Question

MnO₂ + KOH + O₂→ A 

‘A’ disproportionate into ‘B’ and ‘C’. Find the sum of magnetic moment (spin only) (in B.M.) of B and C (Nearest integer)

Answer 1

Correct answer is :  4

B and C are \(MnO_4^{-}\) and MnO₂

Mn in MnO₂ has +4 oxidation state hence it has (n-1)d³ ns⁰ electronic configuration 

unpaired e = 3 

Mag. moment : 3.87 B.M by \(\sqrt{n(n+2)}\) 

KMnO₄/\(MnO_4^{-}\) is diamagnetic hence magnetic moment =0 because it has no unpaired electron. Hence, sum of mag. moment = 3.87 B.M. 

Nearest integer = 4