Question

How is graphite prepared?

Answer 1

• Graphite is an allotropic form of Carbon that exists in the crystalline structure.
• The property of an element due to which it exists in different physical forms which have identical chemical properties but different physical properties is called as allotropy.
• The different physical forms of that element are called as allotropes.
• Example: Carbon is an element that shows the property of allotropy because it exists in different physical forms that have identical chemical properties but different physical properties. Diamond and graphite are allotropes of Carbon.
• Graphite can be prepared artificially in an electric furnace at a temperature of about 3000 degrees in two steps given below.

Step-1: Reaction of Silicon dioxide (from sand) with powdered coke at 3000° C.

Carbon monoxide and Silicon carbide are obtained.

$$\begin{gathered} {\mathrm{SiO}}_2\left(\mathrm{s}\right)+3\mathrm{C}\left(\mathrm{s}\right)\stackrel{3000°\mathrm{C}}{\to }2\mathrm{CO}\left(\mathrm{g}\right)+\mathrm{SiC}\left(\mathrm{s}\right) \\ (\mathrm{Silicon}\mathrm{dioxide})\left(\mathrm{Carbon}\right)(\mathrm{Carbon}\mathrm{mono}-\mathrm{oxide})(\mathrm{Silicon}\mathrm{carbide}) \\ (\mathrm{from}\mathrm{sand})(\mathrm{from}\mathrm{coke}) \end{gathered}$$

Step 2: Reaction of Silicon carbide obtained above reacts with Ferric oxide (Fe₂O₃)

Silicon (Si) and Carbon (C) in the form graphite are formed.

$$\begin{gathered} \mathrm{SiC}\left(\mathrm{s}\right)\stackrel{\mathrm{Ferric}\mathrm{oxide}}{\to }\mathrm{Si}\left(\mathrm{s}\right)+\mathrm{C}\left(\mathrm{s}\right) \\ (\mathrm{Silicon}\mathrm{carbide})\left(\mathrm{Silicon}\right)\left(\mathrm{Carbon}\right) \end{gathered}$$