A Study of the Molecular Mechanism of Vapour Condensation

Abstract

The condensation coefficient (c. c.) of vapour is investigated on the basis of the transition state theory which is treated in the framework of statistical mechanics of gases and liquids. The theoretical c. c. is reconfirmed to be the ratio of the rotational partition function of a liquid molecule to that of a vapour molecule and is given by thermodynamic quantities available in the literature. The applicability of the theory is clarified through a comparison of molecular flux equation at the vapour-liquid interface with rigorous molecular flux equations based on the molecular gas dynamics of the monoatomic moleoules. It is shown that theoretical predictions of c. c. for water, carbontetrachloride, and glycerol vapour are in good agreement with the experimental results and are significantly smaller than unity.