Question

Which of the following methods is used for purification of mercury?
A. Liquation
B. Distillation
C. Electrolytic refining
D. Chemical reduction

Answer 1

Hint: Mercury is the only metal which exists in liquid state at room temperature. It has low boiling point compared to other metals, so that method is used which deals with the separation using the boiling point.

Complete step by step answer:
Metals in earth's crust are not found in their pure form. To extract metal various steps of metallurgy are as follows: Concentration of ore for removal of matrix, Conversion of concentrated ore into metal oxide by roasting and calcination. Reduction of metal oxide to metal (impure) and Refining to obtain pure metal from impure metal.
Refining or purification of metal is the last step of metallurgy, in this process pure metal is extracted from impure metal. It can be done in various ways, as follows by liquation when, melting point of metal is less than impurities, For example lead, tin, antimony and bismuth.
Distillation is used when boiling point of metal is less than impurities, for example zinc, cadmium and mercury.
 Vapour phase refining done by the help of vapour pressure, for example nickel and cadmium. Polling method is used when impurity is oxide of its own metal, example copper, lead and tin.
Electrolytic refining is done by using electricity or electrochemical cells, Ex Cu, Ag and Al. By cupellation when impurity is easily oxidized than metal, example impurity of silver and gold. Zone refining method is used for ultra refining of semiconductor, example germanium and silicon.

Thus, the correct option is B.

Note:
 There are more than 25 known minerals containing mercury, but the principal ore mineral is cinnabar, a soft red to reddish brown HgS that is mercuric sulphide.