Studying the Iodide Ion Solvation in Water–Dimethyl Sulfoxide Mixtures by the Method of Volta Potential Differences

Abstract

Real and chemical thermodynamic parameters of resolvation of the iodide ion in water–dimethyl sulfoxide mixtures at 298 K are determined by the method of Volta potential differences. The real parameters, as those of chloride and bromide ions earlier studied in similar solvents are positive, which is due to the restructuring of a surface layer at the solution/gas phase interface. An analysis of chemical energies of the iodide ion resolvation shows that anions that are capable of forming hydrogen bonds with proton-donor solvents are weakly solvated in aprotic solvents.