CP13. When a copper wire is exposed to air at room temperature, it becomes coated with a black oxide, CuO. If the wire is heated above a certain temperature, the black oxide is converted to a red...

Extracted text: CP13. When a copper wire is exposed to air at room temperature, it becomes coated with a black oxide, CuO. If the wire is heated above a certain temperature, the black oxide is converted to a red oxide,Cu2O. At a still higher temperature, the oxide coating disappears. Explain these observations in terms of the thermodynamics of the reactions: 2 CuO(s) → Cu2O(s) + ½ O2(g) Cu2O(s) → 2 Cu(s) + ½ O2(g) and estimate the temperatures at which the changes occur.