Equation of state for nonpolar fluid mixtures: Prediction from boiling point constants

Our previous corresponding-states correlation for the second virial coefficient of nonpolar fluids, based on the normal boiling point parameters, has been employed to predict the equation of state of nonpolar fluid mixtures. The analytical equation of state is that of Ihm, Song, and Mason, which requires three temperature-dependent parameters, i.e., the second virial coefficient, a scaling constant for softness of repulsive forces, and a van der Waals covolume. In the previous work, we showed that the temperature-dependent parameters could be calculated by knowing the boiling point constants. In this work, it is shown that using a simple geometric mean for the boiling point temperature and an arithmetic mean for the liquid density at the normal boiling point is sufficient to determine the temperature-dependent parameters for mixtures. The equation of state has been utilized to calculate the liquid density of several nonpolar fluid mixtures. The agreement with experiment is good.