Question

In neutral or faintly alkaline medium, $KMn{O}_4$ being a powerful oxidant can oxidize, thiosulphate almost quantitatively, to sulphate. In this reaction overall change in oxidation state of manganese will be :

Answer 1

${\stackrel{+7}{8MnO}}_4^{-}+3S_2{O}_3^{2-}+H_{2}O\to \stackrel{+4}{8Mn{O}_2}+6S{O}_4^{2-}+2O{H}^{-}$
Change in oxidation state of $Mn$ is from $+7$ to $+4$ which is $3$.