Thermodynamics of 1 : 1 electrolyte solutions at 298.15 K in aqua-DMF mixed solvent system: excess volume of mixing

Abstract

Excess volumes of mixing for six possible binary combinations of solutions of NaCl, KCl, NaBr, and KBr have been determined at constant ionic strength of 1.000 and 2.000 mol kg−1 at 298.15 K using dilatometer in water + N,N-dimethylformamide mixed solvent system. Pitzer's virial coefficient theory has been utilized to obtain binary and triplet interaction parameters i.e., θ V and ψ V . Data do not support Young's cross square rule (CSR). The deviation from CSR is considered to arise from significant contributions of triplet interactions and preferential solvation of the ions and ion-clusters in the mixed solvent system.