ISSN:0021-8871    

DOI:10.1002/jctb.5010170108

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractA comparison is made of the properties of magnesium oxides prepared from basic magnesium carbonates and Indian and Greek rock magnesites. the density increased with burning temperature and the reactivity decreased. the effect of this on the properties of oxychloride cements is shown.Iodine number is shown to be a good index of reactivity and specific surface (air permeability) to indicate the amount of chloride solution needed to make a workable mix with an oxide.

ISSN:0021-8871    

DOI:10.1002/jctb.5010170102

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractThe activity coefficients of the n‐primary, secondary and tertiary aliphatic amines in very dilute aqueous solution were obtained from determinations of partial pressures or from solubility measurements. the activity coefficient of n‐butylamine increased 1.26 times when the ionic strength of the solution was raised from 0 to 0.75, the approximate value for sea water.Free energies of solution, hydration and vaporisation all showed regular increases with the number of carbon atoms in the molecule. the free energy of solution of primary, secondary and tertiary amines increased by 727, 700 and 610 calories respectively and the free energy of hydration by 85, 143 and 52 calories for each carbon atom. Isomeric aliphatic amines showed an increase in total free energy of hydration in the order, primary, secondary, tertiary, indicating that, as with the isomeric alcohols, the free energy of hydration increased as the molecule became more comp

ISSN:0021-8871    

DOI:10.1002/jctb.5010170103

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractThe thermodynamic functions of trioxane have been calculated at various temperatures in the range 0° to 1,000°k. These results have been used in conjunction with previously published data for trioxane and polyoxymethylene to calculate the enthalpy, entropy and free energy changes associated with the polymerisation of trioxan

ISSN:0021-8871    

DOI:10.1002/jctb.5010170104

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractIn an effort to throw more light on the evaporation and condensation of alkali‐salts metal in high‐temperature furnaces, measurements have been made of the rate of evaporation of captive potassium sulphate droplets at temperatures up to 1500°. Observations on the evaporation rate in nitrogen and in oxidising atmospheres are consistent with the view that, in those conditions, the rate is controlled by the well‐known laws relating to the diffusion process. In the presence of hydrogen or carbon monoxide, the rate of loss of weight is very much increased because the potassium sulphate is then reduced on the surface of the droplet and the reduction products are much more volatile. the rate of weight‐loss then depends on a balance of the transport of the reducing gases to the surface and the diffusion of the reduction products from the

ISSN:0021-8871    

DOI:10.1002/jctb.5010170105

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractThe thermal decomposition of ammonium nitrate in a fused equimolar mixture of sodium and potassium nitrates has been studied. It is shown that the reaction is first order with respect to ammonium ions. the rate of decomposition is increased by cations of a highly polarising nature, whereas anions, such as sulphates, phosphates and fluorides, which act as bases in the system, decrease the rate of decomposition. the observations are in accord with an ionic mechanism for the decomposition of ammonium nitrate, involving the reaction of ammonia with the nitronium ion.

ISSN:0021-8871    

DOI:10.1002/jctb.5010170106

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY

摘要:

AbstractA procedure is described for determining calcium sulphate hydrates by thermogravimetry. the carbonate content, if desired, can also be determined simultaneously. the method has been applied to gypsum plasters and minerals, and has also proved useful in determining the degree of hydration of set gypsum plasters.

ISSN:0021-8871    

DOI:10.1002/jctb.5010170107

出版商:John Wiley&Sons, Ltd    

年代:1967

数据来源: WILEY