Question
MnO _ 4 ^ 2- , in acidic medium, disproportionates to :
JEE Main
Chemistry
d and f Block Elements
2026
JEE Main 2026 (21 January Shift 1)
JEE Main Chemistry Question (2026) — Solution
Options
- A. MnO _ 4 ^ - and MnO _ 2
- B. Mn _ 2 O _ 7 and MnO _ 2
- C. Mn _ 2 O _ 7 and MnO
- D. MnO _ 4 ^ - and MnO
Answer
A. MnO _ 4 ^ - and MnO _ 2
Step-by-step solution
MnO_4^ 2- (manganate) has Mn in +6 oxidation state. In acidic medium, it undergoes disproportionation where Mn is simultaneously oxidized and reduced: Oxidation: +6 +7 (forms MnO_4^-, permanganate) Reduction: +6 +4 (forms MnO_2) Reaction: 3MnO_4^ 2- + 4H^+ 2MnO_4^- + MnO_2 + 2H_2O
Related: Chemistry — d and f Block Elements · All PYQ Banks