Solvation of ions. XXXI. Partial molal volumes of sodium, silver(I) and copper(I) ions in acetonitrile/water mixtures

Abstract

The partial molal volumes of Na⁺, Ag⁺, Cu⁺, Ph₄As⁺, BPh₄^-, Cl^- and NO₃^- are reported for transfer from water to various acetonitrile/water (MeCN/H₂O) mixtures by using the tatb assumption that ΔV_t(Ph₄As⁺) = ΔV_t(BPh₄^-). The results, which show a complex dependence of ionic partial molal volumes on MeCN/H₂O solvent composition, are discussed in terms of ion-solvent and solvent-solvent interactions. This study complements earlier work on the energetics of transfer (tatb assumption) of these ions from water to aqueous acetonitrile solutions.