Solubility of caesium hexachlororhenate(IV) and hexabromorhenate(IV) in water and in mixed aqueous solvents

Abstract

The enthalpies of solution of caesium hexachlororhenate(IV) and hexabromorhenate(IV) in water have been determined, from the temperature variation of their solubilities, as +88 and +96 kJ mol^–1 respectively. Hence the single-ion enthalpies of hydration of the (gaseous) hexachlororhenate(IV) and hexabromorhenate(IV) anions have been estimated, using the assumption that the single-ion hydration enthalpy of the proton is –1 091 kJ mol^–1, as –845 and –786 kJ mol^–1 respectively. Attempts to correlate the solubility of caesium hexachlororhenate(IV) in mixed aqueous solvents with various empirical solvent parameters are described.