Chemistry

In strong ligand field ${\mathrm{C}\mathrm{o}}^{3+}$ will have ${\mathrm{t}}_{2\mathrm{g}}^6{\mathrm{e}}_{\mathrm{g}}^0$ of configuration and $\mathrm{\Delta }\mathrm{t}=\frac{4}{9}{\mathrm{\Delta }}_0$

Is bulky base, so elimination is dominating.

$\mathrm{}{\mathrm{C}\mathrm{N}}^{-}\Rightarrow 14$ electrons, so $\mathrm{B}.\mathrm{O}=3$  and diamagnetic.

Theory based   

$\mathrm{}{\mathrm{M}\mathrm{A}}_2{\mathrm{B}}_2$ shows geometrical and not optical isomerism

Carbon-chlorine bond cleavage is not possible in ${\mathrm{C}\mathrm{H}}_3=\mathrm{C}\mathrm{H}-\mathrm{C}\mathrm{l}$

Kindly consider the following figure

Each ion makes a definite contribution irrespective of the other ion

$\begin{array}{rr}& {\left({\mathrm{\Lambda }}_{\mathrm{m}}^0\right)}_{\mathrm{N}\mathrm{a}\mathrm{B}\mathrm{r}}-{\left({\mathrm{\Lambda }}_{\mathrm{m}}^0\right)}_{\mathrm{N}\mathrm{a}\mathrm{l}}={\mathrm{\Lambda }}_{{\mathrm{m}\mathrm{B}\mathrm{r}}^{-}}^0-{\mathrm{\Lambda }}_{{\mathrm{m}}_{{\mathrm{r}}^{-}}}^0\\ & {\left({\mathrm{\Lambda }}_{\mathrm{m}}^0\right)}_{\mathrm{K}\mathrm{B}\mathrm{r}}-{\left({\mathrm{\Lambda }}_{\mathrm{m}}^0\right)}_{\mathrm{N}\mathrm{a}\mathrm{B}\mathrm{r}}={\mathrm{\Lambda }}_{{\mathrm{m}\mathrm{K}}^{+}}^0-{\mathrm{\Lambda }}_{{\mathrm{m}\mathrm{N}\mathrm{a}}^{+}}^0\end{array}$