Simple electrolytes in the mean spherical approximation. III. A workable model for aqueous solutions

Some improvements in the primitive model of electrolyte solutions are discussed within the framework of the mean spherical approximation. Excellent agreement has been found between experimental and calculated osmotic and activity coefficients of 16 alkali halides in H2O at 25 °C, whenever a density dependent hard core ionic diameter is combined with an adjustable but not density dependent dielectric constant. Promising agreement is also found when Pauling crystallographic radii are used for the ions.