When a copper wire is exposed to air at room temperature, it becomes coated with a black...

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, At a still higher temperature, the oxide coating disappears. Explain these observations in terms of the thermodynamics of the reactions

and estimate the temperatures at which the changes occur.