(i) Write the geometrical isomer of the complex `[Co(en)_(2)Cl_(2)]^(+)` .
(ii) `[NiCl_(4)]^(2-)` is paramagnetic while `[Ni(CN)_(4)]^(2-)` is diamagnetic through both are tetrahedral . Why ?

Explanation

(i) N/A
(ii) In `[NiCl_(4)]^(2-)` , the `Cl^(-)` ion being a weak ligand does not cause the pairing of 3d electrons . Therefore , `[NiCl_(4)]^(2-)` is paramagnetic while `[Ni(CN)_(4)]^(2-)` IS DIAMAGNETIC IN NATURE .