Analysis of Activity Coefficients in Aqueous Solutions of Alkali Metal Bromides Based on Dielectric Properties

Abstract

Extended Debye–Hückel (EDH) theory was used to calculate activity coefficients in aqueous solutions of alkali-metal bromides at 298 K from experimentally determined values of their static permittivities. Calculations with non-optimized model parameters fit the nonmonotonic concentration-dependent trend of the activity coefficients and the cation radius–dependent trend of the activity coefficients. The latter is explained by hydration weakening and ion association strengthening in response to increasing cation radius in the salt series.