GIBBS ENERGIES OF SOLVATION AND SOLVENT TRANSPORT OF SOME SILVER(I) SALTS IN WATER PLUS N-METHYL-2-PYRROLIDINONE AT 30-DEGREES-C

The preferential solvation of the silver salts silver(I) bromate, ioda te, sulfate, and oxalate in the binary solvent mixtures of water and N -methyl-2-pyrrolidinone has been studied by solubility and solvent tra nsport number measurements. The Gibbs transfer energies of the salts f rom water to water + N-methyl-2-pyrrolidinone mixtures, calculated fro m solubility data, were split into their ionic values by using the tra nsfer energies of silver ion determined on the basis of the negligible liquid junction potential method. These data have also been compared with those obtained on the basis of the tetraphenylarsonium tetrapheny lborate method. Solvent transport numbers (Delta') of N-methyl-2-pyrro lidinone were determined for all the salts by employing a concentratio n cell with transference as suggested by Wagner. The results have been interpreted in terms of heteroselective solvation of all the salts, w ith silver ion being selectively solvated by N-methyl-2-pyrrolidinone and anions by water.