Collect. Czech. Chem. Commun. 1990, 55, 2669-2676

The change in the standard gibbs energy ΔG° during the formation of the double selenates M2Mg(SeO4)2.6 H2O (m = K, NH4, Rb, Cs)

Pavel Vojtíšek and Miroslav Ebert

Department of Inorganic Chemistry, Charles University, 128 40 Prague 2


The energy conditions for the formation of the compounds under the conditions of heterogeneous equilibrium were studied using the Filippov eutonic method, permitting the ΔG° values for the reactions leading to the formation of the above double selenates to be obtained directly. The values obtained, which varied in the range -17.8 to -24.4 kJ mol-1, were correlated with the solubilities of the compounds formed and the selenates M2SeO4. The interaction M2SeO4-MgSeO4 in the liquid phase was also studied.