Question

Find the cathode and anode product of electrolysis of ${\text{CuS}}{{\text{O}}_{\text{4}}}\left( {{\text{aq}}} \right){\text{/Cu}}$ electrode?

Answer 1

Hint:Electrolysis is a process in which ionic compounds decompose into their elements by passing an electric current through the compound in liquid form. The anions get oxidized at the anode and in case of cations they are reduced at the cathode.

Complete step by step answer:
1) The electrolysis of ${\text{CuS}}{{\text{O}}_{\text{4}}}\left( {{\text{aq}}} \right)$ using a copper electrode (an active electrode) results in the transfer of copper metal from anode to cathode. Copper sulfate in aqueous solution ionizes to give:
${\text{CuS}}{{\text{O}}_{\text{4}}} \to {\text{C}}{{\text{u}}^{2 + }} + {\text{SO}}_4^{2 - }$
2) The actual reactions occurring at the electrodes are as follows:
At cathode: ${\text{C}}{{\text{u}}^{2 + }}\left( {{\text{aq}}} \right) + 2{e^ - } \to {\text{Cu}}\left( {\text{s}} \right)$
At anode:${\text{Cu}}\left( {\text{s}} \right) \to {\text{C}}{{\text{u}}^{2 + }}\left( {{\text{aq}}} \right) + 2{e^ - }$
3) As we know that the reduction occurs at the cathode, then the positively charged copper ions will migrate towards the cathode where each ${\text{C}}{{\text{u}}^{2 + }}$ ion accepts two electrons to give copper metal which is deposited on the cathode. On the other hand, at the anode, each copper metal loses two electrons to give ${\text{C}}{{\text{u}}^{2 + }}$ ions.
4) If more than one substance is present in the electrolytic cell, the substance liberated at the cathode is the one having the highest reduction potential and which is liberated at the anode has the highest oxidation potential.
5) Electrolysis can be used in metallurgical processes i.e. in extraction or purification of metals from their ores or compounds and in the deposition of metal from the solution.

Note:
The aqueous solution of copper sulfate gives copper ion and sulfate ion. The sulfate ion does not participate in the reaction and the concentration of copper sulfate in the solution does not change. The reaction will complete when the anode is completely used or eaten away.