State the meaning of the functional group in an organic compound. Write the formula of the functional group present in alcohols, aldehydes, ketones and carboxylic acids.

Functional group is defined as an atom or a group of atoms which makes carbon compounds reactive and also the decides the various properties of the compounds.

The formula for the functional groups are as follows:

1. Alcohol –OH

2. Aldehyde:

3. Ketones:

4. Carboxylic acids