according to the formula centration c expressed in gram-equivalents per litre. EAICI = RT log pE ' - = 0.2837 - 0.0591 loglo [H*) . [Cl'] [H'] . [Cl'] = 0.2837 - 0.1 182 10g,O [HCI]. Thus the curve EAIC13 shows the partial pressures of hydrochloric acid formed by the hydrolysis of aluminium chloride.If this curve is compared with the curve E,,,, expressing the partial pressure or activity of pure hydrochloric acid solutions as obtained from the results of Tolman and Ferguson (Eoc. cit.), corrected from 1 8 O to 25O i t is possible to find for every aluminium chloride solution the concentration of pure hydrochloric acid which would have the same activity of hydrogen chloride (exert the same partial pressure). Thus in 2.29 N-AlCl the HCl tension is that of 0.176 1-00 , , 0.0582 ,, N-HC'1. 99 0.368 , 9 7 , 0.0184 ,, 0.100 , 9 7 , 0*00617 ,, 0.0184 , 3 , 0*0017S )) the potential difference between calomel and hydrogen electrodes, that is the ordinate in each pair of solutions being the same. The values of E,, for dilute solutions have been obtained by extrapolating from the observed values and assuming that E, increases by 0.1182 volt for a decrease in concentration of 10 1.sponding with the theoretical increase of E.M.F. by Similarly the line EAICI was produced in the direction corre-RT log [H'] . [Cl'] = -log [Al"'Ja. c = E l o g c = $- .0.0591 volt P F €or tenfold dilution which a t the highest dilutions will be greater owing to the decrease of Al"' ions due to the precipitation as Al(OH),. As is seen in the figure these lines will meet a t a normality o about 0-000027 where practically total hydrolysis is reached so that in concentrations less than lO-5iV aluminium chloride behaves similarly to boron trichloride which is completely hydrolysed in solution; on the other hand aluminium hydroxide does not dissolve in 10 - "V-hydrochloric acid to form aluminium chloride.The value of rH a t great dilutions has been assumed t o be pro-portional to log[H']. From this the value of rH in a neutral solution is 0.70 volt. The line EKC, representing the activity of hydrochloric acid in solutions of an ideal non-hydrolysable chloride of a strong base, has been drawn in which rH is taken as equal to 0.700 volt. Similar E.M.F. curves for chlorides must all lie between the two extremes namely E,, and E,, lines the slope becoming steeper as the alkalinity of the metal decreases. Thus a chloride of a strong base like lanthanum trichloride would give a curve very similar to ITKCI whereas boron chloride would give nearly that of E,,,. This would be a precise and distinct way of expressing hydrolysis. Summary. (I) From conductivity data and E.M.F. measuremenh of aluminium chloride concentration cells the amount of ionisation and hydrolysis was determined and the gradual ionisation of cations calculated. (2) The ionisation of aluminium chloride into chloridions is about 20 per cent. less than the ionisation of potassium chloride of equivalent concentration. (3) The basic solubility product of aluminium hydroxide is (4) The heat of ionisation of aluminium hydroxide has been (5) The mobility of the ion Al"'=3 x 49.2 that of the ion (6) Henderson's formula for the diffusion potential between [Al"'] . [OH']3= 1.06 x 1 0 - 3 3 . calculated. AlCl" = 2 x 47. solutions of aluminium chloride has been found to hold good. CHEMICAL DEPARTMENT OF UNIVERSITY COLLEGE LONDOE. CHEMICAL INSTITUTE OF THE CZECH UNIVERSITY PRAGUE. [Received October 20th 1919.

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J O U R N A L A. J. ALLMAND M.C. D.Sc. 81a JAMES J. DOBBIE M.A. D.Sc., M. 0. FORBTER D.Sc. Ph.D. F.R.S. T. A. HENRY D.Sc. J T. HEWITT M.A. D.Sc. Ph.D., A. W. CROISLEY C.M.G. C.B.E., D. Sc. F. R. S. F. R.S. F.R.S. OF C. A. KEANE D.Sc. Ph.D. T. M. LOWRY C.B.E. D.Sc. F.R.S. J. I. 0. MASSON M.B.E. D.Sc. G. T. MORGAN O.B.E. D.8c., J. C. PHILIP O.B.E. D.Sc. Ph.D. A.SCOTT M.A. D.Sc. F.R.S. H. R. LE SUEUR D.SC. F.R.S. THE CHEMICAL SOCIETY, TRANSACTIONS. Lbitm : J. 0. UAIN D.Sc. Snb-CMh : A. J. GREENAWAY~ 1920. Vol. CXVII. Part II. pp. 819-end. LONDON : GURNEY & JACK.SON 33 PATERNOSTER ROW E.C.4. 1920 PRINTED IN GREAT BRITAIN BY RICHARD CLAY 64 SONS LIYITED, PARIS GARDEN STAbtFORD ST. BE. 1, AND PUNQAY I)UyyOLK

