Second virial coefficients of polar gases for a four‐parameter model

Abstract

AbstractThe second virial coefficients of polar gases have been studied for a potential function consisting of the Kihara spherical core potential combined with a preaveraged dipole‐dipole interaction term. The molecular parameters ϵ/κ, ρo, a*, and y of this potential function were determined for ten substances by a nonlinear least squares analysis of experimental second virial coefficients. These molecular parameters were related to the critical constants, acentric factors, and fourth parameters of the substances. The resulting equations reproduced the second virial coefficients to within the accuracy of the data. Comparisons with experimental data for substances not included in the development of the relationships indicated that good agreement can be obtained for polar fluids by the method of this study.