Esters
Esters are another homologous series of organic compounds. They are sweet-smelling and have a fairly complicated structure for this level of organic chemistry.
Manufacture
An ester is the result of the reaction between a carboxylic acid and alcohol.
Ethyl ethanoate is produced by the reaction of ethanoic acid (the acid) and ethanol (the alcohol).
Ethanoic Acid + Ethanol 
Ethyl Ethanoate + Water
CH3COOH + C2H5OH CH3COOC2H5 + H2O
It has the following structure, note that you can recognize a part resembling ethanoic acid and another ethanol.
Naming esters can be quite hard, however, once you have drawn out the structure it should be easy. The part from the acid ends in -oate (methanoate, ethanoate) and the part from the alcohol is the ethyl group (methyl, ethyl, pentyl etc).
Draw out the structure or better still, use a model set to learn how to draw any ester in an exam.
| Methyl Ethanoate | Butyl Propanoate |
|---|---|
| Ethanoic Acid + Methanol | Propanoic Acid + Butanol |
 |
The combinations are numerous, but hopefully you can see how the pattern works. Using the rules of naming (see above) and the basic rules of organic chemistry nomenclature you should find esters very easy.
Pear Drops
Esters are sweet-smelling liquids and used to flavour foods and sweets. Ethyl ethanoate for example is used in pear drops, because of its distinctive aroma which is similar to pears. And different esters are used as flavourings from honey (methyl phenyl ethanoate) to parsnip (octyl butyrate) to rum (propyl isobutrate).