Question

Assertion :$E_{cell}^{\circ }=0$ for a chloride ion concentration cell. Reason: For this concentration cell: $E_{cell}=\frac{RT}{nF}ln\frac{[C{l}^{-}{]}_{LHS}}{[C{l}^{-}{]}_{RHS}}$

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

The cells whose $E_{cell}^0$ is zero are called concentration cells. This means that the two compartments(cathode and anode) of the electrochemical cell involve the same chemical species but the concentrations of the chemical species in the two compartments are different.

Nernst equation:

$E=E^0-2.303\frac{RT}{nf}logQ$

$logQ=\frac{[C{l}^{-}{]}_{RHS}}{[C{l}^{-}{]}_{LHS}}$

So, $E_{cell}=\frac{RT}{nF}ln\frac{[C{l}^{-}{]}_{LHS}}{[C{l}^{-}{]}_{RHS}}$