Question

A solution containing one mole per litre each of Cu(NO₃)₂ , AgNO₃ , Hg₂(NO₃)₂ , Mg(NO₃)₂ is being electrolysed by using inert electrodes. The values of standard potentials are

With increasing voltage, the sequence of deposition of metals on the cathode will be

(A) Ag, Hg, Cu, Mg 

(B) Mg, Cu, Hg, Ag 

(C) Ag, Hg, Cu 

(D) Cu, Hg, Ag

Answer 1

Correct option (C) Ag, Hg, Cu 

Explanation : 

The metal ions will be get preferentially deposited on the cathode in order of their decreasing reduction potentials. The order of deposition of metals will be Ag, Hg and Cu. Mg will not be deposited because H⁺ will be preferentially discharged.