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Abstracts of the Proceedings of the Chemical Society, Vol. 4, No. 50 |
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Proceedings of the Chemical Society, London,
Volume 4,
Issue 50,
1888,
Page 35-40
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摘要:
ABSTRACTS OF THE PROCEEDINGS OF TEE CHEMICAL SOCIETY. No. 50. Session 1887-88. March 15th, 1888. Mr. William Crookes, F.R.S., President, in the Chair. Messrs. Charles Francis Totvnsend, John Frederick Hayes and D. A. Nagel were formally admitted Fellows of the Society. Certificates were read for the first time in favour of Messrs. Ludwig Cla‘isen, 6, Sopheinstrasse, Miinchen ; William Henry Dodd, 8, Kempson Road, Fulham, S.W. ; John Gill, Gwealhellis, Helston, Cornwall ; Frederick Preston de Jong, South Shore, Blackpool ; Thomas Enraght Lindsay, B.A., Royal Medical College, Epsom ; John George Taylor, 12, Ernest Street, Jari-ow-on-Tyne ; James Woodward, The Laboratory, Somerset House, W.C. The following mere duly elected Fellows of the Society :-Messrs.Alfred Chiddy, Thomas Ashcroft Elwood, Harold Nicolai Faber, James H. Gardner, James Hart, C. Millard King, Vivian Byam Leaes, Charles E. Munroe, Frederick G. Ruddock, H. Belcher Thornton, Thomas Edward Towerson, Herbert Trewby, Edward Arthur Wates. The following Papers were read :-22. “The Nature of Solutions as elucidated by the heat evolved on their dilution, Part I. Calcium Chloride.” By S. U. Pickering. The data afforded by the experiments of Berthelot and Thomsen being insufficient to determine the nature of the action which takes place 011 dilnting aqueous solutions, the author has undertaken an elaborate examination of’the question, selee ting calcium chloride and nitrate as subjects of study. A new form of mixing calorimeter has been devised, consisting of 36 an oval platinum beaker, divided into two compartments by means of foldiiig doors ; t'his apparatus secures the identity of the tempera- tures of the two liquids before mixing, and obviates a dependence on the accurate comparison of two thermometers.The heat capacity of the solutions was determined by means of two equal resistance coils through which the same current flowed and which heated simul- taneously a known weight of water and of the solution under exami- nation. Experiments with the weaker solutions were conducted in the mixing calorimeter ; the stronger solutions were treated like solids, the heat OP their dissolution in a large quantity of water being determined. The strongest solutions dealt with were supersaturated, containing only 5.7 H,O ; the weakest one contained 1400 H,O, or 0.4 per cent.CaCl,. Various methods of graphic represent'ation were examined, but the only one which led to satisfactory results was the plotting of the heat of dissolution (in an infinite amount of water) of 100 grams of solu- tions of various strengths against the percentage composition of these solutions. The results form a curve of great regularity, but this reguIarity is only apparent ; on differentiation a series of independent curves are obtained, each of which on further differentiation gives a straight line. (The lines are straight within experiment,al en-oi-, but they all exhibit an inclination towards a curved form, which suggests the possibility of the action being even more complicated than is here shown.) Neither these straight; lines nor the first differential curves meet at the points of change when produced.A second differentiation being necessary to reduce the original curve to straight lines, it follows that the action is represented by the equation : Heat of disso-lution = A + ~lp+ /3p2 + nip3, p being the percentage composition, and the other letters constants. Owing to the multiplicity of the breaks and the smallness in the percentage difference corresponding to each additional H,O, the case is one of extreme difficulty, and the exact posit'ion of the breaks is in some instances a matter of uncertainty. To obtain confirmatory evidence the densities of the various solutions were examined; the curve by which they are expressed split up on differentiation into a series of straight lines, as in the cases examined by MendelBef, and the points at which the breaks occur in the curve correspond in every case with those occurring in the heat curve, and, moreover, corre-sponded as accurately as can be expected with definite molecular pro-portions of water.The breaks are as follows :- In heat curve. In density curve. Mean. Composition. 