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(C6H14O6)–H2O, KCl–glycine(NH2CH2COOH)–H2O, KCl–mannitol–H2O, and NaBr–mannitol–H2O at 298.15 K. Densities of the binary systems KCl–H2O, NaBr–H2O, glycine–H2O and conductivities of the binary system NaBr–H2O 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.