Solvent structure. III. The dependence of partial molal volumes on internal pressure and solvent compressibility

Abstract

Partial molal volumes, Vº, at 25ºC were measured for sucrose, ascorbic acid and aspirin in the solvents water, formamide, N,N-dimethylformamide and methanol. The dependence of Vº on solvent compressibility enabled an estimate to be made of the intrinsic volumes, V_int, of the dissolved non-electrolytes. Effective pressures, P_e, in aqueous electrolyte solutions were calculated from previously determined internal pressure data. Substitution of P_e into the Tait-Gibson equation yielded values of V^e, the volume contraction of water due to electrostriction, which agree well with values obtained by other methods.