Question

Amongst FeCl3.3H2O, K3[Fe(CN)6)] and [Co(NH3)6]Cl3, the spin-only magnetic moment value of the inner-orbital complex that absorbs light at shortest wavelength is_______B.M. [nearest integer]

Answer 1

[Fe(H2O)3Cl3] → Outer-orbital complex

K3[Fe(CN)6] → Inner-orbital complex

[Co(NH3)6]Cl3 → Inner-orbital complex

Since CN– is a strong field ligand than NH3. Hence K3[Fe(CN)6] is the inner-orbital complex that absorbs light at shortest wavelength.

Fe(III) → valence shell configuration 3d5

Since CN– will do pairing, so unpaired electron = 1

$μ=\sqrt{1(1+2)}=\sqrt3BM=2BM$