Question

Sir could you please tell me what is valency factor of KMnO4.

And how to find it.

Thank you sir.

Answer 1

Acidic $KMn{O}_4$

• ​In an acidic medium, The $KMn{O}_4$ reduced as $Mn{O}_4^{-}+8H^{+}+5e^{-}⟶M{n}^{2+}+4H_{2}O$
• Here, the manganese with a valency of 7 is get reduced to a valency of 2
• Hence the change in oxidation state is $+7-2=+5$
• Hence, the valency factor of acidic $KMn{O}_4$ is $+5$

Alkaline $KMn{O}_4$

• In an alkaline medium, the $KMn{O}_4$ reduced as $Mn{O}_4^{-}+e^{-}⟶Mn{O}_4^{2-}$
• ​Here, the manganese with a valency of 7 is get reduced to a valency of 6
• Hence the change in oxidation state is $+7-6=+1$
• Hence, the valency factor of alkaline $KMn{O}_4$ is $+1$