Esters

Question 1

Functional group of esters

Answer 1

R1COOR2

Question 2

Nomenclature - esters
Ending and prefix

Where does the alcohol go and where does the carboxylic acid go

Answer 2

-anoate ~ carboxylic acid
-thyl ~ alcohol

Example:
Methyl ethanoate

Question 3

Physical properties of esters:
- colour
- melting and boiling points
- solubility
- hydrogen bonding and why
- smells and importance

Answer 3

• Colourless liquids
• Low melting and boiling points
• insoluble in water
• cannot form hydrogen bonds as all hydrogen atoms are bonded to a carbon atom
• distinctive pleasant smells, usually of flowers and fruits. Different for each ester so can be used for identification

Question 4

Making esters equation and conditions
(Already covered)

Answer 4

R1COOH + R2OH <—> R1COOR2 + H2O
Acidic catalyst

Question 5

Reactions Esters do - list

Answer 5

Acidic conditions hydrolysis - already covered
Alkali conditions hydrolysis - already covered

Question 6

Acidic conditions ester hydrolysis equation (already covered in producing carboxylic acids)
And conditions

Answer 6

R1COOR2 + H2O <—> R1COOH + R2OH
Dilute HCl or H2SO4 as a catalyst

Question 7

Alkali conditions ester hydrolysis equation
What is different about this reaction compared to acidic conditions

Answer 7

R1COOR2 + NaOH —> R1COO- Na+ + R2OH
It is irreversible

Question 8

Conditions for alkali conditions of ester hydrolysis
What is the product

Answer 8

Aqueous conditions under reflux
Carboxylate