17.3 4 Esters

Question 1

How to name an esters

Answer 1

1. First word comes from alkyl group joined to the O e.g. methyl/propyl /ethyl
2. Second word comes from alkyl joined to the C e.g. methanoate/ethanoate

Question 2

Physical properties

Answer 2

Colourless liquids , relatively low melting and boiling points and are insoluble in water . All hydrogen atoms in molecules are attached to carbon atoms so hydrogen bonding is not possible

Question 3

Ester smells

Answer 3

familar odours of fruits and flowers

present in perfumes , food flavourings,solvents ,anaesthetics and biofuels

Question 4

Hydrolysis in acidic conditions

Answer 4

Warming in water will cause hydrolysis into a carboxylic acid and alcohol
catalyst such a sulfuric acid will speed up
equilibrium

Question 5

Hydrolysis in alkaline solution

Answer 5

disadvantage of using alkali such as aqueous sodium hydroxide is you get a carboxylate salt instead of carboxylic acid
advantage is reaction goes to completion instead of reaching equilibrium
convert salt to carboxylic acid just add dilute acid

Question 6

see

Answer 6

equations in book

Question 7

Saponification

Answer 7

alkaline hydrolysis of esters
soap making
vegetable oils contain large quantities of triglycerides which are triesters hydrolysed to one alcohol and three carboxylic acid
see book

Question 8

difference between soaps and detergents

Answer 8

soaps are made from organic molecules obtained from vegetable and animal sources where as detergents are made from organic molcules obtained from crude oil