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. 2M HCl
B. 6M `NH_(3)`
C. 6 M NaOH
D. `H_2S` gas

Explanation

`Fe^(3+) +Zn^(2+) +Cu^(2+) overset(6M NH_(3)) to underset("Brown ppt.")(Fe(OH)_(3)) + underset("Soluble") ([Zn(NH_(3))_(4)]^(2+)) + underset("Soluble")([Cu(NH_(3))_(4)]^(2+))`