The oxidising power of [CrO4]2-, [MnO4]2- and [FeO4]2- follows the order

Question

The oxidising power of [CrO4]2-, [MnO4]2- and [FeO4]2- follows the order (A) [CrO4]2-< [MnO4]2-< [FeO4]2- (B) [FeO4]2-< [MnO4]2-< [CrO4]2- (C) [MnO4]2-< [FeO4]2-< [CrO4]2- (D) [CrO4]2-< [FeO4]2-< [MnO4]2-

Tardigrade Admin · Accepted Answer

All have +6 oxidation state but due to smaller size on going from Cr to Fe, charge density increases from Cr to Fe and hence tendency to accept e- increases ∴ oxidising power [CrO4]2-< [MnO4]2-< [FeO4]2-

Q. The oxidising power of $[C r O_{4}]^{2 -}, [M n O_{4}]^{2 -}$ and $[F e O_{4}]^{2 -}$ follows the order

$[C r O_{4}]^{2 -} < [M n O_{4}]^{2 -} < [F e O_{4}]^{2 -}$

$[F e O_{4}]^{2 -} < [M n O_{4}]^{2 -} < [C r O_{4}]^{2 -}$

$[M n O_{4}]^{2 -} < [F e O_{4}]^{2 -} < [C r O_{4}]^{2 -}$

$[C r O_{4}]^{2 -} < [F e O_{4}]^{2 -} < [M n O_{4}]^{2 -}$

All have $+ 6$ oxidation state but due to smaller size on going from $C r$ to $F e$ , charge density increases from $C r$ to $F e$ and hence tendency to accept $e^{-}$ increases
$∴$ oxidising power $[C r O_{4}]^{2 -} < [M n O_{4}]^{2 -} < [F e O_{4}]^{2 -}$

Q. The oxidising power of [CrO4​]2−,[MnO4​]2− and [FeO4​]2− follows the order

[CrO4​]2−<[MnO4​]2−<[FeO4​]2−

[FeO4​]2−<[MnO4​]2−<[CrO4​]2−

[MnO4​]2−<[FeO4​]2−<[CrO4​]2−

[CrO4​]2−<[FeO4​]2−<[MnO4​]2−