The hydration entropies of ions and their effects on the structure of water

Abstract

The conventional entropies of hydration are interpreted in terms of contributions from conversion to the absolute scale, compression from the gas to the solution standard states, long-range electrostatic interactions, immobilization of the solvent near the ion, and water-structural effects. A simple but effective method for the estimation of the entropy of solvent immobilization is presented. Correlations between the entropy of hydration of ions and various measures of the effects of ions on the structure of water, applied in the past mainly ot monoatomic ions, are extended to polyatomic ones.