Class 10 Science

Organic Compounds

These notes are based on the chapter Carbon and its Compounds from class 10 science of NCERT book and CBSE syllabus.

Initially, compounds of carbon could only be obtained from living sources and there was no way of synthesizing them. Hence, carbon compounds are also known as organic compounds. Carbon forms a large number of compounds. So far, formulae of about 3 million carbon compounds are known.

Cause of Large Number of Organic Compounds


formation of chains by carbon atoms

These examples show various possibilities of formation of chain in organic compounds. Carbon can form a linear chain as shown in first figure. Carbon can form a branched chain as shown in second figure. Carbon can also form a cyclic chain as shown in third figure.

Carbon can also form bonds with other types of monovalent atoms, apart from carbon. Carbon can make long chain combining with other atoms also. For example; carbon can form bonds with oxygen, hydrogen, nitrogen, etc.

formation of carbon bond with other atoms radicals

Carbon-carbon bonds are very stable, which makes the compounds of carbon stable.


(Hydrogen + Carbon = Hydrocarbon) Compounds formed because of the combination of hydrogen and carbon are known as hydrocarbons. There are two types of hydrocarbon, viz. saturated hydrocarbon and unsaturated hydrocarbon.

Saturated Hydrocarbons

Hydrocarbons having only single bonds are known as SATURATED HYDROCARBONS. Saturated hydrocarbons are known as ALKANE. These are also known as paraffin. Example: Methane, Ethane, Propane, etc.

Unsaturated hydrocarbon

Unsaturated hydrocarbons are of two types,i.e. Hydrocarbon with double bond and hydrocarbon with triple bond.

Hydrocarbon with double bond

Hydrocarbons having at least one double bond are known as ALKENE. Example: Ethylene, Propylene, Butylene, etc.

Hydrocarbon with triple bond

Hydrocarbons having at least one triple bond are known as ALKYNE. Example: Ethyne, Propyne, Butyne, etc.