The Entropy of Aqueous Solutes

Abstract

The standard partial molal entropies of monatomic ions and of non-electrolytes in aqueous solution can be represented by the empirical expressions, for monatomic ions:S̄0=(3/2)R lnM+37–270Z/re2,for non−electrolytes:S̄0=Sint+(3/2)R lnM+10–0.22VM.Here Z is the absolute value of the charge on the ion, re is the effective radius of the ion, and VM is the molal volume. These expressions can be interpreted in terms of the smoothed-potential type of partition function for the system.