Reduction of the metal centre in aqueous permanganate ion involves:

The reactions of permanganate ion in different media are given below:

Acidic medium:
MnO₄⁻(aq) + 8H⁺(aq) + 5e⁻ → Mn²⁺(aq) + 4H₂O(l)
In acidic medium, permanganate ion accepts 5 electrons and gets reduced to Mn²⁺ ion.

Neutral medium:
2MnO₄⁻(aq) + 3H₂O(l) + 2e⁻ → 2MnO₂(s) + 6OH⁻(aq)
In neutral medium, permanganate ion accepts 3 electrons and gets reduced to MnO₂.

Alkaline medium:
2MnO₄⁻(aq) + H₂O(l) + 2e⁻ → 2MnO₄²⁻(aq) + 2OH⁻(aq)
In alkaline medium, permanganate ion accepts 1 electron and gets reduced to manganate ion (MnO₄²⁻).