R. Kandan

Thermodynamic studies on ThGa2

Abstract The enthalpy of formation of ThGa 2 was determined by high temperature gallium solution calorimetry and precipitation calorimetry. The values thus obtained are −(55.1±4.8) and − (69.6±5.6) kJ g atom −1 with reference to α-thorium and solid gallium at 298.15 and 1100 K, respectively. These are the first calorimetric results for the enthalpy of formation of ThGa 2 . The Gibbs energy of formation of ThGa 2 with reference to α -thorium and liquid gallium was determined by molten salt galvanic cell measurements to be −75.1+0.024T kJ g atom −1 in the temperature range 682–891 K. The partial molar excess Gibbs energy of thorium in liquid gallium in the saturated solution at 787 K was determined to be − (123.3±4.7) kJ g atom −1 . The partial molar enthalpy of solution of thorium in liquid gallium at infinite dilution at 1095 K was determined to be − (178.6±6.8) kJ g atom −1 and partial molar enthalpy of thorium in liquid gallium in the saturated solution at 787 K to be − (164.2±4.7) kJ g atom −1 .