摘要:

AbstractOxygen and hydrogen bromide catalyse the decomposition of 1‐bromo‐2‐methylbutane. The relative proportion of the main reaction products, 3‐bromo‐2‐methylbutane and 2‐bromo‐2‐methylbutane, varies according to whether the decomposition occurs in a sealed tube or under atmospheric pressure. The decomposition of any one sample proceeds rapidly to a certain extent and the

ISSN:0021-8871    

DOI:10.1002/jctb.5010191101

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe results of oxidation of some mono‐aryl aliphatic olefins by chromic acid in aqueous sulphuric acid and by chromic oxide in acetic anhydride are compared and discusse

ISSN:0021-8871    

DOI:10.1002/jctb.5010191102

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractIsoprene was dimerised by lithium naphthalene to linear isoprene dimer, a mixture of 2,6‐dimethyl‐2,6‐octadiene and 2,7‐dimethyl‐2,6‐octadiene, i

ISSN:0021-8871    

DOI:10.1002/jctb.5010191103

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractPhase equilibrium data are presented for thiophen and benzene distributed between n‐heptane and ‘Sulpholane’, dimethyl sulphoxide and dimethyl formamide. They are used to evaluate the possibility of employing distribution between these solvents as a means of separating a mixture of thiophen and be

ISSN:0021-8871    

DOI:10.1002/jctb.5010191104

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractAdsorption–desorption isotherms of water vapour at 30° were determined on preparations of calcium silicate hydrates of different molar ratios of lime/silica before and after free lime and free silica extractions. From these isotherms specific surface areas were measured and total pore structure analysis was evaluated.A surface layer thickness (t) curve for the adsorption of water vapour on calcium silicate hydrates was constructed, based on experimental curves previously published for the number of layers adsorbed on a variety of non‐porous solids with the same heat of adsorption as the calcium silicate hydrates.The existence of both wide pores and micropores was detected in the calcium silicate hydrates. When the samples were free from uncombined lime and silica the micropores were estimated to have an average hydraulic radius of 4–5 Å, whereas the wide pores had an average size of 10 Å. Wide pores up to 200 Å also exist. The pores were predominantly parall

ISSN:0021-8871    

DOI:10.1002/jctb.5010191105

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe kinetics of the isothermal dehydration of zinc and magnesium sulphate heptahydrates were studied bothin vacuoand in the presence of air. Decompositionin vacuofollowed a first‐order mechanism, while that in the presence of air followed an interfacial mechanism obeying the Avrami–Eroféev equation. In the case of zinc sulphate decomposing in air, the fusion of the salt in its water of crystallisation interfered with the observed phenomena. The energy of activation in both cases was calculated to be comparable to the latent heat of vaporisation of water, and it is suggested that this would measure the heat of desorption of water from the surface of the dehydration product. When decomposition was carried outin vacuoat comparatively elevated temperatures, the process changed to an activated diffusion or surface diffusion. Dehydrationin vacuoyielded an amorphous intermediate, as well as final products, whereas dehydration in the presence of air yielded crystalline products. Differential thermal analysis proved the stepwise nature of the dehydration process.The rehydration from the vapour phase was also studied on the dehydration products of both zinc and magnesium sulphate heptahydrates, and it was shown that the rehydration isotherms could be significantly affected by both the extent and the nature of the surface of the dehydration product. The specific surface areas were measured by low temperature adsorption of nitr

ISSN:0021-8871    

DOI:10.1002/jctb.5010191106

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010191107

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010191108

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY