How do we differentiate between `Fe^(3+)` and `Cr^(3+)` in group III ?

Options

A. By taking excess of `NH_(4)OH` solution
B. By increasing `NH_(4)^(+)` ion concentration
C. By decreasing `OH^(-)` ion concentration
D. Both (b) and (c)

Answer

D

Explanation

`NH^(+)` ions are increased to suppress release of `OH^(-)` ions, hence solubility product of `Fe^(3+)` is attained. Colour of precipitate is different