The type of isomerism shown by the complex $\left[{\mathrm{CoCl}}_2(en{)}_2\right]$ is

The type of isomerism shown by the complex $\left[{\mathrm{CoCl}}_2\right(\mathrm{en}{)}_2]$ is geometrical isomerism. This complex shows cis trans isomerism. In the cis form, two Cl ligands are adjacent to each other and two en ligands are adjacent to each other. In the trans form, two Cl ligands are opposite to each other and two en ligands are opposite to each other.