|
1. |
Abstracts of the Proceedings of the Chemical Society, Vol. 3, No. 35 |
|
Proceedings of the Chemical Society, London,
Volume 3,
Issue 35,
1887,
Page 39-46
Preview
|
PDF (550KB)
|
|
摘要:
ABSTRACTS OF THE PROCEEDINGS OF THE CHEMICAL SOCIETY. No. 35. Session 1886-87. Xarch 17th, 1887. Dr. Hugo Muller, F.R.S., President, in tlie Chair. Messrs. Hugh Robert Mill, Gerald T. Moody and Arthur Stanley were formallx admitted Fellows of the Society. Certificates were read for the first time in favour of Messrs. William C. T. Beasley, Honiton School, Devon ; Edwin Richardson Blund-stone, B.A., 10, Wellington Mansions, Regent's Park, N.W. ; Samuel Francis Burford, Halford Street, Leicester ; Henry Danber, Kenmore, Waterloo Park, near Liverpool ; William Gregory, Trent Valley Brewery, near Lichfield; T. 0. Sandell, 1, Baron's Court Road; Leonard Owen Simmons, Fareham, Hants ; Samuel Sutcliffe, Mostyn, North Wales. The following were elected Fellows of the Society :-Messrs.Earold G. Colman, James T. Cundall, Alfred J. Evans, Arthur Harden, William Houlding, Theophilus H. Redwood, George Robertson, W. H. Stanger, Patrick T. O'Sullivan, The following papers were read :-26. ''The Action of Heat on Nitrogen Peroxide." By Dr. A. Richardson, University College, Bristol. The dissociation of nitrogen peroxide has been investigated by Deville and Troost and other experimenters at temperatures between -12"and 180"; and it has been shown that while at low temperatures the molecule of the substance is represented by the formula N204, dissociation into nitrogeii dioxide, NOz, takes place with rise of tem-perature, being complete at 140". Experiments have been mdde by the author to determine the change 40 which takes place at temperatures above 140".On heating the per- oxide at about 500°, t,he gas becomes nearly colourless, and is found to consist of nitric oxide and oxygen : the presence of the former being indicated by the formation of the dark blue liquid which results from the interaction of nitric oxide with nitrogen peroxide when the ga8sis condensed ; and the presence of oxygen being demonstrated by the rekindling of a glowing match. At a temperature at which decomposition is complete, the change would be represented by the equation 2x0, = 2N0 + 0, ; the vapour-density of the dioxide being 0.23, that of the product is 15.3. On determining the density of the gas at temperatures between 130"and 500", the numbers obtained were in agreement with the formula NO, at 140",but as the temperature rose they more and more nearly approached that corresponding to complete dissociation.The curre representing the density of the gas at different temperatures shows that the decomposition of Nz04 into NO, is complete at 140°,and is immediately succeeded by the further dissociation of nitrogen dioxide into nitric oxide and oxygen. The form of the curve is that usually exhibited by dissociating substances, the change of density being most rapid at the temperature at which half the total number of molecules of the original substance are decomposed. 27. " Supersaturation of Salt Solutions." By W. W. J. Nicol, M.A., D.Sc. This paper contlains an account of experiments on the physical corstants of supersaturated and dilute salt solntions.The solutions were examined in two ways : lst, concentration constant and tempe- rature varying ; 2nd, temperature constant and concentration vary- ing ; in this way it was possible to pass from dilute to supersaturated solutions, and to examine the change in the various physical con- stants. The electric conductivity, specific viscosity and rate of expan-sion kere examined by the first metbod. The specific viscosiky and density by the second. In every case it was found that the curve corresponding to the non?sat,urated solutions was perfectly con-tinuous with that for tbe Supersaturated solutions. From this the author concludes that the constitution of dilute, saturated and supersaturated solutions is the same.Supersaturation is explained by the hypothesis that the substance in solution is not the same as that which crystallises out. A supersaturated solution of sodium thiosulphate deposited crystals of the composition Na,S,O,H,O when evaporated in vacuo, showing that the solution does not contain the pentahydrate. The author believes that the salt in solution is com- bined with the whole of the water, an opinion based on his experi- ments on vapour-pressures and molecular volumes. Colour changes in solution are not, he believes, due to hydration, but to rearrange-ments of the salt molecule similar to that which occurs in the case of chromium sulphate. DISCUSSION. Mr. PICKERINGsaid that he could not agree with Dr.Nicol in con-cluding that a supersaturated and non-supersatura ted solution have identical constitutions, or