Chemistry - Coordination Chemistry Question with Solution | TestHub

$$\text{ The cis and trans both form of complex }\left[M{\left({\mathrm{NH}}_3\right)}_4{\mathrm{Cl}}_2\right]\text{ are optically inactive }$$
There are plane of symmetry in addition to that there is alternate axis of symmetry $\left(C_n\right)$ which also causes their optical inactivity. A molecule possesses $n$ fold alternating axis of symmetry, if when rotated through an angle of $360^{\circ }/\mathrm{n}$ about the axis and then followed by reflection in a plane perpendicular to the axis, the molecule is indistinguishable from the original molecule.