A consideration of Pitzer's equations for activity and osmotic coefficients in mixed electrolytes

Abstract

The equations developed by Pitzer and coworkers in order to calculate the activity coefficients of two mixed electrolytes in aqueous solutions are transformed into more simple equations. It is demonstrated that these new equations do not satisfy one of the necessary requirements of thermodynamic arguments, the only exception being when there are two electrolytes that have a common ion and are of the same type.