Question

Assertion :Equivalent mass of $KMn{O}_4$ is equal to one-third of its molecular mass when it acts as an oxidising agent in an alkaline medium. Reason: Oxidation number of $Mn$ is +7 in $KMn{O}_4$.

• 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

$KMn{O}_4$ as an oxidizer in basic media:
$Mn{O}_4^{-}+2H_{2}O+3e^{-}\to Mn{O}_2\left(s\right)+4O{H}^{-}$ (gained 3 electrons)
Equivalent weight of $KMn{O}_4=\frac{158.04}{3}=52.68$ grams/equivalent

Oxidation nhumber of $Mn$ is +7 in $KMn{O}_4$