Concentrated sodium hydroxiide can separate a mixture of:

Options

A. `Al^(3+) and Cr^(3+)`
B. `Cr^(3+) and Fe^(3+)`
C. `Al^(3+) and Zn^(2+)`
D. `Zn^(2+) and Pb^(2+)`

Answer

B

Explanation

`NaOH` separates when one of the metal cation form amphoteric oxide and other form basic oxide `Al^(3+),Cr^(3+),Zn^(2+),Pb^(2+)` amphoteric, `Fe^(3+)` basic.