Question

During the electrolysis of copper sulphate aqueous solution using copper electrode, the reaction taking place at the cathode is:
a.) $Cu\to C{{u}^{2+}}_{(aq)}+2{{e}^{-}}$
b.) \[C{{u}^{2+}}(aq)+2{{e}^{-}}\to Cu(s)\]
c.) ${{H}^{+}}+{{e}^{-}}\to \dfrac{1}{2}{{H}_{2}}$
d.) $SO_{4}^{2-}\to S{{O}_{3}}(S)+\dfrac{1}{2}{{O}_{2}}+2{{e}^{-}}$

Answer 1

Hint: Electrolysis is a process in which extraction of desired metal is taken by the use of current. It has two electrodes cathode and anode. At cathode, there is release of electrons or the place where reduction takes place. At anode, electrons are accepted or oxidation takes place.

Complete answer:
Electrolysis is the process there is removal or addition of electrons by which atoms and ions are interchanged due to the applied current. Removal of the desired products of electrolysis can be done by various physical processes.
There are two types of electrodes present in electrolysis process:
1. Cathode
2. Anode

Two half reactions take place in the electrolysis process that is reduction half reaction and oxidation half reaction. Redox half reaction takes place at cathode and oxidation half reaction takes place at anode.
Anode is that half-cell where oxidation takes place and it is negatively charged in comparison to the solution.
Cathode is the half-cell where reduction takes place and it has positive potential in comparison to overall solution. There is potential difference between the two electrons and as soon as current is allowed to flow there is movement of charges from anode to cathode.
During the electrolysis of copper sulphate aqueous solution using copper electrode, the reaction taking place at the cathode is
\[C{{u}^{2+}}(aq)+2{{e}^{-}}\to Cu(s)\]
Cu (II) has low discharge potential in comparison to the protons so copper will be deposited at cathode than protons.

The correct option is B.

Note: In electrolysis, at cathode reduction takes place and at anode oxidation takes place. These two parts of the cell perform the half-cell reactions. At each electrode-electrolyte there is the capability of metal ions to get deposited on cathode and leave behind electrons at anode making it negatively charged.