Extension of self-consistent local-composition models for correlation of densities of aqueous electrolyte solutions

Expressions for the excess volume of electrolyte solutions are obtained for the self-consistent local-composition (SCLC) model and the modified SCLC (MSCLC) model. Applicability of obtained equations in the correlation of the densities of aqueous solutions of different kinds of salts (1:1, 2:1, 1:2 and 2:2) at 298 K is examined. It is found that the both original and modified SCLC models are suitable models in representing the published density data for the tested aqueous salt solutions. The results obtained from these models were compared with those obtained from the non-random two liquid (NRTL) and the Pitzer models.