Aqueous solutions of single electrolytes: a correlation based on ionic hydration

Abstract

The concept of hydration is used for evolving a new representation for the excess free energy of aqueous single-electrolyte solutions. The approach used is based on the selection of lithium chloride as a reference electrolyte. Simple equations have been derived for calculating γ± and Ø which are valid over the entire concentration range. These equations involve only two empirical constants for each eletrolyte which are related to the hydration number and the energy of hydration. These equations have been tested with experimental data for 150 electrolytes of different charge types over wide concentration ranges, and have been shown to have a good accuracy.