Draw the structures of optical isomers of: `[Cr(C_2O_4)_3]^3-`

Draw the structure of BF3.

Draw the structures of optical isomers of: [PtCl_2(en)_2]^(2+)

Draw the structures of optical isomers of : Cr(NH_3)_2Cl_2 (en)]^+

Draw the structure of PCl_3 .

Draw structure of Cl_3 .

Draw structure of IF_3 .

Draw the structure of P_4O_10 .

Indicate the types of isomerism exhibited by the following complexes and draw the structures for these isomers: K[Cr(H_2O)_2(C_2O_4)_2]

Draw structures of geometrical isomers of [Fe(NH_3)_2(CN)_4]