Esters

Question 1

how is esterification carried out?

Answer 1

• reaction of an alcohol with a carboxylic acid to form an ester
• reaction of an alcohol with an acid anhydride
• in the presence of an acid catalyst (e.g. concentrated H2SO4)

Question 2

what are the uses of esters?

Answer 2

• sweet smelling liquids
• used as flavouring
• colourless liquid

Question 3

what can esters by hydrolysed by?

Answer 3

• aqueous acid
• aqueous alkali

Question 4

what is acid hydrolysis?

Answer 4

• esters are hydrolysed in hot aqueous acid to form carboxylic acids and alcohols
• this is a reversible reaction

Question 5

how do you carry out acid hydrolysis?

Answer 5

• ester is heated under reflux with dilute aqueous acid
• ester is broken down by water, and the acid acts as a catalyst

Question 6

what is alkaline hyrdolysis?

Answer 6

• ester is hydrolysed in hot aqueous alkali to form carboxylate salts and alcohols
• this reaction is irreversible

Question 7

is both acid and alkaline hydrolysis how is the ester heated?

Answer 7

heated under reflux

Question 8

what would be an observation of an alcohol and carboxylic acid reaction?

Answer 8

• oily layer forms
• sweet/fruity smell