STATISTICAL-MECHANICAL ANALYTICAL EQUATION OF STATE FOR FLUID MIXTURES

A new analytical equation of state for fluid mixtures is presented, which is both simple and accurate enough to describe the thermodynamic properties of a general fluid mixture over its entire density range. It is derived by statistical-mechanical perturbation theory for hard-sphere mixtures, as a generalization of Song and Mason's equation for pure fluids. Agreement with computer simulations for Lennard-Jones binary mixtures is quite remarkable. The equation of state can be calculated if all the intermolecular potentials are known, but for practical purposes knowledge of just the second virial coefficients is sufficient to determine the whole equation of state. © 1990 Taylor & Francis Ltd.