Heats of mixing of nonelectrolytes

Abstract

The first-order perturbation method is applied to a rapid estimation of heats of mixing of binary liquid mixtures containing molecules with a negligible polarity and approximately spherical symmetry. The calculation is based on the approximate perturbation expansion of the Helmholtz free energy up to first order and requires the knowledge of the radial distribution function of the hard-sphere reference system at the contact point. Generalized relations are used for estimating the molecular parameters. The calculated values are compared with experimental data on six mixtures. Good qualitative agreement was achieved in all cases investigated.