that the salt was not combined with the solvent. A large number of the physical properties of solutions, such as the volumes of the dissolved salt, the lowering of the freezing point, &c., appear not only to afford no evidence of the existence of combination between the salt and the solvent, but would even, if taken alone, show that the radicles composing the salt itself are not combined ; it was only by taking into consideration all the properties of solutions that we could obtain a correct conception of their nature. When examined from cerhain points of view, an ordinary and a super- saturated solution would, as Dr.Nicol shows, appear to be identical, but a study of the solubility of the salt leads to very different conclusions. Referring to the nature of solution, Mr. Pickering said that chemists universally recognised two different forms or degrees of chemical combination, atomic and molecular, the latter being in some cases so weak that when examined from certain points of view only we could obtain no evidence of any combination at all ; we should do well to consider the strong evideiice which a study of minerals, alloys, isomorphous crystals, &c., afford of a form of combination less inti-mate even than that of our molecular compounds. The true mole- cules of solids and liquids, he considered, consisted in all probability of a large number of our formula molecules united together, and in the same way the true molecules of a solution would consist of aggregates of a, large number of the molecules of the solvent with those of the salt, or of a definite molecular hydrate of the salt, according to circnm- stances, forming n unit of such complexity and instability that it would probably never exist entirely undissociated, and would therc- fore be affected in an apparently continuous manner by alterations in the physical conditions under which it existed (see Chem.News, 54, 215). Dr. ARMSTRONGquestioned the interpretat'ion which Dr. Nicol had given of the continuous curves by which his observations were graphically expressed. It a,ppenred to be established theoretically that a certain definite electromotive force, of more than a volt was required to electrolyse acidulated water ; but actually any E.M.P., however 42 small, was found to suffice, the reason being apparently that owing to the presence of dissolved air action took place in a contrary direction ; in like manner it was proba!ble that in many cases in which dissocia-tion was observed, if the effect of surfaces, &c., could be eliminated, the changes would be found to take place only suddenly, and would be represented by a broken, not by a continuous curve. The cases studied by Dr.Nicol were probably of the latter class, and if super- saturation took place gradually-part of the solution becoming super- saturated before even the whole was saturated, the curves representing the change in specific viscocity, &c., would necessarily be continuous.In discussing a problem such as that before the meeting, it was neces-sary to make a scientific use of the imagination and to consider the phenomena generally. Dr. NICOL said that Professor Pickering’s remarks more than ever convinced him that there was little or no difference in their views. Professor Pickering had abandoned the definite hydrate theory, and now believed in indefinite hydrate-aggregates of one molecule of salt and many hundred molecules of water. Where was the line to be drawn ? He (Dr. Nicol) believed at the number of water molecules present in the solution ; Professor Pickering stopped short of this, but where? As to the name to be applied to these aggregations, whether they should be called chemical or physical, he thought that according to the present use of the words the latter was the more appropriate.In reply to Professor Armstrong, Dr. Nicol pointed out that in an analogous case Wiedemann had found that the volume curve of hydrated salts exhibit’ed irregularities long before their melting points were reached, and that this pointed to a rearrange- ment of the molecules similar to what would occur in supersaturated solutions were the hydrated salt present. 