Critical parameters of liquid–vapor equilibrium and its geometric interpretation

Abstract

Expressions are derived for the Gibbs and free energies of a liquid–vapor system. The critical parameters of the liquid are determined, and the character of the relationship between them is found. The temperature dependence of the vaporization heat is found. The analytical expression of the empirical Tait rule is substantiated. General patterns of subcritical and critical equilibria were revealed. A geometric definition of a critical state is proposed, and the existence of two critical states is proven.