JEE Main and JEE Advanced Syllabus of Hydrocarbons
What are hydrocarbons?
he term ‘hydrocarbon’ is self –explanatory which refers to the compounds formed by combination of carbon and hydrogen only. Hydrocarbons have very important role in our daily life. The Vegetable oil which is part of our food and also the gasoline which we use to run our vehicles is hydrocarbons. Hydrocarbons are the source of energy. The oil, ghee & butter are the hydrocarbon which are part of our diet and provide our body with energy required to perform various physical and biological functions.
LPG, CNG, LNG , Petrol, Diesel and Kerosene oil are the hydrocarbons which are used as fuels for automobiles and domestic uses. LPG is the abbreviated form of liquified petroleum gas, LNG is the abbreviated form of liquified natural gas whereas CNG stands for compressed natural gas. Petrol, diesel and kerosene oil are obtained by the fractional distillation of petroleum found under the earth’s crust while coal gas is obtained by the destructive distillation of coal.
Hydrocarbons are also used for manufacture of polymers like polythene, polypropene, polystyrene etc and also as solvents for paints. They are also used as the starting materials for manufacture of many dyes and drugs.
Classification of Hydrocarbons
Hydrocarbons are broadly divided into aliphatic hydrocarbons and aromatic hydrocarbons. Aromatic hydrocarbons or arenes are the cyclic hydrocarbons with alternating double and single bonds betweeen carbon atoms. Benzene is an example of aromatic hydrocarbon.
Aliphatic hydrocarbons can further be divided into saturated hydraocarbons or alkane and unsaturated hydrocarbons. Saturated hydrocarbons cotain only single bonds throughout the length of carbon chain.
Unsaturated hydrocarbons contain one or more multiple bonds i.e double or triple bond, between the carbon atoms anywhere throughout the carbon chain. Unsaturated hydrocarbons with double bonds between the carbon atoms are called alkenes while those with triple bonds are called alkynes.
There is another class of aliphatic hydrocarbons called alicyclic hydrocarbons. These hydrocarbons are present in the form of rings.