Properties of Aqueous Mixtures of Pure Salts: Thermodynamics of the Ternary System Water-Potassium Chloride-Barium Chloride at 25 °C

Isopiestic vapor pressure measurements have been made on the system water-potassium chloride-barium chloride. The data have been used to evaluate the activity coefficient of each salt in the presence of the other. Two conditions are considered; in one, the solution is maintained at constant total ionic concentration; in the other, at constant total ionic strength. The excess free energy of mixing is calculated and compared with similar data for the water-hydrochloric acid-barium chloride and water-sodium chloride-barium chloride systems.