Consider the following reaction MnO2 + KOH + O2 A + H2O. Product 'A' in neutral or acidic medium disproportionate to give products 'B' and 'C' along with water. The sum of spin-only magnetic moment values of B and C is BM. (nearest integer) (Given atomic number of Mn is 25)
Answer
4
Solution
2MnO2 + 4KOH + O2 2K2MnO4 + 2H2O ⇒ A = K2MnO4
3MnO42- + 4H+ 2MnO4- + MnO2 + 2H2O ⇒ B, C = KMnO4, MnO2
KMnO4: Mn7+, 3d0 ⇒ n = 0 ⇒ μ = 0
MnO2: Mn4+, 3d3 ⇒ n = 3 ⇒ = 3(3 + 2) = 3.87 BM
∴ Sum = 0 + 3.87 ≈ 4 BM
Answer: 4