Given below are two statements: 

Assertion (A): Cu cannot liberate hydrogen from acids.
Reason (R): Because it has positive electrode potential.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is not true but (R) is true
4. Both (A) and (R) are false.



Hint: Cu is a weak reducing agent than H+
Cu can not liberate hydrogen from acids because it has a positive electrode potential value. Metals having a negative value of electrode potential liberate H2 gas.
The electrode potential value of Cu is -0.34 V and H+electrode potential value is zero. 
Hence, option one is the correct answer.