Question

In the refining of copper, pure copper is deposited on:
A) Anode
B) Cathode
C) Both a and b
D) None of these

Answer 1

Hint: We must know that the impure form of copper is known as blister which also contains sulphur. By electro refining method, the pure copper is obtained from the impure copper. Try to write the chemical reactions taking place at the anode and cathode. The electrolyte should have the copper in so that it can be deposited as pure copper.

Complete step by step answer:
Copper is purified by the process of electrolysis. Electricity is passed through the solutions containing copper compounds like copper(ll)sulphate. The positive electrode i.e. the anode is made from impure copper. In negative electrodes (cathode), copper strips are used.
 During electrolysis anode loses as copper dissolves into the solution as copper ion. On a pure copper strip, the copper ions from solution are deposited which leads to an increase in the size of cathode. The heavy impurities do not oxidise so it settled as anode mud. The reaction happening at cathode and anode is given below:
Anode:\[Cu \to C{u^{2 + }} + 2{e^ - }\](Oxidation)
Cathode:\[C{u^{2 + }} + 2{e^ - } \to Cu\](Reduction)
At anode, oxidation takes place by the loss of electrons. At cathode, reduction takes place by gaining of electrons. By electrorefining process, at cathode pure copper deposited and at anode Au, Ag and pt as anode mud.
From the above explanation we can conclude that:
Acidified copper(II)sulphate is used as an electrolyte in electrolysis process,
Impure copper is used as anode,
Pure copper is used as cathode,
Impurities settle down as anode mud.

So the answer to this question is option B i.e. Cathode.

Note:We must remember that the chief ore for obtaining copper is copper pyrites \[(CuFe{S_2})\]. After the extraction process, copper sulphide and copper oxide are obtained. This is called copper matte. Copper matte I used to obtain pure copper through electrolysis. 99.9% of pure copper is obtained by electrolysis process.