Inclusion of the aqueous solution nonideality into the calculation of phase diagrams for systems of water with salts that form complete solid solutions

The extant semiempirical model is modified to describe phase relations in w ater-salt systems with complete solid solutions. Including the ion activity coefficient in aqueous solution into the model enabled avoiding one of emp irical parameters. The new approach is useful in predicting the solubility of mixed crystals in systems that have not been studied experimentally. Mat ching the results of the calculation with the existing experimental evidenc e concerning water-salt systems with solid solutions validates the approach in question for most of the systems hitherto studied.