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年代:1920

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HEYROVSK~ ELECTROAFFINITY OF ALUMINIUM. PART n. 27 1V.-The Electroafinity of Aluminium. Part 11. The Aluminium Electi*ode. By JAROS LAV HEYROVSK G. Passiu e A luminizcm . Potentials.-The position of aluminium in the electro-potential series has long remained uncertain. Thus Streinz (Ber. lVien. ilkad. 1878 77 410)) from measurements in aluminium nitrate solutions placed aluminium as follows : . . . . - A1 Mg Zn Cd Sn Pb Fe . . . . +, and from measurements in aluminium chloride solutions thus : - . . . . Mg Zn Al Cd . . . . +. Wright and Thompson (Phil. Mag. 1885 [v] 19 102 197) found aluminium to be more positive than zinc in solutions of chlorides by 0.280 volt of bromides by 0.295 volt and of sulphates by 0.537 volt although from thermo-chemical determinations they expected a potential one volt? more negative than for zinc.Neumann (Zeitsch. physikal. Chem. 1894 14 193) using amalgamated aluminium placed it' as follows : . . . Mg Al Mn Zn . . . Burgess and Hambuechen (Electrochem. Ind. 1903 1 165) found that the potential of aluminium wires varied from -0.3 to -1-3 volt (referred to the normal hydrogen electrode). Van Deventer (Chem. T'lieekblad 1907 4 625 771) found that amalgamated aluminium had a potential similar to magnesium, whilst the inactive metal was more noble than zinc. Obviously in all cases where the metal is not amalgamated, aluminium remains in a passive condition the passivity being caused by a skin of oxide or hydroxide as is evident on dissolving aluminium in dilute alkalis or during amalgamation when the coherent skin peels off.The potential of metallic aluminium like that of any passive electrode is not influenced by the presence of aluminium ions in solution. The metal behaves rather as a gas electrode being sensitive t o oxidising and reducing agents besides being influenced by anions (compare Jory and Barnes Trans. Anzer. Electrochem. SOC. 1903 3 95). Great sensitivity to shocks was also observed. The following table of experimental results shows the passivity of aluminium wire 28 HEYROVSK~: Cell (at room temperature), first electrode is +. calomel H g I N-KCIsoln. j *l calomel ‘-Ig ~ N/lO-KCl s ~ l n . ! ~ ~ ’ ELECTROAFFINITY OF ALUMINIUM. PART 11. 0 bserved E.M.F. Behaviour. in volts. 0.77-1.67 Showing sudden changes and great fluc-twations of E.M.P.When not moved 0.7 6-0.80 Immedat-ly after the aluminium surface has been rubbed on glass fragments. Allowed to remain. < 1.0 Again rubbed. 1.48 1.40-1.47 Current of oxygen passed round the 0.6-0.7 electrode. (least observed E.M.F.) Current of hydrogen passed. 1-38 The potential is most negative in solutions of chlorides; it is less negative in bromides iodides sulphates and most passive in nitrate solutions. Evidently solutions of compounds of a more oxidising character passivify aluminium more intensively. This is in accord-ance with the known fact (compare Miiller Zeitsch. physill-d. Chem. 1909 69 481) that the passivifying influence of an anion is inversely proportional to the solubility of the product formed a t the electrode (that is the oxide).Dissolution of 2lXetaZZic A lzcminium .-The combined action of the active cation H’ and the anions Cl’ Br’ and I’ activates aluminium so that it decomposes water evolving hydrogen even in the dilute acids. Centnerszwer and Sachs (Zeitsch. physilcd. Chem. 1914 87 692) found that the rate of evolution of hydrogen in N-hydrochloric acid was 0.066 C.C. per sq. cni. per minute in N-hydrobromic acid 0-002 c.c. and in hydriodic acid still less. The dissolution in N-sulphuric acid was much slower whereas in nitric acid no hydrogen was evolved. The following experiments were made at the ordinary temperature : Evolution Acid used. of hydrogen. Notes Snlphuric acid N/10. None. But solutions in contact with metal for some days were found to contain aluminium salt.Slow. - 3 N . , concentrated. Slow. Yellowish or orange coating of sulphur Nitric acid diluts or None. Solutions were found to contain alu-concentzrated. minium salt. If some chloride is Hydrochloric acid di- Strong. I f potassium chlorate is added evolu-Sulphurous acid. Moderate. Odour of hydrogen sulphide. deposits on metal. added bubbles are evolved at once. lute or concentrated. tion increases HEYROVSK$ ELECTROAFFINITY ox ALUMINIUM. PART 11. 29 Evolution Acid used. of hydrogen. Nohes. Organic acids. None. Insoluble. Potassium iodide and Slow. -iodine solution. Potassium sodium or Strong. Concentrated ammonia and potassium barium hydroxides carbonate solutions also dissolve the dilute or concen- metal.trated. The dissolution in pure Concentrated sulphuric acid is interest-ing. If we suppose that electrochemical processes cause corrosion, then the precipitation of sulphur on aluminium must be regarded as cathodic deposition the few cations S""" which might exist in minute quantities in concentrated sulphuric acid being thrown down as a more noble element with less solution tension than aluminium. Electro-deposition of Metals by *4 luminium.-Similarly the deposition of any other more noble metal on aluminium is influenced by anions present in solution as they determine the potential of the metallic aluminium. Solution into which Deposition of I n this connexion the following results were obtained: Evolution aluminium is dipped. of metal. hydrogen.Notes. Gold chloride dilute. Gold deposits at once. Strong. Mercuric chloride Instantly amalgamated. Strong. dilute. Mercurous chloride. Slow amalgamation. Slow. Solution of mercuric No action. oxide in nitric acid. ' -Silver nitrate dilute Fine crystals of silver. Cupric chloride cu- Copper deposits readily. None. Slow. or concentrated. pric bromide cupric chloride and potass-ium iodide. (jopper sulphate. Very slow deposition oi None. copper. Fehling's solution. Y 9 s Slow. Cupric nitrate. Scarcely any action. -Ammoniacal copper No action. -Ferrous sulphate. No action. -Zinc sulphate. -solution. Ferric chloride. Dark powder deposits. Slow. Zinc chloride. No action. -Alkaline solution of Grey crystalline powder. Slow. 9 , zincate.Solution turns violet. Mercurous chloride must be in contact with metal. If trace of chloride is added amalga-mation occurs. Solutions decolorise 30 HEYROVSKg ELECTROAFFINITY OF ALUMINIUM. PART 11. Active Aluminium. Aluminium when active that is when dipping into a solutioii of hydrochloric acid or alkali hydroxide decomposes water vigor -ously and cannot be used for precise E.M.P. measurements. Neumann (Zoc. cit.) therefore used amalgamated aluminium, which causes less rapid evolution of hydrogen. He obtained as the mean value of rather variable potentials in N-aluminium sulphate solution - 1.317 volt8 in N-aluminium chloride solution - 1.292 volts in N-aluminium nitrate solution - 1.052 volts, referred to the normal hydrogen electrode as zero.Even such an electrode is far from being a reversible one since the hydrogen ions discharging on the electrode make the potential more positive just as silver ions do in silver concentration cells. I f the evolution of hydrogen could be prevented that is if the potentJal of hydrogen could be lowered below that of aluminium, a reversible aluminium electrode would be obtained. The potential of - amalgamated aluminium wires in 0-0213A'-aluminium chloride solution saturated with hydrogen under atmo-spheric pressure was indeed found to be less variable and more negative namely - 1*330+0.003 volts but slow evolution of hydrogen could not be prevented. The high overvoltage of hydrogen on a mercury surface makes it possible for a dilute amalgam of a very negative metal to behave as a reversible electrode because the evolution of hydrogen is almost entirely prevented.Lewis ( J . Amer. C'hem. Joc. 1910 32 1458; 1912 34 119; 1913 35 340; 1915 37 1893) has been able to determine the electrolytic potentials of alkali metals using dilute amalgams and the same method has been adopted here. for aluminium. Preparation of A lunainium A ma1gam.-About 0.4 gram of aluminium (99.6 per cent.) was dissolved in 200 grams of pure dry mercury by boiling for two to three hours in an atmosphere of dry carbon dioxide. On cooling some solid amalgam separated o u t on the surface showing that this very dilute (about 0.1 per cent.) amalgam is saturated. This anialgain is extremely easily decom-posed in moist air instantly losing its lustre and becoming covered by hydroxide this being no doubt due to the great affinity of aluminium for oxygen and its small affinity for mercury.Whether this saturated amalgam shows any difference of poten-tial from pure active aluminium or not could not be ascertained, since aluminium was found to be passive in dry acetone ether or piperidine. However since the liquid amalgam is in contact with solid amalgam their solution tensions must be identical and a HEYROVSKg ELECTROAFFINITY OF ALUMINIUM. PART II. 31 the aluminium seems to be very loosely bound to mercury the heat of oxidation of the solid amalgam has been found to be the same as the heat of oxidation of aluminium (Baille and FQry Ann. Ghim. Phys. 1889 [vi] 17 246). The electrolytic potential of the liquid amalgam must be very near to that of ideal active aluminium.Measurement of E.M.F.-The glass apparatus in which the amalgam had been prepared was inverted and the amalgam allowed to pass through a side tap by which the flow could be regulated into a sealed-on capillary tube (of 1 mm. bore) with a platinum contact. The lower end of the capillary tube was bent up and opened out so as t o provide a larger surface of amalgam. The electrode dipped into a solution of aluminium chloride which was stirred by means of a stream of hydrogen bubbles. The space above the solution was thus kept filled with hydrogen under atmo-spheric pressure. The second electrode was a hydrogen electrode consisting of platinum coated on glass as used by Loomis and Acree (Smer.Chem. J. 1911 46 585 621 638); there was also a calomel electrode attached to the vessel filled with the same aluminium chloride solution to check the hydrogen electrode from time to time. A t the beginning of each experiment hydrogen was passed through the cell until the potential difference between the calomel and hydrogen electrode became constant. Then the tap on the capillary tube was opened and the amalgam allowed to drop out slowly. It was found better to allow the amalgam to flow slowly, as on fresh surfaces after a few seconds bubbles of hydrogen appeared. Since however during readings the potential increased by several millivolts this being no doubt due to electrical adsorp-tion of ions on drops of mercury the solution round the electrode was stirred by bubbling hydrogen through it and simultaneously the aluminium chloride solution through which hydrogen was first passed was allowed to flow into the space round the electrode.A second series of measurements was made with new amalgams and capillary tubes and the results obtained did n o t differ by more than 10 millivolts from the first series even in the most dilute solutions whilst in the stronger solutions the agreement was within 3 millivolts. I n this way the following readings were obtained (using accumulator Weston cell Lippmann electrometer and potentio-meter giving readings to 0.1 millivolt): The whole apparatus was kept in a thermostat a t 25.0° 32 HEYROVSE< ELECTROAFFINITY OF ALUMINIUM. PART 11. Concentration of Mean E.M.P. of gram-equivalents AlCI Al-aluminium chlorides in per litre.the cell : + - ~ 2 1 solution 1 amdgam. (2.88 1.128 volt 0.1845 1-164 0-0675 1.160 0 0337 1-157 0.02 13 1.145 0.0107 1-161 (0.006Ti5 1.135 (0.00213 1.136 AM referred to the normal hydrogen electrode. - 1.284 volt) - 1.382 - 1-381 - 1-397 - 1.370 - 1.383 - 1.381) - 1.377) The determinations of single hydrogen electrode potentials are described in the preceding paper (p. 15) from which the potentials of aluminium amalgam electrodes rA (third column) could be calculated. The solutions were prepared from aluminium chloride purified by precipitation with hydrogen chloride and to each solution excess of freshly precipitated aluminium hydroxide was added. In such solutions the solubility product [Al"'] .[OH133 should be constant and equal to k . [Al(OH),]. Then the electrolytic potential of aluminium becomes where K is a constant. Such an electrode therefore behaves as a hydrogen electrode or an oxygen electrode of the type Hg [ HgO and consequently its potential qAl should always differ from the platinised electrode by a constant. The difference between the two electrodes (column 2) is very nearly constant except in the case of the first solution which was very viscous and opaque. I n the two most dilute solutions the J?.M.F.'s were rather variable sometimes approaching 1- 16 volts. The value of zA1 on the whole falls with the increase of acidity and concentration of aluminium chloride. In order t o determine how the potential of the aluminium electrode is influenced by different solutions a simpler form of apparatus was used having two capillary amalgam electrodes dipping into solutions saturated with hydrogen and covered by a layer of liquid paraffin.In this case the amalgam was not allowed to drop continuously but the surface was renewed every few minutes. The values obtained in %his way (at 2 5 O ) are given in table I. Single potentials are referred to the normal hydrogen electrode Solution used in the Al-electrode. NIlO-HCl 2.90 N-AICl, 0.368 ,, 0-0675 ,, 0.0409 ,, 0.0184 ,, 0.0046 ,, 0.00306 ,, 0.0028 ,, 0.30 N-Al,(SO,), 0-030 ,, NIlO-KCI N-KCl N/lOO-KOH+Al( OH), N/10- 9 9 ) NI10-KOH Second electrode. NIlO-KCl calomel. N-KCl calomel.Calomel of the same solu-tion. Y, 9 9 99 ?? N-KCl calo$el. 9 , Y, 9 , Y Y Hg+HgO of the same solution. 7 9 N-KOH saturated with $ 9 -4I(OH)3 TABLE I. Observed E.M.F. in volts. 1.5790 1.5A1-55 1.674 1.699 1.702 1-724 1.755 1.770 1.630 1.700 1.742 1.785 1.750 1.910 1.774 1.752 1.713 Potential of Al- electrode, AAI. - 1,209 1 2 6- 1.27 1.374 1.359 1.342 1.343 1.349 1.345 1.347 1.417 1.459 1.502 1.467 1.622 1.576 1.613 1.596 rH a dipping th 34 HEYROVSKP ELECTROAFFINITY OF ALUMINIUM. PART 11. Some determinations of single electrode potentials rA1 and rH, a.re calculated from the results described in the preceding paper; the electrode potentials in potassium hydroxide solutions were obtained by elimination of the diffusion potential with concentrated potassium chloride solutions.With fresh surfacw the E.M.F. rose a few millivolts to a maximum and after three minutes began to fall slowly. If the solution round the electrode was stirred or the electrode shaken, the E.M.F. fell about 20 millivolts but reverted to the original value on keeping. Oxidising agents such as dilute solutions of ferric chloride or hydrogen peroxide or even a current of air, caused a considerable decrease of negative potential amounting to several decivolts ; reducing agents had no influence. The more acidio the solution the more stable was the E.M.F. and fewer bubbles of hydrogen appeared on the surface of the amalgam. In N/10-hydrochloric acid no bubbles were formed and the E.M.F.was constant for t7en minutes a t 1.5788 volts,. whereas in alkaline solutions there was a visible elvolution of minute bubbles. Discussion of Results. From the most trustworthy measurements of rA1 in 0.1845N-AlC1 = - 1.370 volts where [A41*'*] = 0*0130* 0.0675 , = - 1.382 , , =0.0080 0.0337 , = - 1.383 , , =0*0044 the theoretical value for t.he electrolytic potential of aluminium in a normal solution of aluminium ions E.P. has been calculated by the formula E.P. = rA - ~ ~ l o g J A l " ' ] = rA - 0.0591 log, [ Al' 'I. 3 F 3 The values -1.333 -1.341 -1.336 calculated in this way give E.P. = - 1.337 volts as the most probable value. The approximate value of the electrode potential can be obtained from the heat of the electro-chemical reaction if we neglect the term T .__ in the equation T = Q + T. - and assume that the heat equivalent & of the reaction is equal t o the total change of energy. d?r drr d I' d T The heat of the reaction +A1 + HCl (in 200 as.) + iA1C1 + iH2 * See Part I HEYROVSKP ELECTROAJYFINITY OF ALUMINIUM. PART 11. 35 is 41.033 calories (Thomsen). of heats of ionisation of the processes: It can be regarded its the difference $A1 -f &Al**' +@ H + H + +(-) --giving +Al+H' -f QAl++++H, from which the calculated potential of the process A1 + Al"' t 3 0 is 1.76 volts whereas the potential corresponding with 31.000 calories of the reaction &A1 + H,O + &Al(OH) + &HZ leads to 1-34 volts. This would apply to the electrochemical process A1 + 30H' -+ Al(OH) + 3 0 .The coinoidence of the latter value with the observed one was pointed out by Kistiakovsky (Zeitsch. physikal. Chem. 1910 70, 260) who suggested similar electrode reactions for magnesium, iron and chromium. The reason why only the process A1 + 30H' -+ Al(OH),+ 3@ is the source of electrical energy must be sought in the extremely small solubility product of aluminium hydroxide (= 10-33; see Part I) effecting considerable hydrolysis. Owing to this the layer of solution close to the surface of the amalgam is saturated with aluminium hydroxide so that the potential is determined by hydroxyl ion concentration directly by aluminium ion concentra-tion only through the solubility product equilibrium. This is evident from table I where with decreasing acidity rA1 increases.Owing however to increasing oxidation of the amalgam in less acidic solutions the values are shifted towards more positive potentials so that in these solutions the potential density from the hydrogen electrode (column 4 table I) decreases instead of being constant. The reason why even in acidic solutions (like 0-1N-hydrochloric acid) the ordinary ionisation potential of A l e Al'" + 3 0 is not attained but the value remains roughly that of A1 + 30H' -+ Al(0H) + 3 0 , must be sought in the extremely slight dissociation of aluminium hydroxide which does not react sufficiently quickly with the acid to form aluminium ions and remains far behind the reaction c 36 MASON AND WHEELER THE PROPAGATION OF determining the electrode pot eyatial. tion might be a molecular one not ionic thus: Al(OH) + 3HCl+ AlCl,aq., Moreover the second reac-and need not take place at the electrode. Summary. (1) Various potentials of passive aluminium have been measured, and the influence of the anion on potential dissolution and deposition of metals is discussed. (2) The potential of active aluminium in the form of saturated liquid amalgam has been measured in different solutions. (3) The theoretical value of E.P.= -1.337 volts a t 2 5 O the normal hydrogen electrode being taken as zero. The correspond-ing electrochemical reaction being A1 + 30H' -+ Al(OH) + 3 0 . I n conclusion I desire to express my thanks to Prof. F. G. Donnan a t whose suggestion this work was undertaken for his kind interest and advice. 7 also wish to express my indebtedness to Dr. R. E. Slade for his constant help throughout this investigation. CHEMICAL DEPARTMENT, UNIVERSITY COLLEGE LONDON. [Received October 20th 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700027

