An equation of state for argon

An analytical equation of state was applied to calculate the thermodynamic properties for argon.The equation of state is that of Song and Mason. It is based on a statistical-mechanical perturbationtheory of the hard convex bodies and can be written as fifth-order polynomial in the density. Thereexist three temperature-dependent parameters: the second virial coefficient, an effective molecularvolume, and a scaling factor for the average contact pair distribution function of hard convexbodies. We used Lennard-Jones (۱۲-۶) potential for calculation of temperature-dependentparameters. The equation of state has been applied to calculate thermodynamic properties includingthe vapor pressure curve, the compressibility factor, fugacity coefficient for argon. The agreementwith experiment is good.