THE THERMOCHEMICAL PROPERTIES OF BACEO3(S) AND SRCEO3(S) FROM T = (5 TO 1500)K

The standard molar enthalpies of formation of BaCeO3(s) and SrCeO3(s) have been derived by combining the standard molar enthalpies of soluti on of the two compounds in (1.00 mol.dm(-3) HCl + 0.10 mol.dm(-3) KI)( aq) obtained from literature, and measurements of auxiliary data. The following values have been derived: Delta(f)H(m) degrees(BaCeO3, s, 29 8.15 K) = -(1690.0 +/- 2.5)kJ.mol(-1) and Delta(f)H(m) degrees{SrCeO3, s, 298.15 K} = -(1687.1 +/- 2.7)kJ.mol(-1). Low-temperature adiabatic heat capacity measurements and high-temperature enthalpy increment me asurements by drop calorimetry have been performed on SrCeO3(s), and t he thermodynamics of formation of the two compounds have been derived at selected temperatures up to T = 1500 K. (C) 1998 Academic Press Lim ited.