Mean activity coefficient of electrolyte solutions

The mean activity coefficient of electrolyte solutions, [gamma], specifically, the case [gamma] is less than or equal to 1, is analyzed. A model of electrolyte solution based on a psuedolattice approach is presented to compute [gamma] without using fitting parameters, where the (upper)concentration is present at which the electrolyte solution shows [gamma] is equal to 1 (molality scale).