Alkaline oxidative fusion of MnO2 gives "A" which on electrolytic oxidation in alkaline solution produces B. A and B respectively are
- Mn2O3 and MnO42-
- Mn2O7 and MnO4-
- MnO42- and MnO4-
- MnO42- and Mn2O7
Answer
(3) MnO42- and MnO4-
Solution
Fusion: 2MnO2 + 4KOH + O2 2K2MnO4 + 2H2O ⇒ A = MnO42- (green manganate, Mn +6)
Electrolytic oxidation (alkaline, at anode): MnO42- MnO4- + e- ⇒ B = MnO4- (purple permanganate, Mn +7)
∵ this is the commercial preparation of KMnO4
Answer: (3)