Among `(A)` `TiF_(6)^(2-),(B) CoF_(6)^(3-), (C ) Cu_(2)CI_(2)` and` (D) NiCI_(4)^(2)`
(atomic number of `Ti=22,Co=27,Cu=29,Ni=28)` the colourless species are
(a) `(B)` and `(D)`
(b) `(A)` and `(B)`
`C ` and (D)`
`(A)` and `(C )` .

Answer

d

Explanation

Completely filled d-orbital system or completely unfilled d-orbital system are colourless Thus colour of a complex is explained on the basis of d-transition
`{:(In,Cu_2Cl_2,Cu,is i n,+1OS),(i.e.,3d^(10),system,and,),(i n,TiF_6^(2-),Ti,is i n,+4OS),(i.e.,3d^(0),system,,):}}"Colourless"` .