Question
How can the black coating of copper oxide be removed chemically?
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Answer
- The black coating of copper oxide can be removed chemically by passing the hydrogen gas over heated copper oxide. As a result, the black coating turns brown in colour as oxygen is removed by hydrogen.
- $\mathrm{CuO}+\mathrm{H}_2 \rightarrow \mathrm{Cu}+\mathrm{H}_2 \mathrm{O}$
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