Enthalpies of formation of CeNi 2 and CeNi 5 by calorimetry

Abstract

The enthalpies of formation of the intermetallic compounds, CeNi 2 and CeNi 5 at 298.15 K have been determined by high temperature solution calorimetry. The thermal effects of dissolution of nickel, cerium and the intermetallic compounds in liquid aluminum at 1095.15 K were determined as a function of concentration of the solutes from which the respective thermal effects of dissolution at infinite dilution were derived. The enthalpies of formation of the compounds at 298.15 K were computed from these values of thermal effects of dissolution at infinite dilution. The enthalpies of formation of CeNi 2 and CeNi 5, at 298.15 K thus obtained are −115.8 ± 7.3 and −201.9 ± 11.9 kJ mol −1, respectively. The present enthalpy of formation of CeNi 5 is compared with the earlier literature values. In the case of CeNi 2 the study provides the only experimental data for the enthalpy of formation.