Model for the Conductivity of Ionic Mixtures within the Mean Spherical Approximation. 1. Three Simple Ionic Species

Abstract

We recently obtained simple expressions for the concentration dependence of the conductance of an electrolyte with two simple species and a mixture with three ionic species. The Fuoss−Onsager continuity equations were solved using equilibrium pair distribution functions. Various equilibrium pair correlation functions can be used for this purpose; those of the MSA theory (mean spherical approximation) yield explicit expressions for the variation of conductivity with concentration, which are in good agreement with the experimental data. Aqueous solutions of NaCl, KCl, and MgCl 2 and mixtures of NaCl/KCl and NaCl/MgCl 2 were examined at concentrations up to 1 equiv of solute per liter.