Question

Aqueous solution of $N{i}^{2+}$ contains $\left[Ni\right(H_{2}O{)}_6{]}^{2+}$ and its magnetic moment is $2.83BM$. When ammonia is added in it, comment on the magnetic moment of solution.

• A. It will remains same
• B. It increases from $2.83BM$
• C. It decreases from $2.83BM$
• D. It cannot be predicted theoretically

Answer 1

The correct option is A It will remains same

$N{i}^{2+}\left(3d^8\right)$ ion contains two unpaired electrons irrespective of the strength of the ligand field strength.

Hence, its magnetic moment is 2.83 BM. It is not affected when water ligand is replaced with ammonia ligand.

$\underset{{\mu }_{eff}=2.8BM}{\underset{s{p}^3{d}^{2}Hyb.}{\left[Ni\right(H_{2}O{)}_6{]}^{2+}}}+6N{H}_2\rightleftharpoons \underset{{\mu }_{eff}=2.8BM}{\underset{s{p}^3{d}^{2}Hyb.}{\left[Ni\right(N{H}_3{)}_6{]}^{2+}}}+6H_{2}O$

Hence, the correct option is A.