NEETChemistryElectrochemistry
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Copper dissolves in dilute hydrochloric acid to evolve hydrogen gas. Reason (R): The standard reduction potential of Cu ²⁺/ Cu is positive and higher than that of H ⁺/ H ₂ . In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A).
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A).
- C(A) is true but (R) is false.
- D(A) is false but (R) is true.
Correct answer
D. (A) is false but (R) is true.
Step-by-step solution
Assertion (A) is false because copper does not dissolve in dilute hydrochloric acid to evolve hydrogen gas. Metals placed above hydrogen in the electrochemical series (having negative standard reduction potentials) can displace hydrogen from dilute acids. Copper is placed below hydrogen. Reason (R) is true because the standard reduction potential of the Cu ²⁺/ Cu electrode is +0.34 V , which is positive and higher than the standard reduction potential of the standard hydrogen electrode ( 0.00 V ). Therefore, Assert