Estimations of activity coefficients of constituent ions in aqueous electrolyte solutions with the two-ionic-parameter approach

The electrolyte-specific solvation parameter regarding the ionic solvation, and approaching parameter regarding the closest distance of approach between ions, in a electrolyte solution were defined by Lin and Lee [Fluid Phase Equil. 205 (2003) 69-83]. In this study, these two electrolyte-specific parameters of individual ions were correlated with the activity coefficients of ions in different aqueous single-electrolyte solutions from literature. With these two parameters and the two-ionic-parameter approach of Lin and Lee, the individual activity coefficients of the ions in the solutions of fourteen 1:1 type, two 1:2 type, and six 2:1 type electrolytes were calculated and compared to the literature values. Also the comparisons of the predicted and literature osmotic coefficients of aqueous multi-electrolyte solutions were reported. The results showed the estimated values fairly agree to the literature data.