Atomic number of Mn, Fe and Co an dNi are 25, 26 27 and 28 respectively. Which of the following outer orbital octahedral complexes have same number of unpaired electrons -

Options

A. `[MnCl_(6)]^(3-)`
B. `[FeF_(6)]^(3-)`
C. `[CoF]^(3-)`
D. `[Ni(NH_(3))_(6)]^(2+)`

Answer

A, C

Explanation

In outer orbital octahedral complexes, central metal ions are `sp^(3)d^(2)` hybridised. So in presence of respective ligands, electronic configurations of metal ions are -
(A) `Mn^(3+)=3d^(4)(=d^(1)d^(1)d^(1)d^(1)d^(0))`, 4 upaired electrons.
(B) `Fe^(3+)=3d^(5)(=d^(1)d^(1)d^(1)d^(1)d^(1))`, 5 unpaired electrons.
(C) `co^(3+)=3d^(6)(=d^(2)d^(1)d^(1)d^(1)d^(1))`, 4 unpaired electrons.
(D) `Ni^(2+)=3d^(8)(=d^(2)d^(2)d^(2)d^(1)d^(1))`, 2 unpaired electrons.