Question

On reduction of $KMn{O}_4$ by oxalic acid in acidic medium, the oxidation number of Mn chnages. What is the magnitude of this change?

• A. $7$ to $2$
• B. $6$ to $2$
• C. $5$ to $2$
• D. $7$ to $4$

Answer 1

The correct option is A $7$ to $2$

In acidic medium reduction of $KMn{O}_4$ takes place as follows:

$Mn{O}_4^{-}+5e^{-}+8H^{+}\to {Mn}^{+2}+{4H}_{2}O+5e^{-}$

So oxidation state of $Mn$ changes from +7 to +2.