Question

__________ is the by-product obtained in the Serpek’s process?
A.Oxygen
B.Ammonia
C.Nitrogen dioxide
D.Nitric oxide

Answer 1

Hint: We have to remember that the Serpek’s process is mainly used for bauxite ore, which contains the silica as impurity. Bauxite is a sedimentary rock which contains a high amount of aluminum. The cock is mixed with the powdered ore of bauxite by applying high temperature in the presence of nitrogen gas. And there is a formation of carbon monoxide, aluminium nitride and water.

Complete answer:
We need to know that in Serpek’s process, the bauxite is reacting with cock and there will not be a formation of oxygen as a by-product. Hence, the option (A) is incorrect.
Serpek’s process is mainly used for the purification of bauxite which contains high amounts of aluminium and silica as impurity. The chemical formula of bauxite is\[A{l_2}{O_3}\]. It is reacted with cock in the presence of high temperature and nitrogen gas and there is a formation of aluminium nitride. And the silica is reduced to silicon. The aluminium nitride is reacted with water and there is a formation of water with ammonia as a by-product. And the reaction can be written as,
\[A{l_2}{O_3}.2{H_2}O + {N_2} + 3C\xrightarrow{{2000K}}2AlN + 3CO + 2{H_2}O\]
\[Si{O_2} + 2C \to Si + 2CO\]
\[AlN + 3{H_2}O \to Al{\left( {OH} \right)_3} + N{H_3}\]
We can see that here ammonia is formed as a by-product. Hence, the option (B) is correct.
Serpek’s process is mainly used for the purification of bauxite and there will not be a formation of nitrogen dioxide during the reaction. Hence, the option (C) is incorrect.
Nitric oxide does not form as a by-product in Serpek’s process.
Hence, the option (D) is incorrect.

Note:
We have to know that the Serpek’s process is mainly used for the purification of bauxite which contains high amounts of aluminium and silica as impurity. And it is a reaction of bauxite with cock and there is a formation of aluminium nitride. This aluminium nitride is reacted with water and there is a formation of water with ammonia as a by-product.