Specific ionic interactions and solubility activity product of caesium perrhenate at 298.10 K

Abstract

The solubilities of caesium perrhenate in aqueous CsCl, NaCl, KCl and KReO₄ solutions at 298.10 K are reported. The solubility activity product for CsReO₄ was determined by using extrapolation functions involving two different mean ionic activity coefficient expressions and the results were compared; the total ionic strengths of all the saturated perrhenate solutions were less than 0.1 mol dm^-3. One of these expressions used is that proposed recently by Panckhurst and Macaskill^1,2 which is an extension of Guggenheim's approach,^3,4 specific ionic interactions in aqueous solutions being explicitly taken into account. Its use led to more consistent values for the solubility activity product for CsReO₄ than those obtained with the other expression which does not incorporate specific interaction parameters. Values of specific ionic interaction parameters for caesium, potassium and sodium perrhenates in dilute aqueous mixtures with CsCl, KCl, KReO₄, KI or NaCl are also reported.