MEASUREMENTS OF STANDARD MOLAR GIBBS ENERGIES OF FORMATION OF NIO, CU2O, AND COO FROM SOLID AND LIQUID-METALS AND OXYGEN GAS BY AN EMF METHOD AT HIGH-TEMPERATURES

E.m.f. measurements of the following galvanic cells with the solid oxide electrolyte (ZrO2 + CaO) were carried out to determine the standard molar Gibbs energies of formation of NiO, Cu2O, and CoO from solid and liquid metals and oxygen gas: (I) Pt|LaCrO3|Ni(s,1),NiO(s)|ZrO2+CaO|air|Pt, (II) Pt|LaCrO3|Cu(s,1),Cu2|ZrO2+CaO|air|Pt, (III) Pt|LaCrO3|Co(s,1),CoO(s)|ZrO2+CaO|air|Pt. The differences between the e.m.f.'s of cells (I) and (II), and of cells (I) and (III) were compared with the e.m.f.'s of the cells: (IV) Pt|Ni(s),NiO(s)|ZrO2+CaO|Cu(s,1),Cu2O(s,1)|LaCrO3Pt, (V) Pt|LaCrO3|Ni(s,1),NiO(s)|ZrO2+CaO|Co(s,1),CoO(s)|LaCrO3|Pt. The results were compared with previously reported values. © 1979.