Determination of Standard Gibbs Energy of Formation of Al_2Nd by Solution Calorimetry and Heat Capacity Measurement from Near Absolute Zero Kelvin

摘要

The thermodynamic properties of Al2Nd were investigated by calorimetry. The standard entropy of formation of Al2Nd at 298 K, DELTA S_(298)~o(Al_2Nd), was determined from measuring the heat capacities, C_p, from near absolute zero (2 K) to 300 K by the relaxation method. The standard enthalpy of formation of Al_2Nd at 298 K, DELTA S_(298)~o(Al_2Nd), was determined by solution calorimetry in hydrochloric acid solution. The standard Gibbs energy of formation of Al_2Nd at 298 K, DELTA S_(298)~o(Al_2Nd), was determined from these data. The results were obtained as follows: DELTA S_(298)~o(Al_2Nd)/KJ centre dot mor~(-1) = -10.7 + - 1.2, DELTA S_(298)~o(Al_2Nd)/kJ-mol~(-1) = -105.03 + - 27, and DELTA S_(298)~o(Al_2Nd)/kJ-mol~(-1) = -101.85 + - 27.