The standard Gibbs free energies of formation of Bi2O3 were determined by the EMF technique using the following galvanic cell over the temperature range from (1012 to 1235) K: (-)Pt; Cr2O3; Bi(l); Bi(2)O(3)s; l_jYSZjO2; Ptd__; where YSZ denotes stabilized ZrO2 with 0.085 mass fraction of Y2O3. The standard Gibbs free energy of formation of Bi2O3 was derived from the cell above is described as linear functions of temperature as: D(f)G degrees /(dkJ center dot mol(-1)) = 591 + 511 + 0: 2934T/K +/- 0.492 (1012 <= T/K <= 1098) Bi-liquid; Bi2O3 solid; D(f)G degrees /(dkJ center dot mol(-1)) = 582 + 682 + 0: 2853T/K +/- 0.481 d1098 <= T/K <= 1235) Both phases in liquid: The Delta H-f degrees(298) and S degrees(298) values of alpha-Bi2O3 were calculated to be -567.31 kJ mol(-1)and 148.77 J K-1 mol(-1) using the cp functions presented in the literature and the measured data. The results were compared to the corresponding values of the literature. (C) 2014 Elsevier Ltd. All rights reserved.