Carboxylic Acids & Derivatives Flashcards
What do esters end in
“-anoate”
Why do esters have a lower boiling point than carboxylic acids and alcohols
Because esters can only form hydrogen bonds with water and not with eachother. But alcohols/carboxylic acids can form H bonds with both
How do you form an ester and what conditions
Esterification:
Carboxylic acid + alcohol -> ester + water
- dynamic equilibrium
- reagent: H2SO4 Catalyst
- condition: heat under reflux
Describe hydrolysis of an ester into a carboxylic acid in the presence of an acid
- reagent - Dilute HCl
- condition - heat under reflux
- reversible reaction
Describe hydrolysis of an ester into a carboxylic acid in the presence of an alkali (saponification)
- reagent - EXCESS dilute NaOH
- condition - heat under reflux
- forms a carboxylate salt
- not reversible
Why is saponification not reversible
Cannot be attacked by weak nucleophiles eg alcohols
What are the 4 common uses of esters
- solvents
- plasticisers
- perfumes
- food flavourings
Why are esters used for perfumes
- Soluble in alcohol
- Non toxic
- Volatile
- Doesn’t react with water
Why can esters be used as solvents
- they’re polar
How can esters be used as plasticisers
- added to pure polymers to make them more flexible and reduces intermolecular forces
What’s propane-1,2,3-triol
Glycerol
Glycerol + fatty acids =?
Esters which make fats and oil
What are fats and oils at room temp and what type of bonds will they have
Fats - higher VDWs so solids (has all single bonds)
Oils - lower VDWs liquids (has double bonds)
How can soap (sodium salt) be made
Hydrolysis of Fats and oils by heating with NaOH
What is biodiesel and how can it be made
It is a mixture of fatty acids made from methyl esters
Made by:
- Oil + methanol
- using KOH catalyst