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

36 MASON AND WHEELER THE PROPAGATION OF V.-The Propagation of Flame in Mixtures of Methane and Air. Part I. Horizontal Yropaga tion. By WALTER MASON and RICHARD VERNON WHEELER. IN previous communications to this Society a study of the initial “ uniform movement” of flame in gaseous mixtures has been pre-sented (T. 1917 111 267 1044; 1919 115 578). The majority of the experiments of which an account has been given have been with methane as the combustible gas. The general conclusions drawn as to the character and ratisonale of the uniform movement are however applicable to all inflammable mixtures. The uniform movement is one phase in the propagation of flame, and is of comparatively short duration. The speeds attained by th FLAME IN MIXTURES OF METHANE AND AIR. PART I.37 flames during its regime are comparatively slow; very slow com-pared with that of the detonation-wave but slow also compared with the speeds during other phases in the propagation of flame in mixtures wherein the detonation-wave normally does not develop. The value of determinations of the speeds of flames during the uniform movement lies in the measure thereby afforded of the general behaviour of a given iiiflanimable mixture or range of mix-tures immediately after ignition the measurements when made under standard conditions being physical constants. Knowledge is however odten necessary of the maximum speed attainable a t any time during the course of the propagation of flame in mixtures of a given comb’ustible gas with air or oxygen. Such knowledge is of prime importance for example in respect of mixtures of methane and air in connexion with the safe wolrking of coal mines.I n the present paper a description is given of the phases other than the uniform movement during the horizontal propagation of flame in mixtures of methane and air. The several series of experiments were carried out in tubes of different dimensions and materials. It is important when compar-ing one series of experiments with another that due regard should be paid to the details given respecting the tubes employed. I n the majority of the experiments measurements of speeds were made by tho “ screen-wire ” method of which full details have been given in earlier papers (T. 1914 105 2610; 1917 111 1053). Supple-mentary information was obtained by photographic analysis of the flames.I n order to obtain the1 photographs the flames were caused to travel along a tube of brass 5 cm. in diameter furnished with a window of quartz which was focussed on a rapidly revolving film by means of a quartz lens. The use of quartz enabled the light falling on the film to be sufficiently actinic to record the movements of the flames with con~iderab~le detail. (I) Ignition at the Open End of a Tube Closed at the Other End. The initial phase of propagation of flame when the mixture is contained in a horizontal tube closed a t one end and open a t the other and ignition is a t the open end constitutes the “uniform movement .” The linear duration of the uniform movement is controlled by the s p e d of the flame (and thus by the composition of the inflam-mable mixture); by the length diameter and unifmormity of bore of the tube; in short by such factors as influenoe the establishment of resonance in the colrimn of g a w in the tube.Eventually as a dirmt outcome of the establishment of resonance the flame-froa 38 MASON AND WHEELER THE PROPAQATION OF acquires a periodic undulatory motion (sele T. 1919 116 584) leading sooner or later to violent vibrations which vary considerably in amplitude but remain periodic. This phase in the propagation of flame was discovered by Schloesing and de MondBsir and was termed ‘( le mouvement vibra-toire” by Mallard and Lei Chatelier (Ann. des Mines 1883 [viii], 4 331). Although accurate record can be obtained of the develop-ment of the ‘( vibratory movement ” under chosen conditions the measuremonts-of the mean speed of the flame for example-are not of much theoretical significance or practical value for the speed of the flame during any one vibration and the amplitude of the vibrations is very susceptible of changes designed or inadvertent, in the experimental conditions.Sol far as mixtures of methane and air are concerned it is perhaps sufficient to record a few of the data obtained as indicative of the general character of this phase in the propagation of flame for com-parison with the uniform movement which precedes it. Thus with mixtures containing betwelen 10 and 10.5 per cent. of methane and with a tube of brass 240 cm. long and 5 cm. in diameter the signi-ficant measurements obtained by photographic means are as f OllO~W : Speed of ff ame during unif o m movement Linear duration of uniform movement ...... 80 om. . . . 90 cm. per second. Faint undulations of the flame-front. appear after the flame has travelled 32 cm. The mean speed of the flame is not affected by these undulations; their amplitude is small,. and their period is that of the resonating column of gases in the tube. The amplitude of the undulations increases gradually from 1.7 cm. over the distance 32-50 cm. to1 1.9 cm. over the distance 50-60 cm. and 2.2 cm. over the distance 60-80 cni. It then begins t o increase rapidly, becoming 3.6 over the distance 80-90 cm. During this period o€ rapid increase in amplitude of the undulations the mean speed of the flame falls to 64 cm.per second. Eventually the “vibratory movement,” which owes its origin to1 an undulation of abnormal amplitude is established. During the vibratory movement the oscillations of the flame are of wide amplitude-25 cm. or more-and the mean speed of trans-lation of flame is considerably enhanoed. It will be seen on exam-ination of Plate I Fig. 1 that the change of speed from that of the uniform movement (90 cm. per sec.) t o that of the vibratory move-ment (278 cm. per sec.) is fairly abrupt and that the latter speed is maintained a t a constant mean value over a considerable dis-tance. Finally as the flame approaches the closed end of the tube FLAME IN MIXTURES OF METHANE A N D AIR. PART I. 39 its mean speed decreasw although it still continues to vibrate to the end.In the table that follows data are given respecting successive portions of the vibratory movement each portion being specified by the distance along the tube over which the flame travelled. Vibratory Movement of Flame. 10-10.5 per cent. in air.) (Tube of brass 240 cm. long and 5 cm. in diameter. Methane Distance along tube. 0-80 cm. 80-90 90-107 107-170 170-200 200-220 220-240 Mean speed of flame. Cm. per sec. 64 278 62 38 --Maximum speed during forward motion of flame. Cm. per see. Unif o m movement 292 Gradual change 2,430 Gradual change 416 -Amplitude of vi br ati om. Cm. 3.6 26.0 1.4 ----Frequency of vibrations. Mean values. It may be noted that as indicated by the frequency of the vibra-tions the resonating oolumn of gases is that lying between the closd 0nd of the tube and the flame-front at any given moment.Thus the calculated mean value for the frequency of vibration of a column of gases in an unflanged tube of brass 5 cm. in diameter is 48 if the tube is 130-140 cm. long and 74.5 if it is 50-93 cm. long. These measurements bear reference only to the particular condi-tions of experiment specified but they could be reproduced with an exactness which must be considered remarkable when the compli-cated character of the1 phenomena is borne in mind. In this respect better fortune has attended the experiments than that which befel Mallard and Le Chatelier who have stated “ En rep6tant plusieurs fois la meme experience dans dehj conditions identiques B elles-mGmes, le mouvernent vibratoire ne se reproduit jamais deux fois de la m@me f a p n ” (Zoc.c i t . p. 333). No doubt the rapid speed of flame i n the mixture (CS + 6NO) employed by Mallard and Le Chatelier for their experiments would tend to emphasise irregularities in the results. It has already been stated that the vibratory movement is the direct result of’ the resonance of the oolumn of gases in the tube. It was shown in connexion with experiments on the propagation of flame in mixtures of acetylene and air that resonance by whatever means induced can be made manifest by the undulatory motion of flame as it travels along tubes the1 periods of the undulations agree-ing closely with the periods calculated for organ-pipes of the dimen 40 MASON AND WHEELER THE PROPAGATION OF sions of the t u b employed.As the resonance becomes stronger, the amplitude of the undulations of the flame front perform increases since the flame acquires its motiojn from the vibrating column of gases. There is thus produced an agitation of the gaseous mixture which eventually becomes of sufficient importance to affect appreciably the speed of a flame travelling through it. (In this connexion see T. 1919 115 81.) The vibratory movement is indeed an excellent example of the effect of agitation or turbulence in accelerating the translation s f flame through a gaseous mixture. The effect is a mechanical one. During each forward impulse the flame is drawn rapidly through previously unburnt mixture by reason of the motioa acquired by the resonating column of gases.I n a certain degree also the forward motion of the flame is assisted by the expansion in volume of the burning gases especially when the flame is a t some distance from the open end of the tube so that escape of the expanded gases there is retarded. The latter effect is more pronounced when the mixture is ignited a t the clomd end of a tube open a t the other end conditions which will be considered in the succeeding section of this paper. (11) Ignition at the Closed End of a Tube Open at the Other End. The two phases in the prolpagation of flame the '' uniform move-ment " and the " vibratory movement," are characteristic of what occurs with .mixtures of a oombustible gas and air when ignition is at the open end of a tube closed a t the other end.Under such conditions with some combustible gases (for example hydrogen) when mixed with air and with all when mixed with pure oxygen, the vibratory movement is succeeded by the detonation-wave, provided that the combustible gas and oxygen are in suitable proportions. With no mixture of methane and air (at atmospheric temperature and pressure) is the detonation-wave thus developed but the vibra-t o y m'ovement continues until the flame is extinguished either on reaching the closed end of the tube or occasionally during an abnormally extensive backward movejment before the end is xeached. When ignition of a mixture of methane and air is a t the closed end of a tube open a t the other no uniform movement takw place, but the speed of the flame increases rapidly as it travels towards the open end.For comparison with the uniform and vibratory movements, experiments were made with a sesies of mixtures in a horizontal tube of glass 5 cm. in diameter and 600 cm. long. Fine screen FLAME IN MIXTURES OF METHANE A?XD AIR. PART I. 41 wires of copper were stretched across the tube a t half-metre dis-t a n m and the times taken for the flames to travel between these screen-wires me'asured by the method described in previous com-munications. The mixtures were ignited a t a spark-gap 3 cm. from the closed end. The speed of the flame in some of the mixtures reached 29 m. per second over the last half-metre length of the tube and so far as could be judged was nearly uniform!y accelerated from the begin-ning.It seemed possible therefore that with a tube of greater length and larger diameter a permanent maximum velocity of flame, such as is characteristic of the detonation-wave might eventually be attained. A steel tube 30.5 cm. in diameter and 90 m. long was used to test this suppition. It was found that flame did not continue t o propagate in any mixture beyond a distance of 15 m. from the closed end a t which ignition was effected. Violent vibrations were developed after the flame had travelled 10 m. in the course of which the flame was extinguished. The same result was obtained when the mixtures were ignited a few cm. (ten t o twenty) from, instead of at the closed end a condition which would have the e'ffect of imparting an impetus to the flame a t the beginning, thereby hastening the development of the detonation-wave (com-pare Dixon Ph& Trans.1903 A. 200 345). The extinction of the flame after travelling such a short distance in a long tube under the conditions of these experiments is no doubt caused by the products of combustion when cooling tending to produce a partial vacuum behind the flame (the end of the tube from which the flame started being sealed) which is therefore dragged back over part of the path it has already travelled. This may occur several times the flame alternately leaping forward and being drawn back but eventually a sufficient proportion of the burnt mingles with the unburnt gases t o prevent further propaga-tion of flame.