Ester
- Esters are non-hydrocarbon organic compounds containing carbon, hydrogen and oxygen.
- It is formed when a carboxylic acid reacts with an alcohol.
General Formula:
CmH2m + 1COOCnH2n + 1
where
m = 0, 1, 2, 3
n = 1, 2, 3
Example
Ester | Formula |
Methyl methanoate (m=0, n=1) | HCOOCH3 |
Ethyl methanoate (m=1, n=1) | CH3COOCH3 |
Ethyl ethanoate (m=1, n=2) | CH3COOC2H5 |
Propylethanoate (m=2, n=2) | C2H5COO C2H5 |
Functional group:
Formation:
- Esters are produced when carboxylic acid reacts with alcohol in the presence of concentrated sulphuric acid as a catalyst.
- This reaction is called the esterification reaction.
Physical Properties of Ester
- Ester has the following properties:
- having fragrant similar to fruits
- insoluble in water but soluble in organic solvent
- low boiling point
- less dense than water
- colourless liquid
- volatile
- Ester can be found naturally in plants.
Uses of Ester in Daily Life
- As food flavourings
- as a fragrant in soap and detergent
- To make cosmetics (perfumes)
- To make medicine