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# Indicate the steps in the preparation of: KMnO_{4} from pyrolusite ore.

8.26 Indicate the steps in the preparation of:

(ii) $KMnO_{4}$ from pyrolusite ore.

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Potassium permanganate can be prepared from the fusion of pyrolusite ore($MnO_{2}$) with an alkali metal hydroxide and an oxidising agent (like $KNO_{3}$).

This gives dark green $K_{2}MnO_{4}$. It disproportionates in acidic or neutral medium to give permanganate.

$\\2MnO_{2}+4KOH+O_{2}\rightarrow 2K_{2}MnO_{4}+2H_{2}O\\ 3MnO_{4}^{2-}+4H^{+}\rightarrow 2MnO_{4}^{-}+MnO_{2}+H_{2}O$

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