Chemistry - Coordination Chemistry Question with Solution | TestHub

$\left(1\right){\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_4{\mathrm{Cl}}_2\right]}^{+}$show cis-trans isomerism.
$\left(2\right)\left[{\mathrm{CoCl}}_2(\mathrm{en}{)}_2\right]$show cis-trans isomerism.
$\left(3\right)\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_3{\left({\mathrm{NO}}_2\right)}_3\right]$show fac-mer isomerism.
$\left(4\right)\left[\mathrm{Co}{\left(\mathrm{CN}\right)}_5\right(\mathrm{NC}){]}^{3-}$can't show geometrical isomerism due to the presence of plane of symmetry.