6.1.5: Reactions and uses of esters

Question 1

Properties of esters

3

Answer 1

sweet smell
polar liquids
low boiling points

Question 2

Uses of esters

5

Answer 2

industrial solvents
plasticiers 
colourings and flavourings
paints
glue

Question 3

Two types of hydrolysis of esters

Answer 3

acid hydrolysis and base hydrolysis

Question 4

Reverse esterification reaction

Answer 4

hydrolysis

base/acid

Question 5

Acid hydrolysis

Answer 5

Splits the ester into a carboxylic acid and an alcohol by refluxing with a dilute acid (HCl/H2SO4)

Question 6

What is necessary in acid hydrolysis reactions

and why

Answer 6

lots of water to push equilibrium to the right

Question 7

Base hydrolysis

Answer 7

Reflux the ester with a dilute alkali (NaOH) to form a carboxylate ion and an alcohol

Question 8

Lipids (animals fats and vegetable oils)

Answer 8

Esters of glycerol and fatty acids

Question 9

Fatty acids are

Answer 9

long chain carboxylic acids

Question 10

Types of fatty acids

2

Answer 10

saturated

unsaturated

Question 11

Hydrolysis of fats and oils

Answer 11

base hydrolysis (NaOH)
form glycerol and a carboxylate ion which combines with Na to form a sodium salt

Question 12

Soap is a type of

Answer 12

sodium salt

Question 13

Glycerol also known as

Answer 13

propane-1,2,3-triol

Question 14

Converting sodium salt back into a long chain carboxylic acids

Answer 14

add an acid such as HCl

Question 15

Biodiesel

Answer 15

vegetable oils react with methanol and a strong alkali catalyst (NaOH or KOH)
to form methyl esters (biodiesel) and glycerol

Question 16

Biodiesel impact on environment

Answer 16

carbon neutral

However energy required to harvest, plant and transport them comes from fossil fuels so overall process isn’t neutral