50.84 p.c. CaClz -p. c. CaC12 50 -84p. c. CaCl,,tiH,O 50.66 p. C. CaC1,.1 45'73 ,, 46.62 ), 46-18 ), CaCl,,'TH,O = 46.81 ,, '43.46 ), 43'10 ,, 43-28 ,) CaC12,8H20 = 43.51 ,, 38-52 ,, 38'52 ,, 38.52 ,) CaCI,,10H20 = 38-12 ,, 32-70 ,, 31.8 ), 32-25 ,, CaClz713H20 = 32.15 ,, 26.35 ,, 25.85 ,, 24.10 ,) CaC12,18H,O = 25'50 ,, 17'52 ,, 18.75 ), 18 '13 ,, C1~C1,,28H20 = 18.04 ,, 6-51 ,, 7-40 ), 6.95 ,, CsC1,,90H20 = 6-41 ,, 0.42 ,, 0-49 ,, 0.45 , Cs~C12,1400H,O= 0'44 ,) It having been already shown before this Society that the variation in electrical conductivity and the density of sulphuric acid on diluting with water unanimously prove the existence of certain hydrates in solution, as the results of the study of the densities and the thermal changes are shown to be equally unanimous in the case of calcium chloride solutions, the author is of opinion that there can therefore no longer be any reasonable doubt but that solutions do in reality consist of such hydrates, and holds that any theory of the nature of solutions which ignores their existence must be rejected absolutely and for ever.D~SCUSSION. Dr. ARMSTRONGsaid that although personally he was prepared to agree with Mr. Pickering in his conclusions, he thought that probably very many chemists would hesitate to accept MendeleBf's explanation until evidence of the existence of definite hydrates in solution had been obtained by discussing the dependence of a greater variety of properties on composition : the fact that the same results were arrived at by discussing heats of dissolution and densities in the case of' calcium chloride was therefore a most valuable addition to our know- ledge. Mr. Pickering had incidentally raised the question whether the curves actually met at points corresponding to definite hydrates- the observations hitherto made were not sufEciently numerous to determine this, but judging from the results arrived at by Mr.Crompton in discussing electricai conductivity values, they probably did not ; it was necessary, in fact, to prolong the curves in order to determine the points of intersection. The curves began to change direction at some distance on nihher side of the points corresponding to particular hydrates : this probably was due to the fact that in a given solution, even before sufficient or more water is present to form a hydrate A, a varying quantity of a hydrate B richer in water, or of a hydrate C containing less water, according to circumstances, is formed. If this be the case, it is to be expected that if sufficiently 38 numerous observations are made at different temperatures, it will be possible by MendeleBf’s method to determine not only the nature of the hydrates present, but also within certain limits the extent; to which dissociation has set in.Mr. CROMPTONpointed out that Professor Pickering’s results again showed the necessity in this and kindred problems, of no longey assuming a curve to be continuous simply on account of its presenting a smooth and ragular appearance: on analytical treatment such an apparently continuous curve might break up and prove to be discon- tinuous and made up of a series of curves, as in the present case. The apparent regularity of Thornsen’s heat of dissolution curves was largely owing to the method of representation adopted, and want of a sufficient number o€ observations in most cases prevented an analysis of his results.The method hitherto pursued of merely measuring the heat evolved at points where breaks in tlhe curve might be expected to occur, was also hardly calculated to lead to the detection of such breaks, as these would best be discovered when the directions of the intermediate curves had been determined. 23. ‘‘ The Action of Thiocpanates on Aldehyde Ammonias.” By A. E. Dixon, M.D. The author describes the products of the interaction of benzylthio-carbimide with aldehyde-ammonia and valeraldehyde-ammonia; of ethyl-, allyl-, phenyl- and orthotolylthiocarbimide with aldehyde-ammonia ; and of phenylthiocarbimide with valeraldehyde-ammonia. They apparently may all be regarded as derivatives of the compound which Nencki obtained from thiocarbamide and aldehyde-ammonia ; this the author represents as a closed chain compound of the formula CS<~~:~~[~~~>N€€.It is pointedout that R.Schiff, by operat- ing in practically the same way, obtained compounds differing in composition from those prepared by the author ; and it is suggested that Schiff may not have prepared the substances in a sufficiently pure state for analysis. 