Question

What is the formula of Silicon Carbide (Carborundum)?
A. $\text{S}{{\text{i}}_{2}}{{\text{C}}_{2}}$
B. $\text{S}{{\text{i}}_{2}}\text{C}$
C. $\text{SiC}$
D. None of these

Answer 1

Hint: It is an inorganic compound which has a crystal structure like that of diamond and is very hard whose molecular mass is 40.10 g/mol. It is used as abrasive for cutting, grinding and as refractory. This compound was discovered by E.G Acheson and received a patent on it in 1893.

Complete step by step solution:
Silicon Carbide is a synthetic compound comprising silicon and carbon. The chemical formula of Silicon Carbide is SiC. It is a simple compound with the carbon atom attached to silicon through a triple bond, leaving both atoms with a positive and negative charge. However, the bonding between them has a predominantly covalent character, rather than ionic.
Preparation: Silicon carbide is prepared industrially by the Acheson method, in which pure silica sand ($\text{Si}{{\text{O}}_{2}}$) and finely ground coke (carbon) are mixed together and heated to very high temperature in an electric furnace.
$\text{Si}{{\text{O}}_{2}}+3\text{C}\to \text{SiC+2CO}$$\text{Si}{{\text{O}}_{2}}+3\text{C}\to \text{SiC+2CO}$
While attempting to produce artificial diamonds, Acheson heated a mixture of clay and powdered coke in an iron bowl, with the bowl and an ordinary carbon arc-light serving as the electrodes. The new compound, which was obtainable from cheap raw materials and in good yields, soon became an important industrial abrasive.
Silicon carbide is a very stable and chemically inert compound. It is an extremely hard material, with a Mohs hardness rating of 9, close to that of diamond.
Therefore, the correct option is (c) SiC.

Note: Pure SiC is obtained with a density of 3.21g/mL and an extremely high melting point ${{2730}^{\text{o}}}\text{C}$. It is widely used as an abrasive. It is used to make various materials such as sandpapers, grinding wheels, cutting tools, high temperature bricks, heating elements, automobile parts. It is also an important material in the electronics industry and used for making light-emitting diodes (LEDs) and semiconductor devices.