Thermodynamic Characteristics of Resolvation of Bromide Ions in Water–Dimethyl Sulfoxide Mixtures

Real and chemical thermodynamic characteristics of resolvation of bromide ions in water–dimethyl sulfoxide mixtures and a surface potential of dimethyl sulfoxide are presented and analyzed. The data are obtained by the method of Volta potential differences. The real thermodynamic characteristics of the bromide ion transport are positive (as those of the chloride ion studied earlier). This is due to structural rearrangement of the surface layer at the solution/gas interface when passing from water to water–organic substance mixtures. According to an analysis of the chemical energy of the bromide ion resolvation, anions that are capable of forming hydrogen bonds with proton-donor solvents are weakly solvated in aprotic solvents.