${\mathrm{KMnO}}_4$ is a strong oxidising agent in acidic,alkaline or neutral medium as well

Thiosulphate is oxidised almost quantitatively to sulphate:

$8{\mathrm{MnO}}_4{}^{-}+3{\mathrm{S}}_2{\mathrm{O}}_3{}^{2-}+{\mathrm{H}}_2\mathrm{O}⟶8{\mathrm{MnO}}_2+6{\mathrm{SO}}_4{}^{2-}+2{\mathrm{OH}}^{-}$

The equivalent weight of ${\mathrm{KMnO}}_4$ in the above reaction =$\frac{158}{5}$

 

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