(111) Ignition at One End of a Tube open at Both Ends. I f the reason assigned f'or the extinction of the flame when travel-ling from the closed to the open end of a long tube is correct-a reason intended to apply only to such comparatively slowly-moving fla.mes as are obtained with mixtures of methane and air *-extinc-* With mixtures of coal-gas and air for example in which the flames are initially more rapid than with methane and air the vibratory movement continues (in a steel tube 30.5 cm. in diameter) until the detonation-wave is developed. The speed of the wave in a mixture containing 17 per cent. of coal-gaa is 1760 m. per second. 0 42 MASON AND WHEELER THE PROPAOATION OF tion should not occur when both ends are open (so that the cooling of the products of combustion cannot create a partial vacuum behind the flame) and the speed a t which the flame travels should be rapid.Several series of experiments were made to test this point it being important to determine the conditions under which the most rapidly moving flames are obtained in mixtures of methane and air, and the order of magnitude of the speeds. FIG. 1. Time seconds. me first series of experiments was in a tube of glass 5 cm. in diameter and 500 cm. long for comparison with the series carried out in the same tube in which ignition was a t a clmed end. The results are shown graphically in Fig. 1 in which distance along the tube is plotted against time zero time being the moment of fusion of the first screen-wire which was 10 cm. from the point of ignition.Wit,h all but the lower-limit mixture (5.40 per cent. methane), in which the speed of flame is uniform there is a gradual and s FLAME MlXTUBES OF METHANE AND AIR. PART I. 43 far as the records can indicate regular acceleration of speed as the flame travels from end to end of the tube. In no instance did extinction of the flame occur although in most of the experiments slight vibrations were noticed a t different stages in the develop-ment of the propagation the incidence of these vibrations being earlier the more rapid was the flame. There was also with the mixtures richer in methanel a noticeable check in the progress of €he flame as it approached a particular point succeeded by a spurt forward after that point had been passed. This effect seemed trace-able to a slight ridge around one of the small holes with which the tube had been pierced (by means of a blow-pipe flame) to receive the screen-wires used to record the time of passage of the flame.This ridge projected less than 1.5 mm. within the tube; the fact that it could markedly affect the progress of a flame in a tube 50 mm. in diameter is a striking example of the sensitiveness of flames to turbulence in the mixture even such slight turbulence as the small projecting ridge would cause. This subject will be dealt with in a subsequent. communication. Another series of experiments covered the whole range of inflam-mable mixtures of methane and air and was made in a glass tube 9 cm. in diameter and 620 cm. long. This series is of value for comparison of the mean speeds of the flame over measured distances with the speeds of the uniform movement in a tube of the same diameter.Such a comparison is made diagrammatically in Fig. 2, which records speed-percentage curves ( A ) for the distance (measured from the point of ignition) 50-100 cm. and ( B ) for the distance 407-467 cm. in the tube open a t both ends the speeds being the mean speeds of the flames over those distances; and (C) for the1 uniform movement. In addition a curve (D) is given showing the mean speed of flame over ths distance 20-120 cm. in a tube 5 cm. in diameter closed a t one end and open a t the other, ignition being a t the closed end. The mean speed over the distance 407-467 is wen to be greatest in the mixture containing 10 per cent.of methane and to be about four times the speed of the uniform movement in that mixture in a tube of the same diameter. The speed of the flame in all mix-tures (except the limit mixtures) was found as with the tube of 5 cm. in diameter to increase continuously over the whole distance travelled and as when ignition was a t the closed end of a similar tube it seemed possible that the detonation-wave might be developed if the flame could travel far enough. I f not it was necessary to know what change in the character of the propagation would interpose to prevent it. The steel tube 30.5 cm. in diameter was brought into requisition C" 44 MASON 'AND WHEELER THE PROPAGATION OF to test this. The length of the tube in the first instance was 15-25 m.and records were obtained of the times taken for the flame to travel measured distances from the point of ignition in different mixtures. As usual the fastest speed of flame was obtained with mixtures containing between 9.5 and 10.6 per cent. FIG. 2. 1800 1600 1400 2 1200 0 % 3 CJ F4 1000 f ii 800 ps % ' 600 & 400 200 4 6 8 1 I I 1 12 14 1 Methane per cent. of methane but no speed approaching that of the detonation-wave was recorded the maximum being 917 cm. per second attained after travelling 14 m. in a mixture containing 10.25 per cent. of methane. It appeared from the records that the flame which could not b directly oberved had acquired a vibratory character after travel-ling half the length of the tube. No indication of this was gven by the sound of the flames as they travelled and the vibrations were presumably of small amplitude.Vibratory propagation in the steel tube such as was obtained when osne end of the tube was closed had hitherto been accompanied by a staccato note but the flames now produced seemed to the ear to travel unhaltingly from one end of the tube to the other issuing into the air with a sharp report. The length of the tube was therefore increased ta 90 m. in the expectation that if the flame had indeed become vibratory in character after travelling 6 or 7 m. a greatly increased distance of travel would produce readily recognisable vibrations of large amplitude. Such was in fact the result; the propagation ulti-mately became strongly vibratory but the early stages of the propagation were profoundly modified by the increased length given to the tube.Instead of increasing rapidly in speed from the beginning as when the tube was 15-25 m. in length the flames now travelled from the point of ignition a t a constant and com-paratively slow speed over a distance of between 12 and 15 m. (dependent ‘on the composition of ths mixture) and then began to vibrate. The vibrations acquired their greatest amplituGe about half-way along the tube and continued throughout the remaining distance. I n mixtures containing between 9.5 and 10.5 per cent. of methane the speed of the flame over the first 12-15 m. averaged 200 cm. per second. Thus the records obtained over this range of mixtures were : Methane Initial speed of flame.per cent. Cm. per second. 9.60 198 9.70 188 9.75 203 10.10 213 This speed is a little faster than that of the uniform movement in similar mixtures in the sam0 tube (170 crn. per second). The important point is however that the speed should remain constant over so great a distance. Although open a t both ends a long tubs is thus found t o impress upon a flame started a t one end oonditions similar to those obtaining with a shorter t u b c l o d a t the distal end. The resistance to the expansive force of the burning gases afforded by the long column of unburnt mixture in advance of the flame corresponds (nearly) in effect with the resistance) of a closed end; so close is the correspondence that the flame is caused to proceed a t the outset with a (( uniform movement,” but little faste 46 MASON AND WHEELER THE PROPAGATION OF than the uniform movement as ordinarily developed in mixtures of the same methane-content in a tube of the same diameter.Photographic Analysis of the Flames. I n Plate 1 are shown time-distance curves obtained photographi-cally for the propagation of flame in a 10 per cent. mixture of methane and air in a tube of brass 5 cm. in diameter and 240 cm. long. The flames travelled horizontally from right to left and the photographic film can be regarded as moving vertically upwards its speed of travel being 30 cm. per second. The full length of the tube 240 cm. is shown in the photographs each of which is com-posite being obtained by joining together photographs of successive sections of the tube 30 cm.in length. For Fig. 1 the tube was closed a t the left-hand end and ignition was a t the right-hand open end; folr Fig. 2 the tubfe was open a t both ends and ignition was a t the right-hand end; and for Fig. 3 the right-hand end of the tube was closed and ignition was effected there the left-hand end being open. The relative speeds at. which the flame traversed the full length of the tube are! readily deduced from these photographs which also illustrate the' general behaviour !of the flames under ths different con-ditions of ignition of the mixtures and require no. description. It should be noted however that Fig. 3 discloses the presence of rapid vibrations during the progress of the flame which as stated earlier in this paper was judged by visual observation to travel unchecked through the tube a t a speed which according to determinati'ons by the screen-wire method seemed to be nearly uniformly accelerated.I n Plates 2 and 3 details of the flames as they passed through a section of the tube 30 cm. in length are shown the section chosen being that indicated in Plate 1 by the vertical white lines. To obtain these photographs the speed of the film was increased to 90 cm. per second. Calculations made from them are as follow : PLATE 2. T u b closed a t one end; ignition a t o p n end. Mean speed of flame . . . . . . . . . 246 cm. per sec. Maximum speed during forward rnove-ment of vibration . . . . . . . . . 1,990 cm. per sec. Average frequency of vibrations ... 76 The calculated frequency f o r the fundamental tone of the tube during the longitudinal vibration of air within i t is 68 i f ths lengt PLATE 1 PLATE 2 FIG.1. FIG. 2. PLATE 3 FLAME IN MIXTURES OF METHANE AND AIR. PART I. 47 of the vibrating column be assumed to be 125 cm. and 88 if 95 cm. These are the distances of the flame-front from the closed end of the tube a t the beginning and end of the photograph respectively. The mean value is 78. PLATE 3 FIG. 1. Tube open a t both ends; ignition a t one end. Mean speed of flame . . . . . . . . . 480 cm. per sec. Maximum speed during forward rnove-ment of vibration . . . . . . . . . 3,730 cm. per Bec. PLATE 3 FIG. 2. Tub,e closed a t one end; ignition at closed end. Mean speed of flame . . . . . . . . . 1,050 cm. per sec.ment of vibration . . . . . . . . . 5,760 cm. per sec. Maximum speed during forward move-Amplitude of vibrations . . . . . . 30 cm. Of the three conditions under which the ignition of mixtures Qf methane and air has been effected in these experiments that whlch would lead to the most disastrous results in industry is the third-ignition a t one end of a tube or gallery open a t both ends. For although the initial speed of the flame is not then so great as when ignition is a t a closed end continued propagation is assured and there may be developed momentarily during the vibratory motion velocities and pressures as great as any produced throughout the life of a flame started a t a closed end. The fastest speed of flame recorded in any experiment was about 60 m. per second and was of short duration. This is not of the same order of magnitude as the speed of the detonation-wave in gaseous mixtures. It would not be wise t o conclude however that the detonation-wave cannot in any circumstances be developed in mixtures of methane and air a t normal temperature and pressure. On the contrary in several experiments in the steel tube 90 m. lsong and open a t both ends in which restrictions were introduced a t two points (consisting of steel rings which reduced the diameter of the tube to 28.6 cm. a t those points) the development of the detonation-wave seemed imminent. Further description of these experiments which are being continued is reserved until the subject of the effects of turbulence on the propagation of flame in gaseous mixtures is discussed. ESKMEALB, CWBERLAND. [Received December 4th 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700036

