摘要:

AbstractAs there are no published data on the heats of solution of papermakers' alum [composition approximately Al2(SO4)314H2O] and only one value for the heat of solution of Al2(SO4)3, 18H2O in water, heats of solution at room temperature have been measured in the concentration range up to saturation, and all heat effects were found to be exothermic. The heat of solution per gram of alum is appreciably constant if more than 30 g. water is added. Heats of dilution were also exothermic. The resulting thermal data on solution and dilution were combined to give relative partial specific enthalpies of alum and water at all stable concentrations at 25–30°. A few measurements were made of heats of solution at 65–70°. Thermal effects were again exothermic but of smaller magnitude.By hydrating the alum fully a material almost identical with the normal sulphate, Al2(SO4)3, 16–17H2O, was obtained and its heat of solution at high dilution measured, from which the heat of hydration was calculated. About 50% of the heat of solution of alum is heat of hydration. These data enable all the heats of solution and dilution of alum to be recalculated in terms of Al2(SO4)3, 1

ISSN:0021-8871    

DOI:10.1002/jctb.5010100402

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY

摘要:

AbstractThe addition of oxalic acid, under controlled conditions, to a sulphate leach solution derived from monazite sand produces a thorium oxalate phosphate complex which shows a selective thorium enrichment relative to the concentrations of thorium, phosphate and rare earths in the leach solution. This crude thorium oxalato phosphate is further purified by digestion with a sulphuric acid‐oxalic acid mixture to give a final product with the weight ratios, R2O3/ThO2=<0·3, and PO43‐/ThO2=<

ISSN:0021-8871    

DOI:10.1002/jctb.5010100403

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY

摘要:

AbstractThe corrosion of zinc in circumstances closely simulating those existing in a dry primary cell during storage has been examined with special reference to the effect of ionic impurities. It is shown that, after 12 weeks in ammonium chloride electrolyte solution containing such impurities, the attack on the zinc may be drastically modified. In particular, earlier work is confirmed which suggested that cobalt and nickel are extremely harmful and that mercury exerts a protective influence. No satisfactory explanation of these facts has been found.It is shown that the chemical reactions associated with the corrosion are independent of the added ions. A sequence of reactions is suggested to explain the changes observed in the solution and in the solid corrosion products as corrosion progresses.

ISSN:0021-8871    

DOI:10.1002/jctb.5010100404

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY

摘要:

AbstractThe corrosion of zinc in the presence of mercury in circumstances closely simulating those existing in a dry primary cell during storage has been examined. The work followed closely the lines of that carried out on zinc without mercury (see Part I). The effect was determined of those ions which were shown previously to accelerate the corrosion of zinc in absence of mercury; ions with little effect were used as controls.Mercury greatly reduces the catalytically corrosive action of certain Group VIII metals, particularly cobalt and nickel, but has little effect on the Group V metals. For reasonable protection the entire zinc surface must be amalgamated, either before or at the introduction of the zinc to the electrolyte. It is suggested that the course of corrosion and the subsequent reactions are unaffected by the presence of mercury.

ISSN:0021-8871    

DOI:10.1002/jctb.5010100405

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY

摘要:

AbstractDetails are given of the apparatus used for measuring adsorption isotherms of krypton at −196°, which allowed a rapid and precise measurement of pressure.Surface areas have been calculated, by the B.E.T. method, from the krypton adsorption isotherms on samples of ground quartz and a silica gel. The surface areas of the quartz samples determined by other workers, using B.E.T. nitrogen adsorption and electron microscopy, agreed well with the krypton values, provided that the atomic cross‐sectional area of krypton was taken as 19·5Ǎ2.It was not possible to obtain a ‘standard’ curve from the krypton adsorption isotherms on the non‐porous silicas, but when these isotherms were plotted in logarithmic form, all gave a substantial linear region with the same slope. The logarithmic plot of the isotherm on the silica gel had a different slope; it would seem likely, therefore, that capillary condensation occurred on this sample at low pressure and that the B.E.T. area is

ISSN:0021-8871    

DOI:10.1002/jctb.5010100406

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY

摘要:

AbstractThe preparation and properties of highly purified ethylene glycol dielaidate is described and a study of its union with gaseous oxygen at 55°, 85° and 120° has been made. The reactivity of the ester towards oxygen is compared with that of the normal methyl and propyl esters, and with the behaviour of the correspondingcis‐ester.The main products of gaseous oxidation of ethylene glycol dielaidate have been examined and include 9, 10‐dihydroxystearic acid, oily and resinous ketonic polymers and monobasic and dibasic scission products.A mechanism of autoxidation is advanced offering an explanation for the mode of formation of the several pr

ISSN:0021-8871    

DOI:10.1002/jctb.5010100407

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY

摘要:

AbstractThe phenomenon of almost coincident chromatographic peaks has been examined from a theoretical viewpoint, and a method for their analysis on columns of comparatively low efficiency has been evolved. The technique is illustrated with reference tom‐ andp‐xylene and the practical conditions for such an analysis are given.The theory gives rise also to a method for the identification of isomers which, in certain instances, is considered to be an improvement over the use of conventional retention rat

ISSN:0021-8871    

DOI:10.1002/jctb.5010100408

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY

摘要:

AbstractThe preparation of MgH2by the reaction of hydrogen with magnesium metal in the presence of certain catalysts has been investigated.

ISSN:0021-8871    

DOI:10.1002/jctb.5010100409

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010100401

出版商:John Wiley&Sons, Ltd    

年代:1960

数据来源: WILEY