Question

Which of the following compounds is coloured
A. `TiCl_(3)`
B. `FeCl_(3)`
C. `CoCl_(2)`
D. All of these

Answer 1

Correct Answer - D
The compounds having metal ions with unpaired electrons, are coloured. Thus, in `TiCl_(3)`
`Ti^(3+) = [Ar]3d^(1) (` one unpaired electron ) in `FeCl_(3)`
`Fe^(3+)= [Ar]3d^(5) (` Five unpaired electrons)in `CoCl_(2)`
`Co^(2+) = [Ar]3d^(7)` ( Three unpaired electrons )
Hence, all compounds are coloured.