Atom or group of atoms which determines the chemical properties of an organic compound is called functional group. Example: –COOR is the functional group of ester. An organic compound may contain one or more functional group. In this case, the naming of organic compound is made according to priority order.
The priority order of the functional group is given below:
Sulphonic acid > Carboxylic acid >Acid Anhydride > Ester > Acid chloride > Amide > Aldehyde > Nitrile > Ketone > Alcohol > Amines > Ethers > Alkenes > Alkynes
Significance of functional group:
- Functional group denotes the naming of organic compounds.
- Functional group specifies the classes of organic compounds.
- Functional group denotes the reactivity of organic compounds.