Esters

Question 1

What is the functional group of an ester?

Answer 1

COO

Question 2

What reacts to produce ethyl ethanoate?

Answer 2

Ethanol and ethanoic acid in the presence of an (sulfuric) acid catalyst

Question 3

Describe esters

Answer 3

Volatile compounds with distinctive smells

Question 4

What are esters used for?

Answer 4

Food flavorings and in perfumes

Question 5

How do you prepare an ester?

Answer 5

• Must be done in a fume cupboard as the vapor is toxic
• Must NOT be heated with a Bunsen Burner as the reaction mixture is flammable
  1. Put 1cm cubed of pure (concentrated) ethanoic acid and 1cm cubed of ethanol into a boiling tube
  2. Mix well and carefully add a few drops of concentrated sulfuric acid
  3. Place the boiling tube in a water bath at 80 degrees c for 5 minutes
  4. Pour the resulting reaction mixture containing sodium carbonate solution in order to neutralise any excess carboxylic acid
• Ethanol and ethanoic acid are soluble in water and any excess will dissolve in the sodium carbonate solution. The ester is not very soluble in water and will float to the top.