Electrochemical cells with CaO-doped thoria and CaF2 as solid electrolytes were used to determine the standard Gibbs energies of formation of barium tungstates in the range 1000 to 1400 K. Concordance of the results from cells with different combinations of electrodes confirms the reliability of the results. Enthalpies of formation and entropies of Ba3WO6, Ba2WO5, and BaWO4 have been calculated at elevated temperatures and at 298.15 K. A comparison of the results with literature data for MeO+WO3 (MeBa, Sr) is presented. The experimental results confirm the predicted order of formation of tungstates from MeO and WO3 in the systems studied. © 1979.
