Departures from ideality in pure ionic solutions using the mean spherical approximation

Abstract

Departures from ideality in concentrated pure electrolytes are described in the framework of the primitive model of ionic solutions in which the solvent is a dielectric continuum, using the mean spherical approximation (MSA). It is shown that both the activity coefficient of the salt and the osmotic coefficient can be parametrized with the use of two parameters, which are functions of the concentration (ranging from 0 up to the saturation point). The parameters are chosen on the basis of their physical relevance. Results from two different sets are presented. A linear dependence for these parameters is found in the molality range typically between 2 and 6 mol kg^–1.