Thermodynamics of the Sr2+-H+ and Cs+-H+ exchange on cerium(IV) and tin(IV) antimonates

The equilibrium exchange of Sr²⁺ and Cs⁺ ions with the hydrogen forms of cerium(IV) antimonate (CeSb) and tin(IV) antimonate (SnSb) have been studied at 25, 45 and 60°C. The exchange isotherms have been measured for both forward and reverse reactions, at a solution ionic strength or 0.1, by the bath technique. Tin(IV) antimonate has a pronounced selectivity for Sr²⁺ and Cs⁺ in acid medium compared with CeSb. On the basis of the exchange isotherms, various thermodynamic parameters have been calculated and some predictions made for the exchange process taking place in the materials.