Question

The metal which cannot be produced on reduction of its oxide by aluminium is :

• A. $K$
• B. $Mn$
• C. $Cr$
• D. $Fe$

Answer 1

The correct option is A $K$

Potassium is more electropositive than aluminium.

Hence, it cannot be prepared by the reduction of the oxide of potassium with aluminium.

Mn, Cr and Fe are less electropositive than aluminium.

Hence, they can be prepared by the reduction of their oxides with aluminium.

Hence, the correct option is $\text{A}$