Question

The number of unpaired electrons in ${\left[NiC{l}_4\right]}^{2-},Ni{\left(CO\right)}_4$ and ${\left[Cu{\left(N{H}_3\right)}_4\right]}^{2+}$ respectively are :

• A. $2,2,1$
• B. $2,0,1$
• C. $0,2,1$
• D. $2,2,0$

Answer 1

Answer: (B)

Configuration for metal $(M)$ in various complex.

$N{i}^{2+}$ has $2$ unpaired electrons

$N{i}^0$ has zero unpaired electrons with $s{p}^3$-hybridisation.

$C{u}^{2+}$ has one unpaired electron with $ds{p}^2$-hybridisation.
$\therefore (b)$ is the correct answer, i.e.
Number of unpaired electron $(2,0,1)$