Abstract
The thermodynamic treatment of a fluid in an electrostatic field is applied to the calculation of the partial molar volume of electrolytes in aqueous solutions at infinite dilution. The electrostriction may be interpreted in terms of a general solvation number that accounts for the total solvent—solute interaction. This treatment is further extended to the free energy and entropy of solvation in terms of the same intrinsic radii, giving reasonable agreement with literature data.