Preferential solvation of some copper (I), silver (I) and sodium (I) salts in acetonitrile + n-butyronitrile and acetonitrile + N,N-dimethylacetamide mixtures

Viscosities and densities of Bu4NBPh4, Bu4NClO4, Bu4NI, Bu4NBr, Pr4NBr, Et4NI, Et4NBPh4, CuClO4, NaClO4 and NaBPh4 in AN + n-BTN and those of Bu4NBPh4, Bu4NClO4, Bu4NCF3COO, AgCF3COO and CuClO4 in AN + DMA mixtures in the concentration range (3-580) × 10− 4 mol dm− 3 containing 100, 80, 60, 40, 20 and 0 mol% AN have been measured at 298 K. The viscosity data have been analyzed using the Jones-Dole equation in the form: ηηo=1+AC1/2+B⁢C for unassociated and in the formηηo=1+A(C⁢α)12+B(C⁢α)+B′(1−α)Cfor associated electrolytes. The A-coefficients of the Jones-Dole equation are positive and are in reasonably good agreement with the limiting theoretical values (Aη) calculated using Falkenhagen-Vernon equation in some cases and two to three times larger in other cases. The B coefficients of the electrolytes are positive and large in all cases. The ionic B+ and B− coefficients have been evaluated from the B− coefficients of the electrolytes using a method reported by Gill and Sharma. The derived results show a strong preferential solvation of Na+ and Cu+ by n-BTN in AN + n-BTN and that of Ag+ and Cu+ by DMA in AN + DMA mixtures. Br−, I− and ClO4− show weak preferential solvation by the same solvents while CF3COO− shows no preferential solvation in AN +DMA mixtures.