Question

Assertion :Reduction potential of $Mn(+3$ to $+2)$ is more positive than $Fe(+3$ to $+2)$. Reason: Ionisation potential of $Mn$ is more than that of $Fe$.

• 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 C Assertion is correct but Reason is incorrect

$M{n}^{2+}=\left[Ar\right]3d^5,M{n}^{3+}=\left[Ar\right]3d^4$

$F{e}^{2+}=\left[Ar\right]3d^6,F{e}^{3+}=\left[Ar\right]3d^5$

Thus, $M{n}^{2+}$ has more stable configuration than $M{n}^{3+}$ while $F{e}^{3+}$ has more stable configuration than $F{e}^{2+}$. Hence, reduction potential for $M{n}^{3+}/M{n}^{2+}$ couple is more positive than $F{e}^{3+}/F{e}^{2+}$.