The only cations present in a slightly acidic solution are `Fe^(3+),Zn^(2+)` and `Cu^(2+)` . The regent that when added in excess to this solution would identify and separate `Fe^(3+)` in one step is

Options

A. 2 M HCl
B. 6 M `NH_3`
C. 6 M NaOH
D. `H_2S` gas

Answer

B

Explanation

`Fe^(3+)+3NH_3+3H_2OtoFe(OH)_3 darr` (reddish-brown)+`3NH_4^+`
`Cu^(2+)+4NH_3 to [Cu(NH_3)_4]^(2+)`(deep blue solution)
`Zn^(2+)+4NH_3to[Zn(NH_3)_4]^(2+)`(colourless solution)