7.3.2 Esters Flashcards
1
Q
Naming Esters
A
2
Q
Uses of Esters
A
- Fragrances (fruity smell)
- Flavourings
- Plasticisers (increase flexibility of polymers, penetrates layers between polymer chains, reduces polar bonds by increasing distance between them, allowing chains to slide over each other)
- Solvents (cheap, low volatility, low toxicity)
3
Q
What esters are naturally occurring?
A
- Triglycerides in animal fat and olive oil
- 1 glycerol molecule and 3 fatty acids
4
Q
How can esters be used to test for alcohols?
A
- Unknown substance warmed with carboxylic acid in presence of concentrated sulphuric acid
- Excess acid neutralised by adding warm aqueous sodium carbonate
- Pungent vinegary smell should go away
- If remaining mixture has sweet smell, it is an ester, proving presence of an alcohol
- Warm solution causes ester to evaporate so sweet smell is easily detected