Given below are two statements :
Statement (I) : Fusion of MnO₂ with KOH and an oxidising agent gives dark green K₂ MnO₄.
Statement (II) : Manganate ion on electrolytic oxidation in alkaline medium gives permanganate ion.
In the light of the above statements, choose the correct answer from the options given below :

Solution

Chemistry ma’am · 3 steps

These two statements are the two steps of making KMnO₄: Mn goes from +4 to +6, then +6 to +7.

1. Step one, fusion. MnO₂ is fused with KOH and an oxidising agent such as O₂ or KNO₃. Mn is oxidised from +4 to +6, giving dark green potassium manganate, K₂MnO₄. So Statement I is true.

   2MnO₂ + 4KOH + O₂ → 2K₂MnO₄ + 2H₂O

2. Step two, electrolysis. The green manganate ion is oxidised at the anode in alkaline solution. It loses one electron, MnO₄²⁻ → MnO₄⁻ + e⁻, and Mn goes from +6 to +7, giving purple permanganate. So Statement II is true.
3. So. Both statements correctly describe the commercial preparation of KMnO₄, so the answer is (d).

The idea to keep. Remember the KMnO₄ route as a colour and oxidation-state ladder: black MnO₂ (+4), green manganate (+6), purple permanganate (+7). Each step is an oxidation.

Answer from the NTA final answer key. Solution by PrepWiser.