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

48 PAYMAN THE PROPAGATION OF FLAME IN VI.-The Ppopagatiort- of Flame in Complex Gaseous Mixtures. Part I V. The Uniform Movement of Flame in Mixtuq*es of Methane, Oxygen and Nitrogen. ‘‘ Maximum-speed Mix-tures” of Methane and Hydrogen in Air. By WILLIAM PAYMAN. IT is customary to describe the inflammation of a gas mixture containing hydrogen and oxygen for example as the “ burning of hydrogen in oxygen.” This phrase is purely a relative one it being of course equally correct to regard the combustion as the burning of oxygen in hydrogen. Thus the upper limit of in-flammability of hydrogen in oxygen is the lower limit of inflammability of oxygen in hydrogen. Mixtures of a combustible gas with air can be considered in a similar way. I f however we state that the combustible gas, hydrogen for example is burning in air the alternative expression would be that the oxygen is burning in a mixture of nitrogen and hydrogen.A comparison can in fact be made over a range of inflammable mixtures between hydrogen and air on the one hand, and on the other mixtures of oxygen with a mixture (or “ atmo-sphere ”) containing nitrogen and hydrogen in constant pro-portions. For all practical purposes atmospheric air may be regarded as a mixture of oxygen and nitrogen in constant proportions. To investigate thoroughly the mode of combustion of complex in-flammable gas mixtures it is evidently desirable to examine their behaviour with atmospheres ” other than air the simplest problem being no doubt the combustion of a pure inflammable gas such as methane in pure oxygen.The uniform movement during the propagation of flame in mixtures of methane with different atmospheres containing less oxygen than air has been examined by Mason and Wheeler (T., 1917 111 1044). The present research deals with mixtures con-taining more oxygen than air and with mixtures with pure oxygen. The detonation-wave in such mixtures has been studied by Dixon (Phil. Trans. 1893 184 97). The speed of propagation of flame by detonation is of a different order from that during the initial, uniform movement of flame which is supposed to be mainly effected by the conduction of heat from the burning to the adjacent unburn COMPLEX QASEOUS MIXTURES. PART N. 49 layer of gas mixture. The speed of the detonation-wave is however, uniform.The two modes of propagation of flame “uniform move-ment ” and ‘‘ detonation-wave,” may be compared with respect to mixtures of hydrogen and air. The speed of the detonation-wave in the mixture of air with hydrogen containing the correct pro-portions for complete combustion is 1930 metres per second in a tube 9 mm. in diameter (value extrapolated from those determined by Dixon Zoc. c i t . ) whilst the speed of the uniform movement of flame in the same mixture (in a horizontal glass tube 2.5 cm. in diameter) is 4.8 metres per second (Haward and Otagawa T., 1916 10.9 83). Maximum-speed Mixtwes.-If we neglect losses of heat to the walls of the containing vessel the speed of propagation of flame during the uniform movement can be regarded as depending mainly on two factors namely (1) the rate of conduction of heat from layer to layer of the mixture which in turn depends on the difference in temperature of the burning and the unburnt gases and on their thermal conductivities and (2) the rate of reaction of the combining gases which for a given combustible gas will vary with the composition of the mixtures (presumably according to the usual laws of mass action) and with the temperature pro-duced by the reaction.A third factor might be added namely, the ignition-temperature of the mixtures but this is perhaps dependent on the other factors. The mixture of hydrogen and air for complete combustion that. is to say the mixture having the greatest heat of combustion, contains 29.6 per cent. of hydrogen but the mixture in which the speed of the uniform movement of flame is greatest contains about 38 per cent.or nearly 10 per cent. in excess. This fact is usually explained by reference t o the high thermal conductivity of hydrogen which is 31.9 x 10-5 as compared with 5-22 x 10-5 for air. A similar displacement of the maximum-speed mixtures is, however observed with all inflammable gases when mixed with air including (as was shown in Part I11 of this series of papers) gases such as carbon monoxide the thermal conductivities of which are less than that of air.* Consider the effect of mass action when methane burns in a given atmosphere of nitrogen and oxygen. Let this atmosphere contain a per cent. of oxygen. According to the law of mass action the rate of reaction will be proportional to CCHc x CZo1:.Let the mixture in which the rate has its maximum value contain 2- per cent. of methane. * The value for the thermal conductivity of carban monoxide i s 4.99 x 10-50 Then PAYMAN THE PROPAGATION OF FLAME IN CCH( x Po = x) x (100 - 2)-> ( C 100 l2 Since a is constant the term into which it enters will be at a maximum when z(lOO-x)2 is a t a maximum. That is to say, provided it remains constant the composition of the atmosphere does not affect the methane content required to give the expression CC‘H+ x Po its maximum value. It can be shown that this ex-pression reaches a maximum when x the percentage of methane, is 33.3. Similarly with hydrogen and any atmosphere of oxygen and nitrogen of constant proportion the factor representing the effect of mass action is a t a maximum when the mixture contains 66.7 per cent.of hydrogen. I n every instance with a given atmosphere when this remains unaltered the maximum effect of the mass-action factor is theoreti-cally attainable with mixtures containing more combustible gas than is required- for complete combustion (except with an atmosphere of pure oxygen when the mixture for complete combustion is also, theoretically that for the maximum effect of mass action). The rate of chemical reaction increases rapidly with rise of temperature. I n a series of mixtures of a combustdble gas with an atmosphere of constant composition the highest calorific effect is produced by the mixture containing combustible gas and oxygen in combining proportions.This factor will therefore act in an opposite sense to mass action and will diminish the “displace- . ment ” of the maximum-speed mixture caused by the latter factor. For this reason the amount of displacement will be influenced by the cooling effect of excess of combustible gas and the higher the specific heat of this excew gas at the temperature of reaction the less will be the displacement.“ When oxygen burns in an “atmosphere” of constant composi-tion composed of nitrogen and a combustible gas the displacement of the maximum mixture should take place towards mixtures con-taining excess of oxygen. This can be tested experimentally. Just as the whole series of inflammable mixtures of methane and air can be obtained by starting with the mixture containing the reacting gases in combining proportions and adding either methane or air to it in the same way a series of mixtures of oxygen with an “atmosphere” of nitrogen and methane can be obtained, by adding excess of oxygen or excess of “atmosphere” to the * This consideration accounts for the wider “ displacement ” obtained with carbon monoxide than with hydrogen when mixed with air COMPLEX GASEOUS MIXTURES.PART IV. 51 mixture of methane and air in combining proportions which may be termed the " basic mixture." This procedure has the advantage of enabling a direct comparison to be made between methane-air and oxygen-" atmosphere " mixtures the two series having a common point. The results of two such series of determination of the speed of the uniform movement of flame in mixtures of oxygen with (i) an atmosphere of nitrogen and methane and (ii) one of nitrogen and hydrogen are given in table I.The determinations were carried out in a horizontal glass tube 1-5 metres long and 2-5 cm. in diameter. TABLE I. Speed of Uniform Movement of Flame in Mixtures of Oxygen with Mixtures of Constant Composition (" A tmospheres ") of iVitrogen and a Combustible Gas. Methane as the combustible gas. Hydrogen as the combustible gas. Basic mixture 9.5 per cent. CH,; 19-0 per cent. 0,; 71.5 per cent. N,. Methane. Per cent. 6.67 7.61 8.29 8.75 9.07 9-18 9.50 9.67 Oxygen. Per cent. 43.3 46.2 39.5 25.6 22.9 22.0 19.0 17-8 Speed. Cm. per sec. 36.0 61.9 84.3 97-3 91.4 85-4 66.7 37.5 ,-Basic mixture 29.6 per cent.H,; 14.8 per cent. 0,; 55.6 per cent. N2-Hydrogen. Oxygen. Speed. Per cent. Per cent. Cm. per sec 16.06 53.7 171 21-76 37.3 488 25.72 25-9 660 29.60 14.8 410 30-50 12.2 234 It will be seen that the displacement of the maximum-speed mixture in both series of experimentkl as anticipated is towards mixtures containing an excess of oxygen. In table I1 the dis-placements are compared with those found with the combustible gases burning in air. TABLE 11. Displacement of Maximum-spe ed Mixtures . Methane. & OS-N CH4-N, constant. constant. Methane. Oxygen. Per cent. Per cent. Mixture for maximum speed of Mixture in combining propor-Displacement . . . . . . . . . . . . . . uniform movement of flame 9.9 34.8 tions.(Basic3 mixture) ...... 9-6 19.0 0.4 5.8 Hydrogen. A7 OS-N HS-N, constant. constant. Hydrogen. Oxygen. Per cent. Per cent. 38.5 23.4 29-6 14-8 8.9 8-52 PAYMAN THE PROPAGATION OF FLAME IN The addition of either combustible gas or oxygen to the basic mixture results in an increase in speed of the flame. According t o the laws of mass action it would be expected that the displacement would be greater on the addition of oxygen than on the addition of methane (since one molecule of methane combines with two mole-cules of oxygen for complete combustion); this is found to be so. The displacement should be less wit?h oxygen than with hydrogen (since two molecules of hydrogen combine with one molecule of oxygen) ; experiment again shows this deduction to be correct.The fact that the specific heat of oxygen is lower than that of methane and much lower than that of hydrogen however would have the effect of decreasing proportionally the amount of displacement caused by excess of either of the two last-named gases. Thus the displacement caused by the addition of oxygen is found to be much gIeater than that caused by methane but only a little less than that caused by hydrogen.