Question

Column $-$ I

Column $-$ II

( where AB $\to$ Unsym. bidentate ligand having no chiral center, a, b, c, d & e $\to$ monodentate ligands )

Answer 1

The complex of the type ${\left[M{a}_{2}bcde\right]}^{n\pm }$ contains 3 optically inactive isomers.
The complex of the type ${\left[M{a}_2{b}_2{c}_2\right]}^{n\pm }$ contains 6 stereo( space ) isomers and 2 optically active isomers.
The complex of the type ${\left[M{a}_{3}bcd\right]}^{n\pm }$ contains 3 optically inactive isomers, 4 geometrical isomers and 2 optically active isomers.
The complex of the type ${\left[M\left(AB\right)c_2{d}_2\right]}^{n\pm }$ contains 4 geometrical isomers and 6 stereo( space ) isomers.