Preferential Solvation of Acetic Acid in Binary Mixtures of Carbon Tetrachloride–Cyclohexane and Carbon Tetrachloride–1,2-Dichloroethane

摘要

The partition of acetic acid between aqueous solutions and various binary mixtures of carbon tetrachloride + cyclohexane and carbon tetrachloride + 1,2-dichloroethane were carried out at 30.0 °C. The nonlinear dependence of both the monomer partition coefficient and the dimerization constant on the mole fraction composition has been rationalized in terms of preferential solvation of the various solvation sites of the involved species. Two and four polar sites were identified for the monomer and dimer forms, respectively. The solvation preference is controlled by the relative polarities of the binary solvent components, being, in general, higher for the monomer sites compared to the dimer ones. The dimer is almost equally stable in various carbon tetrachloride + 1,2-dichloroethane mixtures, and the variation of dimerization constants with changing binary composition arises mainly from the monomer solvation stabilization.