* The Uniform Movemeizt of Flame in Mixtures of Methane, Oxygen and Nitrogen. The speeds of the uniform movement of flame in mixtures of methane with atmospheres containing 13-7 21 33 50 66 and 100 per cent. of oxygen have been determined. The experiments were carried out in a horizontal glass tube 2.5 cm.in diameter, as used for earlier experiments. A comparatively short tube, 1.5 metres in length was used in order to avoid the development of the detonation-wave. With the fastest speeds of flames how-ever the detonation-wave was developed after the flame had travelled less than a metre so that for some of the experiments i t was necessary to replace the last metre of the glass tube by a piece of lead piping of the same length and internal diameter. Only the slowest speeds up to about 300 cm. per second were determined by means of the automatic commutator and single recording stylus usually employed €or such work in this labora-tory; for faster speeds recourse was had to delicate Deprez indicators with separate styli for each screen-wire recording on a smoked paper chart fixed to a rapidly revolving drum.The fastest speeds in mixtures of methane with pure oxygen were determined photographically by the method described by Mason and Wheeler (T. 1919 115 578). A comparison between the two last-named methods of recording speeds of flames gave closely agreeing results. The results of the determinations are given in table 111 and * These experiments explain why the displacement of the maximum-speed mixture was found to be so small with the mixtures of producer gas and air, as described in Part 111 TABLE 111. Speed of Uniform Movement of Flame in Mixtures of Methane with Oxygen in a Horizontal Glass Tube 2.5 cm. Atmosphere. 13.7 per cent. 0,. 7 Per cent. CH,. 6.33 6.41* 6.70 6.90 7.02 - Speed (om.per sec.). Flame about I6 om. 21.9 21.0 19.1 Flame about 6 cm. Atmosphere. 33 per cent. 02. 7 Per cent. CH,. 6-69 6.78 6.87 8-44 11-01 14*58* 18.01 21-51 25.12 25.41 -'-Speed (cm. per sec.). Flame about 10 cm. 23.0 23.9 97.6 168 232 200 49.1 18.9 Flame about 15 cm. Atmosphere. 50 per cent. 0,. & Per cent. Speed CH,. (cm. per sec.). 5-70 Flame about 8-83 22.8 9.60 160 12-48 40 1 15-38 735 19*84* 967 24.01 711 28-47 171 33-58 44 38.78 18.9 39-26 Flame about 15 cm. 16 cm. Per CH,. 5.70 5.84 8.79 11-15.07 18-25* 29.29 34.65 40.02 46.93 47-47.6 54 PAYMAN THJG PROPAGATION OF FLAME diagrammatically in Pig. 1. For the values for mixtures with air, reference should be made t o the table in P a r t 11 (T.1919 115, 1448). The mixture marked with an asterisk in each column is that which contains methane and oxygen in combining proportions. Fig. 1 may be compared so far as its general characteristics are concerned with the similar diagram given by Mason and Wheeler (loc. cit. p. 1048) for mixtures of methane with atmospheres con-taining less oxygen than air. It should however be noted that these authors determined the speeds in a tube 5 cm. in diameter. The most striking results are those for mixtures of methane with FIU. 1. Methane per cent. pure oxygen. It will be seen that the maximum speed of the uniform movement of flame is obtained as was anticipated with the mixture containing methane and oxygen in combining propor-tions (CH,+20,).This result is in sharp distinction from what obtains when the detonation-wave is developed in mixtures of methane and oxygen for the mixture in which the speed of the detonation-wave is greatest contains equal proportions of methane and oxygen. The difference is the more striking when it is remem-bered that the uniform movement gives place to the detonation-wave after quite a short distance of travel of the flame [ To face p. 54 COMPLEX OASEOUS Ml’STUSb!S. PART 1V. 55 In table I V a comparison is made between the speed of the uniform movement and that of the detonation-wave in the five mixtures used by Dixon (Zoc. cit. p. 181). TABLE IV. Comparison of the Speeds of the Detonation-wave and the Uniform Movement in Mixtures of Methane and Oxygen.Composition of mixture. 2CH + 80s 2CH4 + 60, 2CH4 + 402 2CH4+ 30, ZCH,+ 202 Speed metres per second. - Detonation wave. Uniform movement. Tube 2-5 cm. diam. Tube 0.9 cm. diam. 1963 18 2146 33 2322 66 2470 25 2528 2 The addition of methane to the mixture for complete combus-tion (CH,+20,) is thus seen to increase the speed of the detonation-wave but markedly to decrease the speed of the uniform movement of flame. This effect is well illustrated by photographs of the flames (1) in a mixture containing just sufficient oxygen for complete combus-tion of the methane and (2) in a mixture containing rather more methane (40 per cent.). In the latter mixture (Fig. a) the uniform movement persisted over about 25 cm.of travel of the flame which then vibrated rapidly for a short time (0.06 sec.) without moving further along the tube. The vibrations were followed by a rapid acceleration of the flame resulting in the detonation-wave which shattered the glass tube a t about 25 an. distance from the lead extension piece. The bright band at the bottom of the photograph is caused by the ‘ I retonation-wave.” * Although the speed of the uniform movement of flame is slower in a mixture containing 40 per cent. of methane than in one con-taining 33 per cent. the detonation-wave is developed sooner in the former. With the 33 per cent. mixture the uniform move-ment extends across the whole width of the photograph (Fig. 3). The incidence of the detonation-wave a short distance further along the tube (within the lead extension piece) is indicated by the bright band due to the retonation-wave a t the bottom of the photograph.f * A compression-wave sent back simultaneously with the development of the detonation-wave through the burnt or still burning mixture (Dixon, Phil. Trans. 1902 200 316). t The length of tube photographed wag 30 cm. and the speeds of the film were 692 and 762 om. per second for Fig. 2 and Fig. 3 respeotively $6 PAYMAX THE PROPAGATION OF FLAME IN It must be admitted that the displacement of the maximum-speed mixture away from that required for complete combustion is not! very great in mixtures of methane and air. A better test) of the soundness of the coriclusion that with pure oxygen the maximum-speed mixture and the complete-combustion mixture should coincide should be obtained with a combustible gas like hydrogen.With this gas it will be remembered the maximum-speed mixture with air is displaced by as much as 10 per cent. Experiments were theref ore made with mixtures of hydrogen and pure oxygen. Three mixtures were examined and the speeds are recorded in table V with the speeds of the detonation-wave in the same mixture for comparison. TABLE V . Comparison of the Speeds of the Detonatiowave and the Uniform Movement in Mixtures of Hydrogen and Oxygen. Speed metres per sec. - -. Hydrogen. Detonation-wave. Uniform movement. Tube 2.5 cm. dirtm. Per cent. Tube 0.9 cm. &am. (Dixon). 59.9 66-6 75.2 2650 2824 3140 5-74 6.62 5-16 Fig.4 and Fig. 5 are the photographs of the flames in the mixtures containing 75.2 per cent. and 66.6 per cent. of hydrogen respectively.* It will be seen that the photographs are similar in general character to those obtained with the two corresponding mixtures of methane and oxygen. To revert to the experiments with methane the addition of either methane or oxygen like that of the inert gas nitrogen to the mixture of methane with pure oxygen of the composition CH + 20, results in a reduction of the speed of the uniform move-ment of flame. The relative effects of these three gases are shown in Fig. 6. Methane having the highest specific heat of the three, has the greatest retarding effect. Although oxygen and nitrogen have approximately the same specific heat the retarding effect of the former is appreciably less owing to the effect of mass action when the gas added is capable of taking part in the reaction.The application of the “speed generalisation ” was shown in earlier papers to be restricted by the fact that the only data avail-* The speeds of the films were 784 and 816 cm. per second for Fig. 4 rtnd Fig. 6 respectively COMPLEX GASEOUS MIXTURES. PART I V . 57 able for use in the calculations were those respecting mixtures of inflammable gas% with air. Thus with methane-hydrogen-air mixtures no calculations could be made for mixtures in which the speed of flame was greater than 67 cm. per second the maximum speed in mixtures of methane and air. The speeds now obtained in mixtures of methane with atmospheres containing more oxygen than air are often greater than the maximum speed with hydrogen-air mixtures so that the use of these values should render it FIG.6. Gm added to the mixture CH + 20, molecules. possible to calculate the speeds of the uniform movement; of flame in any methane-hydrogen-air mixture. For this purpose however it would be necessary t o determine the speed of flame in mixtures of hydrogen with different atmo-spheres in the same way as has been done for methane and for similar calculations Go be made for mixtures of an industrial gas with air similar determinations would be required for each individual gas present in the industrial gas. Such a series of determinations is outside the scope of the pre-sent work. It is however important to establish the fact that the “speed generalisation” is capable of extension in this manner 58 PROPAGATION OF FLAME IN COMPLEX GASEOUS MIXTURES.To this end a few determinations have been made for methane-hydrogen-air mixtures. To simplify the calculations mixtures of methane and hydrogen with just sufficient air for complete combustion were chosen. A curve similar to the one in Fig. 6 for CH,+20,+zN2 was con-structed for hydrogen (2H + 0 + d,). I f mixtures are selected from these two curves in which the speed of flame is the same and is intermediate between the maximum speeds in methane-air and hydrogen-air mixtures it is possible to mix them in such propor-tions that the resulting mixtures will contain nitrogen and oxygen in the ratio in which they are found in air. This mixture will have the same speed of uniform movement of flame will contain combustible gas and oxygen in combining proportions and will be, in a sense a methane-hydrogen-air mixture. In this way it is possible t o determine the speed of flame in all mixtures of methane and hydrogen with sufficient air for their complete combustion. The results of such calculations with three simple mixtures are recorded in table VI. Speed of TABLE VI. Uniform Movement of FZame. Cm. per sec. Hydrogen-Me theno mixture. Calculated. - From curves. 9 From formula. 85 90 95 135 140 149 240 250 246 Found. The results recorded in the last column are obtained by use of a formula similar to the one used in P a r t I1 (T. 1919 115 1452) for calculating the ma,ximum-speeds of flame in mixtures with air, ‘‘ mixture for complete combustion ” being substituted for ‘‘ maximum-speed ” mixture. The experimental work described in this series of papers was carried out at the Home Office Experimental Station under the general direction of Dr. R. V. Wheeler. ESKDALS, CUMBERLAND. [Received November 12th 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700048

