Volume 13, Issue 4, 01 April 1945
Index of content:
13(1945); http://dx.doi.org/10.1063/1.1724012View Description Hide Description
Thermal expansions and compressibilities are calculated from equations of state of the Grüneisen form which are derived from a general partition function. The non‐thermal energy and frequency are obtained as functions of volume, the constants in these functions being evaluated from data on the second virial coefficients of gases. Data of state are calculated for three types of thermal energy distributions, the classical, the Einstein, and the Debye. A limitation on the harmonic oscillator approximation is discussed as is the quantal effect in the law of corresponding states.
13(1945); http://dx.doi.org/10.1063/1.1724013View Description Hide Description
A molecular theory of the scattering of light by fluids of isotropic molecules is developed, utilizing recent advances in the statistical mechanics of condensed phases. The results are shown to be the same in first approximation as those of the continuous theory based on fluctuations originally proposed by Smoluchowski and Einstein. Higher approximations of the molecular theory are especially applicable to the study of critical opalescence and fluids consisting of very large molecules.
13(1945); http://dx.doi.org/10.1063/1.1724014View Description Hide Description
The paper discusses potentiometric measurements of hydrogen ion concentration carried out in hydrocarbon oils that have attained high electrical conductivity (a) through oxidation in the laboratory, (b) through deterioration in service, (c) through addition of certain compounds. The e.m.f. data are interpreted by comparing them with those obtained from lauryl sulfonic acid solutions in oil. The results indicate that the hydrogen ion concentration in the three types of oils is too low to account for the total observed electrical conductivity. It is obvious, then, that the predominant mechanism of ion generation is different from the usual acidic dissociation. A bimolecular reaction leading to two organic ions is suggested on the basis of evidence from organic chemistry and a quantitative relation that follows from conductivity data presented in this paper.
13(1945); http://dx.doi.org/10.1063/1.1724015View Description Hide Description
The contribution from freely rotating atoms to the intensity of electron scattering by gaseous molecules is obtained by means of an asymptotic evaluation of an integral, using the saddle point method. It is possible now to estimate the effect of the approximation in using the Debye formula, which is a specialization of the derived series, and, if desired, to obtain a higher degree of accuracy. Two cases are considered numerically.