Degree of binary association in electrolyte solutions. The roles of the short-range interionic potential and of the friction coefficient

Abstract

The degree of binary association in 1:1 electrolyte solutions has been calculated from the radial distribution functions for concentrations in the range 0.1–1.0 mol dm^–3 at 300 K. These functions were obtained by and Brownian dynamics. Two short-range interionic interaction potentials and three friction coefficients were used. The influence of the Brownian collisions on the degree of association increases with the intensity of the forces. Comparison with experimental data shows that the model corresponds to strongly associated electrolytic solutions. The dynamics of formation show that 95 % of the binary pairs detected by equilibrium methods are stable during a mean lifetime greater than 1.5 × 10^–12 s.