Heat Capacity and Thermodynamic Properties of Triuranium Silicide from 1 to 1203 K

The heat capacity of triuranium silicide, U3Si, has been measured from 1 to 350 K and its enthalpy determined from 298 to 1160 K. The coefficient γ for the heat capacity contribution of the conduction electrons (γT) is (39.3 ± 0.4) mJ K-2 mol-1. Thermodynamic functions are tabulated at selected temperatures between 1 and 1203 K. At 298.15 K, the values determined for the heat capacity Cp o, the entropy So, the enthalpy {Ho(298.15 K) - Ho(0)}, and the function {Go(298.15 K) - Ho(0)} 298.15K are (107.90 ± 0.43) J K-1 mol-1, (174.02 ± 0.70) J K-1 mol-1, (23297 ± 93) J mol-1, and -(95.88 ± 0.38) J K-1 mol-1, respectively. The standard Gibbs energy of formation ΔGf o(U3Si, c, 298.15 K) = -(105.6 ± 19.2) kJ mol-1 was derived