Question

Give one example of an electrolytic decomposition reaction used in metallurgy.

Answer 1

Hint:Before giving the example, we will know about the electrolytic decomposition reaction and metallurgy. Electrolytic decomposition reaction can be explained from the name itself. We know what the decomposition reaction is. When a compound is broken to its constituent ions, it is called decomposition reaction.

Complete step by step answer:
Generally, decomposition reactions occur when energy sources like light, heat or electricity are introduced. This type of reaction is known as electrolytic decomposition reaction. It is also called electrolysis. Electrolysis is the process of conversion of a compound to its ions by introducing electricity to the solution. In this reaction, cathode and anode is involved.
There is a branch of science in which purification of metals and its properties are involved. This is called metallurgy. When this purification of metals is done with electricity, it is called electrometallurgy. Electrolysis in metallurgy is applied in the production of aluminium. This process is called Hall-Heroult electrolysis process. Aluminium is extracted from bauxite. The reaction is given below:
$2{{A}}{{{l}}_2}{{{O}}_3} \to 4{{Al}} + 3{{{O}}_2}$
In this process, electrolysis occurs when the melting point of cryolite is low. Thus ${{A}}{{{l}}_2}{{{O}}_3}$ is dissolved in cryolite, which is in molten form. This helps to increase the conductivity of the solution. The melting point of cryolite decreases from ${1012^ \circ }{{C}}$ to ${1000^ \circ }{{C}}$ when we add the alumina. Now these are electrolyzed when electricity of voltage $3 - 5{{V}}$ is passed.
In cathode, aluminium is deposited and carbon dioxide is obtained.

Note:
Some other examples for electrolytic decomposition reaction used in metallurgy are refining of copper and silver. Recycled silver is recovered through electrolysis which produces crystal silver. There are some other uses for electrolysis. It is used for coating a metal with another and also in electroplating.