Question

Assertion (A): Cu cannot liberate H$_2$ on reaction with dilute mineral acids.
Reason (R): Cu has positive electrode potential.

• (A) and (R) are true, and (R) is the correct explanation of (A).
• (A) and (R) are true, but (R) is not the correct explanation of (A).
• (A) is true, but (R) is false.
• (A) is false, but (R) is true.

Hint:

When studying reactivity of metals with acids, remember that only metals with a more negative electrode potential can liberate hydrogen gas from acids.

Answer 1

The Correct Option is C

Copper (Cu) does not liberate H$_2$ gas when it reacts with dilute mineral acids like HCl because it is less reactive than hydrogen and does not displace it from its salts. The electrode potential of Cu is positive, but this does not explain its inability to liberate hydrogen. Reason (R) is false as it provides an incorrect explanation.