The compounds having same molecular formula but different structural formula are called as isomers and this phenomena is called as Isomerism.
Types of Isomerism:-
(i) Structural isomerism
1. Chain
2. Position
3. Functional
4. Metamerism
5. Tautomerism
(ii) Stereo isomerism
1. Geometrical
2. Optical
Structural Isomerism
The different type of Structural Isomerism is defined below
CHAIN ISOMERISM
Isomers having same molecular formula but different carbon skeletons.
POSITION ISOMERS
Isomers having different position of functional group.
The molecular formula $C_3H_8O$ represents two alcohols:
FUNCTIONAL ISOMERS
Isomers, having same molecular formula but different functional groups.
Aldehyde & Ketone
(RCHO) (RCOR)
For example, the molecular formula $C_3H_6O$ represents an aldehyde and a ketone
METAMERIC ISOMERS
When Ethers have different alkyl groups, such isomers are known as Metameric isomers.
For example, $C_4H_{10}O$ represents methoxypropane ($CH_3OC_3H_7$) and ethoxyethane ($C_2H_5OC_2H_5$ ).
Stereo isomerism
The compounds that have the same constitution and sequence of covalent bonds but differ in relative positions of their atoms or groups in space are called stereoisomers.
