- Carboxylic acids react with alcohols to make esters - Which have fruity smells
- Uses: food products, perfumes, solvents and plasticisers
- They're made by:
1: Heating Under Reflux 2: Distillation
3: Purification 4: Drying
Process One: Heating Under Reflux
Ethanol and Ethanoic Acid are heated under reflux with presence of concentrated Sulfuric Acid.
Reflux is a process of continual evaporation and condensation.
This means the mixture is continually heated and returned to the flask.
Process Two: Distillation
The ester is removed by distillation.
In the distillation process, the liquid that has turned to a gas is removed from the reacting mixture.
Process three: Purification
The distillate is transferred to a Separating funnel where it is purified:
- A solution of Sodium Carbonate is added and the mixture is shaken
- It will react with any remaining acid and extract it into the aquaeous phase
- The aquaeous phase is run off
Process Four: Drying
The product is transferred into a conicle flask
Anhydrous Calcium Chloride is added to the mixture
This removes any remaining water molecules
It is later removed by filtration
- Fats are esters of glycerol and fatty acids
- Living organisms make fats and oils to use as energy
- The difference between animal fats and unsaturated fats are the reactivity and bonds
Unreactive More Reactive
- Exothermic Reactions release energy (heat) so there is a rise in temperature
- They release energy because the products have less enerygy than the reactants did
- Endothermic Reactions are less common than Exothermic Reactions
- They take in energy so they have a temperature decrease
- Bonds need to be broken to start a chemical reaction
- Energy is needed to break bonds
- The amount of energy required to start a reaction is called the ACTIVATION ENERGY
Hydrogen & Bromine
Hydrogen + Bromine = Hydrogen Bromide
H2 + Br2 = 2HBr
H-H + 193 = 627 --> Activation Energy