Question

Consider the reaction
$K_2\left[Ni\right(CN{)}_4]+N{H}_3+2K(potassium)\to complex(A)$
$complex\left(A\right)$ gives five ions in aqueous solution then choose correct statements.

• A. Complex is $s{p}^3$ hybridised and diamagnetic
• B. Complex is $s{p}^3$ hybridised and paramagnetic
• C. Complex is $ds{p}^2$ hybridised and diamagnetic
• D. In complex $\stackrel{\ominus }{C}N$ ligands are replaced by

Answer 1

The correct option is B Complex is $s{p}^3$ hybridised and paramagnetic

$A$ is $K_4\left[Ni\right(CN{)}_4]$ which exits as $4K^{+}$ and $\left[Ni\right(CN{)}_4{]}^{4-}$ in solution.

$\left[Ni\right(CN{)}_4{]}^{4-}\to Ni\to d^8{s}^2\to$

due to the strong field liquid $\left(CN\right)$ pairing of $s^{-}$ electrons takes place to give $d^{10}{s}^o$ and $4C{N}^{-}$ gives $S{p}^3$ as hybridisation.