Volumetric effects due to ion-solvent interaction in aqueous electrolyte solutions

Abstract

The apparent volume of a series of chlorides dissolved in water-including hydrochloric acid and chlorides of divalent cations-is calculated from available data on the density of the aqueous solutions. The concentration dependence of the volume of the electrolytes illustrates the long range electrostriction of water by the ions. The volume of the cations, at infinite dilution, reveals that the electrostriction observed, is composed of two opposite volume effects. The experimental data supports the view that bulky, "icelike" water structures predominate near the surface of a small ion, and dense structures, less organized than bulk water, are present at a distance from the ionic center. © 1985 Carlsberg Laboratory.