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General Equation: Carboxylic Acid+Alcohol→Ester+Water
Example Reaction:
Ethanoic Acid + Ethanol → Ethyl Ethanoate + Water
CH3COOH+C2H5OH→CH3COOC2H5+H2O
Catalyst: Concentrated sulfuric acid (H₂SO₄) is used to speed up the reaction and shift the
equilibrium towards ester formation.
3. Properties of Esters
Physical Properties:
Esters are generally colorless, volatile liquids with distinctive fruity or floral smells.
They are typically insoluble in water due to their lack of hydrogen bonding capability but are
soluble in organic solvents.
Boiling Points: Esters have lower boiling points than the corresponding acids due to the absence of
hydrogen bonds.
4. Uses of Esters
Esters are used for their pleasant odors and flavors in perfumes, foods, and drinks.
Some esters (like ethyl ethanoate) are used as solvents in products like nail polish remover and
paints.
Esters are used as plasticizers to make plastics like PVC flexible and durable.
: Esters are found in some drugs due to their ability to be hydrolyzed by enzymes in the body.
Polymers
- Polymers are large molecules formed by linking 50 or more monomers.
- Each repeat unit is connected by covalent bonds.
- Examples of polymers include PVC and nylon.
Formation of Poly(ethene) from Ethene
- Poly(ethene) is formed by the addition polymerisation of ethene monomers.
- Addition polymerisation involves the joining of multiple monomers to form a long-chain
polymer.
- In ethene, the C=C double bond breaks, allowing the monomers to join and form poly(ethene).