The Semi-ideal Solution Theory. 4. Applications to the Densities and Electrical Conductivities of Mixed Electrolyte and Nonelectrolyte Solutions

Densities and electrical conductivities were measured for the ternary systems NaCl–mannitol(C 6 H 14 O 6 )–H 2 O, KCl–glycine(NH 2 CH 2 COOH)–H 2 O, KCl–mannitol–H 2 O, and NaBr–mannitol–H 2 O at 298.15 K. Densities of the binary systems KCl–H 2 O, NaBr–H 2 O, glycine–H 2 O and conductivities of the binary system NaBr–H 2 O at 298.15 K were also measured. The measured densities were used to check the predictions of the semi-ideal solution theory. A new approach for predicting the conductivity of ternary electrolyte−nonelectrolyte mixture solutions in terms of the properties of their binary solutions of equal water activity is presented and compared with the measured values. The results show that the semi-ideal solution theory can provide good predictions for the densities and conductivities of the tested ternary electrolyte−nonelectrolyte solutions from the properties of their binary subsystems.