Pitzer ion interaction parameters of single aqueous electrolytes at 25°C

The ion interaction parameters (Pitzer parameters), beta((0)), beta((1)), and C-phi for 52 single 1-1 electrolytes in aqueous solutions have been obtained from experimental data in the literature on the thermodynamic properties at 25degreesC using Pitzer's equations. Out of these 52 electrolytes investigated, the ion interaction parameters for nine of them have been reported earlier, but those analyses were limited to only the low concentration region. The present evaluations, however, include the higher concentration data for these systems. The calculated activity coefficients of lithium methanesulfonate, sodium methanesulfonate, potassium methanesulfonate, p-toluenesulfonic acid, 2,5-dimethylbenzenesulfonic acid, sodium formate, sodium acetate, sodium propionate, and ammonium bromide from this analysis and those from earlier evaluations are compared to the available experimental data. The comparisons show better agreement with experimental data when we use the present set of parameters evaluated with data extending to higher concentrations than those reported earlier. In general, the parameters obtained in this study reproduce quite satisfactorily the experimental thermodynamic properties of the electrolytes studied over the entire concentration range. The implications of these parameters are also discussed in terms of interionic forces.