Activity coefficients of electrolytes in binary mixtures calculated using total molal quantities

Activity coefficients in binary mixed electrolytes are expressed in terms of the parameters from total molal quantities. Two versions of the calculations are presented and compared with the methods of Pitzer and Scatchard. For each method interrelations among the various parameters are examined. The system being tested is HCl+CoCl₂+H₂O at 25°C, for which new experimental data at low ionic strengths are included.