TY - JOUR
T1 - Studies on thermodynamic properties of copper in molten NaOH
AU - Hayashi, Hidetaka
AU - Yoshizawa, Shiro
AU - Ito, Yasuhiko
PY - 1983/10
Y1 - 1983/10
N2 - Thermodynamic behaviour of copper in molten NaOH at 623K (350°C) has been studied. The solubility product of cupric oxide, Ksp-2, was determined to be 2.5 × 10-12 by chemical analysis. The standard potential of the Cu Cu+ couple was found to be 1.97 V vs Na Na+ and that of the Cu+ Cu2 couple was 1.87 V vs Na Na+, respectively. Moreover, the standard potential of the Cu Cu2O and Cu2O CuO couples were determined by the use of stabilized zirconia and compared with the values derived from published thermochemical data. Finally Ksp-1, the solubility product of cuprous oxide, was evaluated to be 3.0 × 10-15. From the experiment, the following conclusions were obtained. 1. In this system, copper can be oxidized to its divalent state, such as cupric oxide or cupric ion, through its univalent state, such as cuprous ion or cuprous oxide, in the presence of oxygen. 2. Solubility products of the oxides of copper are much larger than that of nickel oxide, which behaves as a protective film. Thus, copper is not suitable for materials to be used in this media.
AB - Thermodynamic behaviour of copper in molten NaOH at 623K (350°C) has been studied. The solubility product of cupric oxide, Ksp-2, was determined to be 2.5 × 10-12 by chemical analysis. The standard potential of the Cu Cu+ couple was found to be 1.97 V vs Na Na+ and that of the Cu+ Cu2 couple was 1.87 V vs Na Na+, respectively. Moreover, the standard potential of the Cu Cu2O and Cu2O CuO couples were determined by the use of stabilized zirconia and compared with the values derived from published thermochemical data. Finally Ksp-1, the solubility product of cuprous oxide, was evaluated to be 3.0 × 10-15. From the experiment, the following conclusions were obtained. 1. In this system, copper can be oxidized to its divalent state, such as cupric oxide or cupric ion, through its univalent state, such as cuprous ion or cuprous oxide, in the presence of oxygen. 2. Solubility products of the oxides of copper are much larger than that of nickel oxide, which behaves as a protective film. Thus, copper is not suitable for materials to be used in this media.
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U2 - 10.1016/0013-4686(83)85194-9
DO - 10.1016/0013-4686(83)85194-9
M3 - Article
AN - SCOPUS:0020834896
VL - 28
SP - 1389
EP - 1394
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
IS - 10
ER -