Thermodynamic properties of thulium and ytterbium in molten caesium chloride

This work presents the results of a study of the Tm3+/Tm2+ and Yb3+/Yb2+ couple redox potentials vs. Cl−/Cl2 reference electrode at the temperature range (973 to 1123) K in molten CsCl by direct potentiometric method. Initial concentrations of TmCl3 and YbCl3 in solvents did not exceed 5.0 mol%. Basic thermodynamic properties of the reactions TmCl2(l) + 1/2 Cl2(g) ⇔ TmCl3(l) and YbCl2(l) + 1/2 Cl2(g) ⇔ YbCl3(l) were calculated using the temperature dependencies of apparent standard potentials of the couples ETm3+/Tm2+∗ and EYb3+/Yb2+∗.