28. “ The Formation of ApNaphthalenesulphonic Acid by means of Sulphuric Anhydride and on 01-Dihydroxynaphthalene.” By Henry E. Armstrong and W. P. Wynne, B.Sc. By sulphonating naphthalene by means of sulphuric anhydride- both substances being intimately mixed with sand before admixture, and then vigorously shaken together- the authors have obtained a disulphonic acid which they believe is identical with that prepared by means of S0,HCl (Proceedings, vol.ii, No. 27, p. 230). The sodium salt prepared from the product of the first experiment made at once crystallised in massive transparent diamond-shaped crystals of the oblique system ; all attempts to prepare similar crystals from the prodiict of the action of S0,HCl have been unsuccessful, the salt rom this ennrce being always obtained in characteristic thin plates ;and 43 in a second experiment with SO, the sodium salt produced cryetallised also in plates, distinct, however, in appearance, from those prepared from the S03HC1product, and this salt could not be caused to crystal- lise in the massive forms observed on t8he first occasion.Nevertheless it can scarcely be doubted that the acids prepared by the two methods are identical, as the snlphochloride from the SO, product has the same melt,inq point (182") as, and resembles in appearance, that from the S03HC1product, and both yield 7-dichloronaphthalene on treat- ment with PCl, ; the products of the action of bromine on the two sodium salts appear to be similar; and they behare alike on fusion with potassium hydroxide. The dihydroxynaphthalene formed on fusing y-naphthalenedi-sulphonic acid with potassium hydroxide would seem to be identical with that prepared by Clhe by Griess's method from the amido-acid formed by reduction of 1: 4' nitronaphthalenesulphonic acid.It melts at about 250" ; an alkaline solution on warming at once assumes a colour like that of a permanganate solution, but the colour rapidly changes to a, dirty brown. The authors express the desire to reserve the right of further investigating this dihydroxynaphthalene. 29. " a-CyanonaphthalenesulphonicAcid." By Henry E. Armstrong and S. Williamson. It being ascertained that on sulphonating the a-haloid-derivatives of naphthalene the products are the 1:4homonucleal sulpho-acid together with a small amount of a heteronucleal isomer, whereas on sulpho-nat,ing a-nitronaphthalene and naphthalene-a-sulphonic acid the 1: 4' heteronuclch di-derivative is alone formed, it became desirable to study the behaviour of other a-derivatives of naphthalene containing negative radicles. a-Cyanonaphthalene was first sulphonated by means of SO,HCl, but it was found advantageous to use fuming sulphuric acid instead ; there appears to be only one sulphonic acid formed.The barium and potassium salts crystallise in different forms according to the conditions, and with different amounts of water; the most characteristic form of the barium salt is a hexhydrated modification, [CloH6(CN) SO3I2Ba*GH20,which crystal- lises in long, thin, glistening plates ; at low temperatures the potas- sium salt separates in transparent prisms, which probably belong to the oblique systeni, of the formula C,,H6(CN)*S0,K~3H,0.Both salts are dehydrated with difficulty. The sulphochloride, CloH,(CN)*SO2C1, crystallises from benzene in small glistening prisms. To judge from the result of a preliminary experiment with bromine, it is probable t'hat the cyanosnlphonic acid now described is a heteroriucleal com- pound. 44 30. Addendum to Paper entitled “An Explanation of the Laws which govern Substitution in the case of Benzenoid Compounds.” By Henry E. Armstrong. In preparing the paper here referred to, having in mind the fact that the “ basic ” powers of nitrogen become enhanced by introduction of hydrocarbon radicles in place of hydrogen, it appeared to me not improbable that the behaviour of a compound such as dimethylaniline, for example, would not in all cases be strictly in accordance with the para-ortho-law ; but I did not find any such departure recorded in the indexed literature. I have since become aware, however, that I failed to remember two recent papers, the one by A.Groll (Ber., 1886, 198), the other by E. Nolting (ibid., 545). According to Groll, dimethylaniline sulphato yields on nitration at a temperat me not exceeding 5”, besides the paranitro-derivative, no less than 80-85 per cent. of metanitrodimethylaniline ; diethylaniline behaves simi-larly. Nolting not only confirms these statements, but adds that ethylaniline sulphate also yields a large proportion of mota-derivative ; and that on nitrating ethylparatoluidine sulphate, the nzetanitro- derivative, NHEt : NO, : Me = 1: 3 :4, is exclusively formed; whereas, according to Wurster, the bromodimethylaniline obtained by brominating dimethylaniline dissolved in acetic acid is the para- modification ; and, according to Beilstein and Kuhlberg, paracetoluide yields only the orthonitro-derivative, NHAc : NO, : CH, = 1: 2 : 4.These facts appear to materially strengthen my argument that the meta-derivatives are formed from an additive compound, resulting from the association of the reacting molecule with the radicle R‘ of the parent compound. In further support of the argument underlying my paper (Trans., 1887, 258) that the formation of an additive compound precedes that of the substitution derivative, I may take the opportunity to point out that on this assumption it is not