Chemistry - Coordination Chemistry Question with Solution | TestHub

$\begin{array}{rl}& {\left[\mathrm{V}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}\to {\mathrm{d}}^2{\mathrm{sp}}^3\\ & {}_{23}\mathrm{V}:-[\mathrm{Ar}]3{\mathrm{d}}^{3}4{\mathrm{s}}^2\\ & {\mathrm{V}}^{+3}:-[\mathrm{Ar}]3{\mathrm{d}}^2,\mathrm{n}=2\text{ (even number of unpaired }{\mathrm{e}}^{-})\\ & {\left[\mathrm{Cr}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}\to {\mathrm{sp}}^3{\mathrm{d}}^2\\ & {}_{24}\mathrm{Cr}:-[\mathrm{Ar}]3{\mathrm{d}}^{5}4{\mathrm{s}}^1\\ & {\mathrm{Cr}}^{+2}:-[\mathrm{Ar}]3{\mathrm{d}}^4,\mathrm{n}=4\text{ (even number of unpaired }{\mathrm{e}}^{-})\end{array}$
$\begin{array}{rl}& {\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}\to {\mathrm{sp}}^3{\mathrm{d}}^2\\ & {\mathrm{Fe}}^{3+}:-[\mathrm{Ar}]3{\mathrm{d}}^{5}4{\mathrm{s}}^0\\ & \mathrm{n}=5\left(\text{ odd number of unpaired }{\mathrm{e}}^{-}\right)\\ & {\left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}\to {\mathrm{sp}}^3{\mathrm{d}}^2\\ & \mathrm{Ni}:-[\mathrm{Ar}]3{\mathrm{d}}^{8}4{\mathrm{s}}^2\\ & {\mathrm{Ni}}^{+3}:-[\mathrm{Ar}]3{\mathrm{d}}^7,\mathrm{n}=3\text{ (odd number of unpaired }{\mathrm{e}}^{-})\\ & {\left[\mathrm{Cu}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}\to {\mathrm{sp}}^3{\mathrm{d}}^2\\ & \mathrm{Cu}:-[\mathrm{Ar}]3{\mathrm{d}}^{9}4{\mathrm{s}}^0\\ & \mathrm{n}=1\text{ (odd number of unpaired }{\mathrm{e}}^{-})\end{array}$