Statement I: Cis isomer of \([Co(en)_2Cl_2]Cl\) shows optical activity

Statement II: Cis isomer of \([Co(en)_2Cl_2]Cl\) is a symmetrical

Statement I is correct but Statement II is false

The correct option is 3. Statement I is correct but Statement II is false.

Statement I: Cis isomer of \([Co(en)_2Cl_2]Cl\) shows optical activity.

Statement II: Cis isomer of \([Co(en)_2Cl_2]Cl\) is symmetrical.

Statement I is correct. The cis isomer of \([Co(en)_2Cl_2]Cl\) shows optical activity because it lacks a plane of symmetry. Optical activity is observed in chiral molecules that do not possess a plane of symmetry. In the cis isomer, the two ethylenediamine ligands (\(en\)) are oriented differently relative to the central cobalt atom and chloride ligands, resulting in a chiral molecule.

Statement II is false. The cis isomer of \([Co(en)_2Cl_2]Cl\) is not symmetrical. As mentioned earlier, it is chiral due to its lack of a plane of symmetry. A molecule is chiral if it cannot be superimposed on its mirror image, and in this case, the cis isomer does not possess a plane of symmetry.