Anion-Exchange Selectivity Trends in Aqueous Acetone Media

Abstract

Equilibrium exchange studies have been performed for Cl–/NO₃–, Br–/NO₃–, I–/NO₃–, I–/NO₃– and CNS–/NO₃– exchanges on Amberlite IRA–400 (NO₃–) in acetone-water media. The corrected selectivity constants were evaluated by graphical integration. Corrected selectivities have been found to vary with the acetone concentration. The free energies of exchange, ΔFº, have also been calculated to show the selectivity differences in mixed acetone-water media. The effect of increasing acetone in the mixed solvent systems on the exchange of anions and selectivity reversal for CNS– ion at higher acetone percentages (v/v) have been explained.