24. “ Carboxy-derivatives of Quinone.” By J. U. Nef. The author originally undertook the preparation of quinonetetra-carboxylic acid, C6(02) ( C02H)4,in order to compare it with croconic acid, which has the same percentage composition, the constitution of which was undetermined at the time when the experiments were commenced ; the results are entirely confirmatory of the conclusion that croconic acid is not ;i benzene-derivative.39 All attempts to oxidise dnrenequinone, C,(O,) (CH,),, proving un- was converted into dini- successful, durylic acid, c6~~(c~3)3~coo~, trodurylic acid, from which by oxidation with pernianganate the tetracarboxy-acid was prepared ; and ultimately this was converted into quinonetetracarbosylic acid. The preparation both of these compounds and of a variety of inte~mediate products and derivatives and their properties are fully described in the paper ; a portion of the results have already been published in the AnnixZen (237,I; c,f: Chem.Xoc. Abs., 1887, 255). Ethylic diamidote tracarboxylate, from which the quiiione cai-boxyl- ate was obtained by oxidation with nitric acid, closely resembles the allied diamidoterephthalate studied by v. Baeyer ; on reduction it is converted into a hexahydrobenzene-derivative-ethylic paradiketo-CH(CO,Et)*CH(C0,Et)>co. hexamethylenetetracarboxylat;e, "<CH( CO,Et)*CH(CO,Et) Ethylic quinonetetracarboxylate has a yellow colour, but is odourless ; it sublimes readily without decomposing, and is scarcely acted on even by prolonged heating with concentrated nitric acid. Ethylic quinohetracarboxylate, C,(OH),( CO,Et),, prepared by reducing the quinone with zinc-dust and acetic acid, is a very remarkable sub- stance : on further reduction it, is converted into the paradiketohexa- methylenecarboxylate, which most closely resembles Herrmann's ethylic succinosuccinate ; it exists apparently in three distinct modifi- cations, only two of which, however, have been studied-the one modification is green and crystallises in needles; the other is pale yellow and crystallises in plates ; after fusion and cooling, t'lie former appears dark yellow, the latter bright yellow.If either modification be separately dissolved in carbon bisulphide, a solution is obtained from which the two substances crystallise out together ; the solution has the same colour and the same absorption-spectrum which eve^ modification be dissolved. In the paper the author calls attention to a number of similar cases of dimorphism.Quinoltetracarboxylic acid has a pale-yellow colour, and yields yellowish mctallic salts which exhibit a characteristic green fluorescence ; it is not converted into quinonetetracarboxylic acid by oxidising agents : a similarly re- markable resistance to conversion into the corresponding quinone- derivative has been observed by the author in the case of quinolcarb-oxylic acid. 25. " The Action of Acetone pn Ammonium Salts of Fatty Acids in presence of Dehydrating Agents." By S. Ruhemann and D. J. Carnegie. As chief product of the interaction of acetone and amnioninm 40 acetate in presence of phosphoric anhydride, the authors have ob- tained a base of the formula C,H15N,which they find is identical with the dehydrotriacetonamine discovered.by Heintz. On treating the compound C,H,,N with bleaching-powder solution, it gave an Un-stable chlorinated derivative ; on submitting this to the action of alcoholic potash a liquid (b. p. 78-79') was obtained which the authors regard as a new isopropyl alcohol hydrate of the formula C,H,O.OH,. The same substance was produced on substituting formate and butyrate for the acetate : hence it follo~s that only the ammonia of the salt is concerned in the formation of the base. 26. " A Method of Estimating Nitrites either alone or in presence of Nitrates and Chlorides." By T. Cuthbert Day. The method consists in saturating the solution containing the nitrite with solid ammonium chloride, boiling the mixture in a suitable apparatus, after removal of the air by carbonic anhydride, and collecting and measui-ing the nitrogen evolved ; interaction takes place according to the equation N02K + NH,Cl = KC1 + 20H, + NP,hence the quantity of nitrite present in the substance under analjsis is calculated froni half the volume of nitrogen obtained. The Anniversrlay Meeting mill take place on Wednesda,y, March 28th, at 8 P.M. The President will deliver an Address on Elements aid Meta-elements. HARRISOX AND SOTSS, PRINTEltS Ili 0XI)IIYART TO HER MAJESTY, ST YARTIN'S LANE.
ISSN:0369-8718
DOI:10.1039/PL8880400035
出版商:RSC
年代:1888
数据来源: RSC
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