Thermodynamic and Electrical Conductivity Studies on Ion Association of zinc sulphate in N, N-Dimethylformamide –Water mixed solvents

The conductance of zinc sulphate in binary mixtures N, dimethylformamide –water (DMF–H2O) using the organic solvent mass fractions of 10%, 20%, 30% and 40% at different emperatures of (298.15, 303.15, 308.15 and 313.15) K was measured experimentally. The experimental data are already analyzed through the use of Fuoss-Shedlovsky technique. Molar conductance (Λm), limiting molar conductance (Λ0), the ion-pair association constant (KA), as well as the standard thermodynamic parameters for association (ΔGoA, ΔHoA and ΔSoA) were estimated and also discussed. It was observed that adding DMF to mixtures caused the molar conductance values were decreased since the relative permittivity of the solvent decreased while. Clearly strengthening the ion association at higher temperatures is basically the result of a decrease in the permittivity of the solvent. The positive values (ΔH0) show that the association processes are endothermic naturally. Entropy change (ΔS0) values were positive as a result of decrease in solvation of ion-pair compared to that of the free ion. This related to increase in the degree of freedom upon association.