Question

The metals that cannot be obtained by electrolysis of the aqueous solution of their salts are:

• A. $Ag$
• B. $Mg$
• C. $Cu$
• D. $Al$

Answer 1

Answer: (B), (D)

$Mg$
$Al$

Highly reactive metals with lower reduction potentials than hydrogen are not obtained by electrolysis of aqueous solutions of their salts since their cations cannot be reduced at cathode in presence of water. Instead of reduction of these metal cations, water undergoes reduction.

$Al$ and $Mg$ are reactive metals with lower reduction potentials.

Usually d-block elements are less reactive and hence can be prepared by electrolysis of their aqueous solutions.