JEE Main202621 January 2026Morning ShiftChemistryd and f Block ElementsActual
MnO ₄ ²⁻ , in acidic medium, disproportionates to :
Options
- AMnO ₄ ⁻ and MnO ₂
- BMn ₂ O ₇ and MnO ₂
- CMn ₂ O ₇ and MnO
- DMnO ₄ ⁻ and MnO
Correct answer
A. MnO ₄ ⁻ and MnO ₂
Step-by-step solution
MnO₄²⁻ (manganate) has Mn in +6 oxidation state. In acidic medium, it undergoes disproportionation where Mn is simultaneously oxidized and reduced: Oxidation: +6 +7 (forms MnO₄^- , permanganate) Reduction: +6 +4 (forms MnO₂ ) Reaction: 3MnO₄²⁻ + 4H^+ 2MnO₄^- + MnO₂ + 2H₂O