The dark purple colour of $\mathrm{KMnO}_{4}$ disappears in the titration with oxalic acid in acidic

Question

The dark purple colour of $\mathrm{KMnO}_{4}$ disappears in the titration with oxalic acid in acidic medium. The overall change in the oxidation number of manganese in the reaction is\

Professor PC Thomas Classes · Answer

(a) : $\mathrm{MnO}_{4}^{-}+8 \mathrm{H}^{+}+5 e^{-} ightarrow$ $$ \mathrm{Mn}^{2+}+4 \mathrm{H}_{2} \mathrm{O} $$ Oxidation state of Mn changes from +7 to +2 .\ ∴ Change in oxidation number of manganese $=5$\