The influence of solvent nature on thermodynamic properties of the reaction Tm(III)+e¯⇔Tm(II) in molten chlorides

Abstract This work presents the results of a study of the Tm 3+ /Tm 2+ couple redox potentials vs . Cl – /Cl 2 reference electrode at the temperature range (833 to 1073) K in molten equimolar NaCl–KCl and NaCl–2CsCl eutectic by direct potentiometric method. Initial concentrations of TmCl 3 in solvents did not exceed 5.0 mol%. Apparent standard redox potentials of the couples E Tm 3 + / Tm 2 + ∗ were determined in different solvents. Basic thermodynamic properties of the reaction TmCl 2 ( l ) + 1 / 2 Cl 2 ( g ) ⇔ TmCl 3 ( l ) were calculated. The dependence between the apparent standard redox potentials of the couples E Tm 3 + / Tm 2 + ∗ and the ionic potential of the solvents was established.