Zusammenfassung der Ressource
ESTERS
- Definition
- non-hydrocarbon
organic
compounds
containing carbon,
hydrogen and
oxygen
- General formula
- CmH2m +
1COOCnH2n
where m = 0, 1,
2, 3 n = 1, 2, 3
- Functional group
- Preparation of ester in laboratory
(estrification)
- Esters are produced when carboxylic acid reacts with
alcohol in the presence of concentrated sulphuric acid
as a catalyst
- The concentrated sulphuric acid acts as
- 1-a drying agent to absorb the water that is produced a
2-as catalyst
- The reactant mixture needs to be heated under reflux.
- General chemical equation for estrification
- CnH2n+1COOH + CmH2m+1OH –>
CnH2n+1COOCmH2m+1 + H2O
- Properties of
esters
- Low boiling point
- Fragrant smell (fruity smell)
- Insoluble in water
- Volatile ( substance that vaporizes
readily )
- Colourless liquid
- Less dense than water
- Soluble in organic solvents
- Natural sources
- Found naturally in plants
- Jasmine-benzyl ethanoate
- Pear-propyl ethanoate
- Kiwi-methyl benzoate
- Uses in daily life
- Food flavourings-cakes,ice cream
- Make cosmetics-perfumes
- As fragrance-soaps,detergents
- Make medicines-asthma,leprosy
- Preparing of Propyl Ethanoate (ester) in
Laboratory
- Propyl ethanoate, CH3COOC2H5 can be prepared in the
laboratory by heating a mixture of propanoic acid and
ethanol, with concentrated sulphuric acid under reflux.
- mixture is heated under reflux to prevent the
alcohol and propyl ethanoate to evaporate and
escape to the surrounding.
- mixture is heated in a water bath: to maintain
temperature so that the temperature is not too
high, to ensure uniform heating
- Naming esters