The change in the standard Gibbs energy ΔG0 in the formation of double selenates K2MII(SCo4)2·x H2O (MII = Mn, Co, Ni, Cu, Zn; x = 6 or 2)

Abstract

The heterogeneous K2SeO4-MIISeO4-H2O system (MII = Mn, Co, Ni, Cu, Zn) at 298 K was studied using the Filippov eutonic method, yielding values for the change in the standard Gibbs energy ΔG0 for the formation of double selenates in the range 16.2-30.3 kJ/mol. It follows from the ΔG0 values that, in systems without strong interactions in the liquid phase, the formation of poorly soluble double selenates from readily soluble selenates is energetically most favourable.