The possible number of the stereo isomers in `[Cr(en)_(2)Cl_(2)]^(o+)` is .

The possible number of the optical isomers in [Cr(en)_(2)CI_(2)]^(o+) is .

The possible number of the optical isomers in [Cr(en)_(2)CI_(2)]^(o+) is .

The possible number of optical isomers in [Co(en)_(2)Cl_(2)]^(+) are

The total number of optically active isomers of [Pt(en)_(2)Cl_(2)]^(2+) is :

Name the following coordination entities and draw the structures of their stereoisomers : (i) [Co(en)_(2)Cl_(2)]^(+) (en = ethane-1,2-diamine (ii) [Cr(C_(2)O_(4))_(3)]^(3-) (iii) [ Co(NH_(3))_(3)Cl_(3)] (Atomic number Cr = 24 , Co = 27)

The possible geometric isomers of the complex , [Co(en) Br_2Cl_2]^(-) is :