Question

Copper is purified by
A. Distillation
B. Liquidation
C. Carbon-reduction
D. Electrolysis

Answer 1

Hint: The method of purification depends upon the type of ore. Main ore of the copper is copper pyrite. Copper pyrite is a sulphide ore.

Step by step answer: Distillation is a purification method used to separate the mixture according to the boiling point of different components of the mixture. So, option (A) is incorrect.
Liquation is used to separate metals from ore on the basis of their melting point. One metal that has low temperature remains solid on heating whereas the other melts. The copper and zinc are separated from each other by liquation so, option (B) is incorrect.
Carbon-reduction is used to separate the metal from metal oxide, so option (C) is incorrect.
Electrolysis is a process used for the separation of metal and non-metals.
In electrolysis, the ionic compound of copper that is copper (II) sulphate is taken into the electrolytic cell which is known as an electrolytic solution. The cell also has two electrodes anode that is made up of impure copper and a cathode that is made up of pure copper. These electrodes are dipped into the electrolyte solution and electricity is passed through the solution.
The copper ions move from the anode into the electrolytic solution so, the thickness of the anode decreases with the time and copper ions from the solution move towards the cathode where ions get electrons and reduce so, the thickness of the cathode increases with the time.
Copper is purified by electrolysis, so option (D) is correct.

Therefore, option (D) electrolysis is correct.

Note: All the methods of purification depends upon the type of ore. Electrolysis is used for copper (II) sulphate. Carbon-reduction is used for copper oxide. Copper metal can be concentrated by liquation from ore containing zinc.