The magnetic moment (spin only) of `[NiCl_4]^(2+)` is

Options

A. (a) `1.82 BM`
B. (b) `5.46 BM`
C. (c) `2.82 BM`
D. (d) `1.41 BM`

Answer

C

Explanation

`[NiCl_4]^(2-)`, oxidation number of `Ni`, `x-4=-2`
`:. x=+2`, `Ni_((28))[Ar]3d^8, 4s^2`

`sp^3`-hybrid orbitals, tetrahedral
Since, `Cl^(-)` is a weak ligand, thus unpaired electrons are not paired. Lone pairs from `4Cl^(-)` are accommodated in four `sp^3` hybrid orbitals.
n=unpaired electron=2, paramganetic
Magnetic moment (spin only)
`=sqrt(n(n+2))BM=sqrt8=2.828BM`