How is `KMnO_(4)` [Potassium permanganate] is prepared from `MnO_(2)`? Write equations.

Explanation

Preparation of `KmNO_(4)` : Potassium permanaganate is pepared by the fusion of `MnO_(2) ` with an alkali metal hydroxide and an oxidizing agent like `KNO_(3)` . It forms dark green `K_(2)MnO_(4)` which disproportionates in a neutral of acidic solution to give permanganate
(i) `2MnO_(2)+4KOH+O_(2)overset("KNO_(3))to2K_(2)MnO_(4)+2H_(2)O`
(ii) `3MnO_(4)^(2-)+4H^(+)to 2MnO_(4)^(-)+MnO_(2)+2H_(2)O` or
`3K_(2)MnO_(4)+2H_(2)SO_(4)to underset"Potassium Permanganate"(2KMnO_(4))`