Question

Copper does not react with HCl to give $H_2$ gas. why?

• A. The reduction potential of copper is higher than hydrogen.
• B. The oxidation potential of copper is less than hydrogen.
• C. Copper is highly reactive metal.
• D. None of these.

Answer 1

The correct option is A The reduction potential of copper is higher than hydrogen.

To displace hydrogen from HCl, the metal must have lower standard electrode potential (or reduction potential) than hydrogen. Copper has higher reduction potential than hydrogen because of which copper will stay in reduced form, $Cu$, rather than oxidizing to $C{u}^{+}$ or $C{u}^{2+}$. Therefore, copper does not react with $HCl$ to give $H_2$ gas.

Thus the answer is (A) The reduction potential of copper is higher than hydrogen.