出版商:RSC    

年代:1920

数据来源: RSC

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THE SOLUBILITY OF SULPRUR DIOXIDE ETC. 59 VII.-The Solubility of Sulphur Dioxide in Sulphuric Acid. By FRANK DOUGLAS MILES and JOSEPH FENTON. IN the course of some work on the gas-purifying system of a plant for the manufacture of sulphuric acid by the '' contact " process it was noticed that 95 per cent. sulphuric acid dissolved more sulphur 55 60 65 70 75 80 86 90 95 100 2.8 Percentage of H2S04 in aeid. dioxide than did acid of 85 per cent. The solubility in more dilute acid diminishes in the usual manner as the concentration increases, so that the observation pointed to some peculiarity in the solubility curve for higher concentrations of acid. A determination of th 60 THE SOLUBILITY OF SULPHUR DIOXIDE ETC. Sulphur dioxide dissolved by 100 Sulphuric acid. grams of acid. Per cent. Grams. 55- 1 5-13 59.6 4.90 61.6 4-82 68.9 4.1 6 74.1 3.63 78.3 3.23 80.2 13-12 82.5 2.99 84.2 2-88 85.3 2.83 85.8 2.80 86.5 12.82 Sulphur dioxide dissolved by 100 Sulphuric acid. grams of acid. Per cent. Grams. 88.1 2.9 90.8 3.10 92.8 3.2 1 93.7 3.27 94.0 3.31 94.6 3.50 95.5 3.69 95-6 3.77 96-5 3.83 98.0 3-98 98.5 4.03 - SEN AND GHOSH PHLOROACETOPHENONE. 61 'L'he solubility reaches a minimum value in sulphuric acid of 86.0 per ceut. and from that point the curve inclines very sharply upward for either increase or decrease in percentage of sulphuric acid. It is significant that acid of 84.5 per cent. has the composition of the hydrate H,SO,.H,O and that in the neighbourhood of this point the temperature of melting and other physical properties pass through critical values. [Received Decernbey 1 8th. 19 19.

ISSN:0368-1645    

DOI:10.1039/CT9201700059

出版商:RSC    

年代:1920

数据来源: RSC

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SEN AND GHOSH PHLOROACETOPHENONE. 61 VII I.-Phlo~oacetophenor~e. By KIEMUD BEHARI SEN and PRAPHULLA CHANDRA GHOSH. PHLOROACETOPHENONE is an important compound for the synthesis of many natrural dyes (Goschke and Tambor Ber. 1912 45 1237). Biilow and Wagner obtained it by first condensing phloroglucinol with benzoyl chloride and then degrading the resulting ppranol (Ber. 1901 34 1'798). Leuchs and Sperling (Ber. 1915 48 135) prepared i t by the action of water at 170° on Jerdan's lactones (T., 1897 71 1111). I n no case was the direct synthesis achieved. Resacetophenone gallacetophenone and similar compounds are easily and directly prepared from the corresponding phenols by heating them with acetic acid and zinc chloride. It was therefore thought that phloroglucinol on similar treatment might give phloro-acetophenone and thus a direct synthesis might be effected.When, however phloroglueinol is heated with acetic acid and zinc chloride there is produced a yellow crystalline compound dissolving in potass-Y 62 SEN AND GHOSH PHLOROACETOPHENONE. ium hydroxide solution with a pink colour and fluorescence. From the analysis and the determination of the molemlar weight by the ebullioscopic method in alcohol it is concluded that phloroaceto-phenone is first formed but that two molecules a t once combine, giving a pyrm derivative resembling Nencki's resacetein (p. 61). On boiling the pyran derivative (I) with 10 per cent. sodium hydroxide solution the heterocyclic ring is broken and phloroaceto-phenone (11) is obtained. The melting point of phloroacetophenone was found to be 284-285O; according to Bulow and Wagner it does not melt up to 280° and Leuchs and Sperling give 2 1 8 O .The substance obtained by the latter authors contained one molecule of water of crystallisa-tion which may account for the difference in melting point. E X P E R I M E N T A L . 5 7-Dih ydroxy-2 -0-0-p- trihydrox y pheny 1 -4-me t h y lene-l ; 4- b enzo-Two grams of phloroglucinol were dissolved in 2 C.C. of glacial acetic acid 3 grams of zinc chloride added and t.he whole was gently boiled for ten to fifteen minutes. The yellow liquid was dissolved in hot hydrochloric acid and the clear solution on cooling deposited yellow needles (0.9 gram). The substance is soluble in alcohol and dissolves in potassium hydroxide solution giving a pink fluorescent solution.PYran (1). It does not melt up to 290O: 0.1256 gave 0.2751 CO and 0.0502 H20. C=59.7; H=4.45.* 0.5713 in 18 C.C. alcohol gave E=0*18O. M.W.=275. Cl,Hl,0G,H20 requires C = 60.3 ; H = 4.4 per cent. M.W. = 300. Acetyl Derivative.-One gram of the above compound 10 C.C. of acetic anhydride and a few drops of pyridine were boiled gently for an hour. The semi-solid mass obtained on pouring into water was dissolved in acetic acid and precipitated with water being finally crystallised from dilute acetic acid. The compound melts a t 80° and begins to decompose a t about 90°: 0*1202 gave 0.2680 CO and 0.0560 H,O. C=60*8; H=5*1. C2,H220, requires C = 61.16 ; H=4*31 per cent. Yhloroacetophenone (11). Three grams of the pyran were dissolved in 75 C.C.of 10 per cent. sodium hydroxide solution the solution boiled for ten t o twelve minutes and after cooling acidified with dilute hydrochloric acid. The precipitate was collected dried and finally crystallised from WORSLEY AND ROBERTSON THE PEROXIDES OF BISMUTH. 63 mixture of alcohol and dilute hydrochloric acid. The product (0.8 gram) was almost colourless and dissolved in potassium hydroxide solution with only a pale yellow colour. It melted a t 284-285O. (Found C=56*44; H=5*2. C,E,O requires C=67*1; H=4*8 per cent .) Yhenylhydrazone.-This was prepared in the ordinary way by dissolving the phloroacetophenone in a mixture of alcohol and acetic acid adding a little more than the theoretical quantity of phenyl-hydrazine hydrochloride and sodium acetate and warming for a few minutes. To the clear solution water was added and the precipi-tate was collected dried and finally crystallised from dilute alcohol. It decomposes a t 237-2+0°: 0.1150 gave 11.65 C.C. N a t 32O and 761 mm. CHEMIOLL LAI~ORATORIES, N=11-3. CI4Hl4O3N2 requires N = 10.8 per cent. DACCA AND PRESIDENOY COLLEGE, BENGAL INDIA. [Received July 31st 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700061

