Question

What is alumina?
(A) $A{l_2}{O_3}$
(B) $Al{(OH)_3}$
(C) $NaAl{O_2}$
(D) $Al$

Answer 1

Alumina is a white crystalline substance that is produced synthetically. Alumina is generally used as an active raw agent in the production of ceramic products. It is also known for its use as a starting material in the smelting of aluminium metal.

Complete answer:
So, alumina is nothing but an oxide of aluminium i.e. it is an aluminium oxide.
It has a molecular formula $A{l_2}{O_3}$ . So, basically alumina is the aluminium metal in its highest oxidation reaction.
Now, let’s have a brief look at the source and the product of the alumina.
Alumina is generally extracted from its good quality ore Bauxite. This bauxite is commonly found in the topmost layer of the soil of the tropical or subtropical region.
Generally, Alumina is produced from bauxite through Bayer's process.
It is an industrial method to extract aluminium oxide from bauxite.
In this process bauxite is treated with a reagent sodium hydroxide, $(NaOH)$ and then seeded with crystals to produce aluminium hydroxide. Later on, this aluminium hydroxide is heated to remove the water molecules and form the granular or powdery alumina.

Note:
Alumina has some excellent properties which makes it an important material in the industries. Alumina is very hard in nature, sometimes it is used to cut the sharp edged materials. Alumina has a high compressive strength and can withstand a high rate of temperature. It is also well known for its electrical insulating material. Alumina is often also used in cosmetic products like lipsticks. It has several uses as it is the most abundant oxide of aluminium element.