Chain-of-rotators equation of state



An equation of state is obtained to describe the fluid state from the supercritical gas to subcritical vapor and liquid for small and large molecules of organic and inorganic substances. The perturbation theory of the fluid state is extended to include rotational contribution of molecular motion in addition to translational and the attractive force contributions. Three equation constants describe a substance and values are presented for 22 substances. Application is made to mixtures with emphasis on their phase equilibria.