Conductances and solubilities of uni-univalent electrolytes in 2-cyanopyridine at 30�C

Abstract

Conductance measurements for twenty-five uni-univalent electrolytes in 2-cyanopyridine at 30°C (dielectric constant=93.8) were made over the concentration range of 1.4-100×10−4 mol-dm−3. All conductance data were evaluated by the Lee-Wheaton equation. The results indicate only slight association for most of the salts but Et2H2NBr and Et3HNBr are quite strongly associated while ammonium picrate, AgNO3 and LiClO4 show less, but significant, association. Picric acid was found to be a weak acid in 2-cyanopyridine. Ionic limiting equivalent conductances were evaluated using (i-Pent)3BuNPh4 as a reference electrolyte. Anions appear tobe poorly solvated while cations show some evidence of ion-solvent interaction. Solubilities were determined for eight salts of moderate-to-low solubility in 2-cyanopyridine. Single ion free energies of transfer from water to 2-cyanopyridine were estimated for ions from these salts using the AsPh4NBPh4 approximation. The results indicate that 2-cyanopyridine is not a particularly good solvating medium for most common inorganic salts.