Q. The complex showing a spin-only magnetic moment of 2.82 BM is
A) $Ni(CO)_{4}$
B) $\left\lbrack {NiCl}_{4} \right\rbrack^{2 -}$
C) $Ni\left( {PPh}_{3} \right)_{4}$
D) $\left\lbrack Ni(CN)_{4} \right\rbrack^{2 -}$
Explanation
(b)
$Ni\ :3d^{8}4s^{2}$ $Ni^{2 +}\ :3d^{8}$
Since, Cl is a weak field ligand, it doesn’t cause paring of electron.
[table] ⥮ | ⥮ | ⥮ | $\upharpoonleft$ | $\upharpoonleft$ | | | | | | [/table]
$3d^{8}$ $4s$ $4p$
Number of unpaired electrons, n=2
$\mu = \sqrt{n(n + 2)} = \sqrt{2(2 + 2)BM} = \sqrt{8}\ BM = 2.82\ BM$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.