Chemistry - Coordination Chemistry Question with Solution | TestHub

The complex is ${\left[\mathrm{Ni}{\left({\mathrm{NH}}_3\right)}_6\right]}^{2+}$. Ni is in the +2 oxidation state.

Electronic configuration of ${\mathrm{Ni}}^{2+}$ is $[\mathrm{Ar}]3d^8$.

${\mathrm{NH}}_3$ is a strong field ligand.

If Hund's rule is violated, electrons pair up in the $3d$ orbitals.

The hybridization becomes $s{p}^3{d}^2$.

Since all electrons are paired, the complex is diamagnetic.

Therefore, the correct statement is $s{p}^3{d}^2$ and diamagnetic.