Preparation of graphite:
Graphite can artificially be manufactured by heating coke to about 3000°C in an electric furnace.
Image Source: canmin.geoscienceworld.org
Structure of graphite:
In graphite each carbon atom is covalently bonded to only three neighbouring carbon atoms. The uniplanar layers of six-carbon atoms hexagonally arranged in a benzene ring are held in the crystal by van der Waals’ forces.
Carbon and its compound:
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Of large distances between two successive layers, there is no possibility of bond formation between carbon atoms lying in opposite layers.
Thus the fourth valency in carbon atoms remains free. This causes easy flow of electrons through graphite which thus acts as a good conductor of electricity. The hexagon in graphite is regular, C—C bond length being 1.92 A. The distance between planes is 3.9 A.
Properties:
Chemically graphite is more reactive than diamond. It burns in air at 690°C to carbon dioxide. It is a good conductor of electricity and heat.
Uses:
It is used for electrodes, lead pencils, for making crucibles, for casting of metals.