The number of unpaired electrons responsible for the paramagnetic nature of the following complex species are respectively : [Fe(CN)6]3-, [FeF6]3-, [CoF6]3-, [Mn(CN)6]3-
- 1, 5, 4, 2
- 1, 4, 4, 2
- 1, 5, 5, 2
- 1, 1, 4, 2
Answer
(1) 1, 5, 4, 2
Solution
[Fe(CN)6]3-: Fe3+, 3d5; strong field CN- t2g5 eg0 1 unpaired
[FeF6]3-: Fe3+, 3d5; weak field F- t2g3 eg2 5 unpaired
[CoF6]3-: Co3+, 3d6; weak field t2g4 eg2 4 unpaired
[Mn(CN)6]3-: Mn3+, 3d4; strong field t2g4 eg0 2 unpaired
1, 5, 4, 2
Answer: (1)