The green coloured complex ion of nicked in its aqueous solution is

Options

A. `[Ni(en)_(3)]^(2+) `
B. `[Ni(H_(2)O)_(2)(en)_(2)]^(2+)`
C. `[Ni(H_(2)O)_(4)(en)]^(2+)`
D. `[Ni(H_(2)O)_(6)]^(2+)`

Answer

D

Explanation

In complex `[Ni(H_(2)O)_(6)]^(2+)` the strong ligand is absent . Thus electrons do not go for pairing and two unpaired `e^(-)` are present in `Ni^(2+)` complex. Hence is a coloured complex.