Esters
Chemistry: Edexcel IGCSE, topic 15.5.1
Esters
Esters are organic compounds formed by the reaction of an alcohol with a carboxylic acid.
Functional group
- The functional group of esters is -COO.
Naming esters
- There is a standard system for naming esters.
- The first part of the name is formed from the name of the alcohol. This part of the name is the name of the alcohol with ‘yl’ at the end instead of ‘ol’.
- The second part of the name for an ester comes from the carboxylic acid. The name removes the ‘oic’ part and replaces it with the ending ‘oate’.
- E.g ethanol + propanoic acid → ethyl propanoate.
Properties
- Esters are useful because they have strong distinctive ‘fruity’ smells.
- They are volatile, which means they are liquids that become vapours easily. This means their smell can spread easily.
- Esters are often used in perfumes and in food flavourings.
Test yourself on Esters
Which of these are true about esters?
Which of these are true about naming esters?