difficult to understand that, for example, two hydrogen-atoms in ethylic acetoacetate, Ac*CH,*COO Et, are not both immediately displaceable by sodium ; probably an addi- tive compound with sodium ethoxide is first formed, which becomes resolved into alcohol and acetosodacetate, Ac*CH,*CO,Et + NaOEt = Ac*CH,*(CO,Et-ONaEt)= Ac*CHKa*CO,Et+ EtOH; owing to the influence which the sodium exercises on the contiguous CO,Et group, this is no longer capable of uniting with sodium ethoxide, and only recovers the power of so doing on displacement of the sodium by a hydrocarbon radicle.31. “ The Transformation of Citric Acid int!o Pyridine-derivatives, aud on the Constitution of Pyridine.” By S.Ruhemann, Ph.D., Jac ksonian Demonstrator in the University of Cambridge. 45 Hofmann and Behrmann have shown ihat citramide is converted by heating with sulphuric acid into citrazinic acid, the dihydroxy- pyridinecarboxylic acid in which both hydroxyls are in ortho-posi- tions to the nitrogen-atom, the carboxyl being in the para-position. The author finds that the formation of the pyridine-derivative takes place even at ordinary temperatures if ethylic aceto-citrate be mixed with strong aqueous ammonia and the mixture allowed to stand several days ; dilute chlorhydric acid then precipitates citrazinamide, The production of a pyridine-derivative in this manner is a strong argu- ment, he thinks, in favour of Riedel's contention that the nitrogen-atom in pyridine is in connexion with the carbon-atom which relatively to it is in the para-position ; and in further support of this view he states that no condensation takes place if methylamine be substituted for ammonia, there being in this case no available hydrogen-atom asso- ciated with the nitrogen-atom to separate with the hydroxyl and thus permit of the union of the nitrogen-atom with the para-carbon-atom. Incidentally it is mentioned as an indication of the mobility of the acetyl-gronp that if ethylic aceto-citrate be treated with phenyl hydrazine, the acetyl-derivative of the latter is formed ; ethylic aceto- malate and diacetot,artrate behave similarly.32. " Silver containing Bismuth." By William Gowland, A.R.S.M., Chemist and Assayer of the Imperial Mint, Osaka, Japan, and Yoshimasa Koga, Assistant Assayer.An account is given of assays and metallurgical experiments made with the object of determining the effects produced by the presence of small quantities of bismuth on the ductility of silver, and on the uniformity of composition of silver bullion when in ingots of the form and size ordinarily met with in commerce. It is found: a. That when silver is obtained from copper containing bismuth by the liyua- tion process with subsequent cupellation of the argentif erous lead, it contains part of the bismuth which was present in the copper; p. That this silver is brittle even when containing bismuth in but small amounts ; y. That ingots of such silver are not uniform in composi- tion throughout their mass, the parts which have solidified last being richer in silver than the others; and 6.That when coinage bars of 900" millesimal fineness are prepared from it, they cannot be rolled without special treatment, and even then are hard and unsuitable for mint age. 46 ADDITIONS TO THE LIBRARY. I. Donations. Life and Works of Thomas Graham : by R. Angus Smith : edited by J. J. Coleman : Glasgow, 1884: from the Editor. Natural Magick : by John Baptista Porta: London, 1658. L’Art du Fabricant d’Etoffes en Laines: L’Art de preparer et d’imprimer les gtoffes en Laines : L’Art du Fabricant de Velours de Coton : par R. de la Platiere : Paris, 1780. Prolusiones. ad Chemiam Saeculi decimi noni : by J.J. Winter1 : Bud%, 1800 : from the Royal Society. New and Original Theories of the Great Physical Forces : by H. R. Rogers : London, 1878 : from the Royal Society. Die Milchpruf ungs-methoden und die Controle der Milch in Stadten : von P. Vieth: Bremen, 1879. Easy Methods for the Examination of Milk: by P. Vieth :London, 1887: from the Author. Geological and Natural History Survey of Canada : Annual Report and Maps: Vol. I (New Series), 1885 : Montreal, 1886 : from the Director. New York Experimental Station : 5th Annual Report, 1886 : Elmira, N.Y., 1887 : from the Director, 11. By Purchase. Zeitschrift fur Physikalische Chemie, Stochiometrie und Verwandt-schaftslehre : Herausgegeben von W. Ostwald und J. H. van’t Hoff : Band I, 1887 (continued) : Leipzig. The Anniversary Meeting will take place on March 30th, at 8 P.M. At the next Ordinary Meeting, on April 7th, the following paper will be read:- “ Researches on the Constitution of Azo-s>nd Diazo-derivatives. Diazo-amido-compounds.” Part 11. By R. Meldola, F.R.S., and F. W. Streatfeild.
ISSN:0369-8718
DOI:10.1039/PL8870300039
出版商:RSC
年代:1887
数据来源: RSC
|
|