Calculation of Pitzer Parameters at High Ionic Strengths

Abstract

A technique is developed for univalent salts that allows calculation of activity coefficients at very high ionic strengths using solubility data. Pitzer parameters for binary solutions are extended to ionic strengths exceeding the salt solubility limits. Pitzer mixing parameters are obtained from solutions with ionic strengths much higher than the usual valid range for the Pitzer method. The method is demonstrated on several salt systems at 25 °C.