Which of the following salt solutions will be coloured?

Options

A. `Zn(NO_3)_2`
B. `Mn(NO_3)_3`
C. `Co(NO_3)_3`
D. `FeCl_3`

Answer

B, C, D

Explanation

Only those solutions will be coloured which contains unpaired d electrons. `Zn^(3+)` does not have any unpaired electron, so it will be colourless. `Mn^(2+)` is `3d^4` with 4 unpaired electron, `Co^(2+)` is `3d^7` with 3 unpaired electrons and `Fe^(3+)` is `3d^5` with 5 unpaired electrons and so their solutions will be coloured.