出版商:RSC    

年代:1920

数据来源: RSC

摘要:

WORSLEY AND ROBERTSON THE PEROXIDES OF BISMUTH. 63 IX.-The Peroxides of Bismuth. By RICHARD ROBERT LE GEYT WORSLEY and PHILIP l%71LFRED ROBERTSON. THE most comprehensive and recent work on the peroxides of bismuth is by Gutbier and Bunz (Zeitsch. anorg. Chem. 1906 48, 163 295; 49 433; 50 211). These observers from their experi-ments on the oxidation of bismuth hydroxide in the presence of alkali hydroxide drew the conclusion that chemical compounds could not be isolated from the mixtures thus obtained even after subsequent treatment with nitric acid. It seemed however prob-able that continuous grinding with dilute nitric or glacial acetic acid might bring about a separation of the lower oxide of bismuth from the peroxide. Accordingly preliminary experiments were carried out in which ( a ) bismuth hydroxide precipitated in the oxidising medium and ( 6 ) ordinary bismuth trioxide were treated with ammonium persulphate in boiling dilute sodium hydroxide solution.The first product was comparatively rich in bismuth peroxide but its composition altered only little after grinding with glacial acetic acid; the product in the second case contained less peroxide but after several grindings its composition approximated to that of bismuth tetroxide. Experiments were therefore mad 64 WORSLEY AND ROBERTSON THE PEROXIDES OF BISMUTH. in this manner with different oxidising agents in the presence of sodium or potassium hydroxide of different concentrations. In dilute solutions bismuth tetroxide was the only product; in more concentrated solutions higher oxides were also formed.These products were analysed in the following manner the peroxidic oxygen was estimated ( a ) by distillation with hydrochloric acid (Bunsen’s method) ( b ) when the substance was soluble by dis-solving in hot nitric acid (D 1.2) and measuring the liberated oxygen; the peroxidic oxygen plus water was determined by heat-ing t o redness. The compounds for which analytical results are given below were free from sodium or potassium. Action of Chlorine on Bismuth Trioxide suspended in Boiling A 1 kali Hydroxide. The product of the reaction in dilute solution (5-10 per cent.) was either BkO (brown) or Bi,O,,H,O (brown). The exact conditions determining the formation of the anhydrous oxide or the hydrate could not be ascertained.In concentrated alkali hydroxide (35-40 per cent.) there was formed a mixture of Bi205,H20 (red) and Bi,0,,2H20 (yellow) from which the lower oxide could be fractionally separated by the action of hot nitric acid (D 1.4). The following values were obtained in one typical experiment for a mixture ( A ) after two grindings with glacial acetic acid; ( B ) after three grindings with glacial acetic acid; (C) after one extraction with hot nitric acid; ( D ) after two extractions with hot nitric acid: A . B. C. D. Peroxidic-0 ........................ 5.20 6-05 3.94 3-47 Peroxidic-0 + H,O ............... 10.05 10.02 9.97 10.00 The duration of each experiment was about half an hour. Bi20,,2H,0 requires 0 = 3.10 ; 0 +H,O = 10.08 per cent. Bi,O,,H,O requires 0 = 8-22 ; 0 +H,O = 9.73 per cent.According to Deichler (Zeitsch. anwg. Chem. 1899 20 lll), the product of the reaction should be a mixture of Bi,O and Bi,0,,H20 and the Bi20,,2H,0 is produced by the action of nitric acid on the latter. The colour of the substance A (orange-red), the analytical results and its behaviour with nitrio acid all indicate that it was a mixture of Bi,O,,ZH,O (yellow) and Bi205,H,0 (red). Action of Ammonium Persulphate OT Potassium Ferricyani.de on Bismuth Trioxide suspended in Boiling Alkali Hydroxide. The product of the reaction in dilute solution was either Bi,O, (brown or purplish-black) or Bi,04,H20 (brown or purplish-black) WOB8LEY AND ROBERTSON THE PEEOXIDES OF BISMUTH. 65 The experimental conditions determining the formation of these four varieties could not be ascertained.I n concentrated alkali there was formed in addition to Bi,O or Bi,O,,H,O a small amount of Bi,O (yellow) which could be fractionally separated from the lower oxide by the action of hot nitric acid (D 1 - 2 ) . Bismuth Tetroxide Bi,O,(BiO,). This was prepared by the action of chlorine ammonium per-sulphate or potassium ferricyanide on bismuth trioxide suspended in a dilute solution of boiling alkali hydroxide and the following modifications have been obtained I Bi,O (brown); 11 Bi20, (purplish-black) ; 111 Bi,O,,H,O (brown) ; IV Bi,O,,H,O (purplish-black) . The following are typical analyses for preparations which had been ground with glacial acetic acid in an agate mortar until they were completely free from bismuth trioxide and occluded alkali hydroxide : I.11. Bi,O,. Peroxidic-0 ............... 3.31 3-26 ; 3.20* ; 3.39 3.33 per cent. Loss on heating ............ 3.27 3.24 3-61 3-33 ,, 111. IV. Bi204,H20. Peroxidic-0 ............... 3.25 ; 3.07 3.13 ; 3.21 3.21 p0r cent. Peroxidic-0 + H,O.. ....... 6-88 ; 6.20 6-22 ; 6-92 6.83 ,, * Determined gasometrically. The brown and purplish-black anhydrous bismuth tetroxides appear to be physical isomerides and are both stable a t looo. The modifications with one molecule of water lose the water in a vacuum (1 mm.) over phosphoric oxide slightly darkening in colour. At looo in the steam-oven they lose half this amount : 111. IV. Loss at 100' ............... 1.70 1-74 1-89 Bi,O,,H,O requires hH,O = 1.81 per cent.A t 160° all varieties decompose with the liberation of oxygen. Bismuth tetroxide is soluble in nitric acid (D 1.2) at 70-90°, yielding its peroxidic oxygen in the gaseous form (with small quantities of ozone). It is peculiarly reactive immediately oxidising manganous salts in the presence of dilute nitric acid even in the cold. Bismuth tetroxide is very sparingly soluble in con-centrated alkali hydroxide with the formation of an unstable per-salt. Another distinct variety Bi,0,,2H20 (yellow) is formed, together with Bi,O,,H,O by the action of chlorine on bismuth VOL. cxvrr. 66 WORSLEY AND ROBERTSON THE PEROXIDES OF BISMUTH. trioxide in boiling concentrated alkali hydroxide. It may be fractionally separated from the higher oxide by treatment with boiling nitric acid (D 1-4) in which it is only sparingly soluble.The following analyses were obtained for two preparations : I. 11. Bi,O,,BH,O. Peroxidic-0 ............ 3.47 3.38 3.10 per cent. Peroxidic-0 +H,O.. .... 10.00 9.95 10.08 ,, At looo it decomposes darkening in colour with the loss of both oxygen and water. Bkmu t h Pent oxide Bi,O,. The monohydrate Bi,O,,H,O (red or brown) soluble with diffi-culty in hot concentrated nitric acid is obtained (a) mixed with Bi,04,2H,0 by the action of chlorine on bismuth trioxide in boil-ing concentrated alkali hydroxide ( b ) in small quantities mixed with Bi,04,H20 by the action of ammonium persulphate on bismuth trioxide in dilute alkali hydroxide at 40-60° when the action is allowed to continue for five to six hours.The bismuth pentoxide produced by the first method could not be separated from the admixed Bi,04,2H,0; obtained according to the second reaction it could be completely separated from the Bi,04,H20 by extraction with hot nitric acid (D 1.2). Three different samples gave the following values on analysis: Peroxidic-0 ......... 5.97 6.05 6-26 6.22 per cent. Peroxidic-O+H20. .. 9.80 - 10.16 9.73 ,, A second variety Bi,0,,H20 (brown) readily soluble in hot nitric acid (D 1.2) is obtained from commercial sodium bismuthate after repeated grinding with glacial acetic acid. The following analyses were obtained for three different preparations : Peroxidic-0 ......... 6*20* 6-19* 6-14 6.22 per cent. I. 11. 111. Bi,06,H,0. I. 11. 111. Bi,O,,H,O Peroxidic-0 + H,O... 10.00 9.91 9-96 9.73 ,, * Determined gasometrically. Anhydrous bismuth pentoxide would appear to be incapable of existence. The hydrate when left in a vacuum (1 mm.) over phosphoric oxide darkens in colour and slowly loses water and oxygen. A t looo the decomposition is more rapid; in one experi-ment the percentage of peroxidic oxygen fell from 6.2 to 1.9 in twenty days and subsequently remained constant indicating that bismuth trioxide and bismuth tetroxide had been formed in approximately equal amounts TEE ACTION OF MERCURTC CYANIDE ON METATLIC SALTS. 67 Bismuth Hexoxide Bi,0,(Bi03), Bismuth hexoxide is obtained in small quantities by the action of ammonium persulphate or potassium f erricyanide on bismuth trioxide suspended in boiling concentrated alkali hydroxide, together with bismuth tetroxide (Bi,O or Bi,04,H,0) from which it can be separated by continuous extraction with warm nitric acid (D 1.2). It may also be prepared by the oxidation of the tetroxide and subsequent treatment of the product with nitric acid. A t the ordinary temperature it loses oxygen slowly darkening in colour. This would explain the slightly low results obtained on analysis : Bismuth hexoxide is pale brown and contains no water. I. 11. Bi,O,,. PeroXidic-0.. . . . . 8.96 9.13 9.37 per aent. Loss on heating 9.00 9.1 1 9.37 ,, IMPERIAL COLLEUE OF SCIENOE AND TECHNOLOUY, SOUTH KENSMQTON. [Received November 6th 1919.

ISSN:0368-1645    

DOI:10.1039/CT9201700063

出版商:RSC    

年代:1920

数据来源: RSC