Uses of esterwes

Question 1

What is the systematic name for glycerol?

Answer 1

propane- 1,2,3-triol

Question 2

What are animal and vergetable oils and fat?

Answer 2

ester of glycerol

Question 3

What is the difference between fats and oils?

Answer 3

oils are liquid and fats are solid at room temperature

Question 4

WHy are fats and oils reffered to as triglycerides?

Answer 4

• contain three molecules of long chain (around 12-18 carbons) carboxylic acids called fatty acids
• since they are based on glycerol, they are referred to as triglycerides

Question 5

What are fats and oils hydrolysed in acid conditions to give?

Answer 5

mixture of glycerol and the compoinent fatty acids

Question 6

How else can they be hydrolysed?

Answer 6

boiling with NaOH

• produces glycerol and a mixture of sodium salts of the three acids which formed part of the ester

Question 7

WHat are the uses of the salts formed

Answer 7

soap can be a mixture containing many different salts

Question 8

Draw the reaction for hydrolysis

Answer 8

Question 9

What are the properties of the sodium salts?

Answer 9

• ionic
• dissociate to from Na+ and RCOO-

Question 10

HOw does thios make the salts useful?

Answer 10

• RCOO- has two distinct end
  
  • long hydrocarbon chain which is non-polar
  • the COO- group which is polar and ionic
• the hydrocarbon will mix with grease, the COO- mixes with water
• tadpole-shaped molecules allow grewas and water to mix and therefore are useful cleaning agents

Question 11

How are esters used in cosmetics and foods?

Answer 11

• sweet smell
• flavourings
• perfumes

Question 12

How is the polar nature of esters useful?

Answer 12

• polar organic compounds dissolve in them
• low boiling points, evaporate from mixture
  
  • good solvents in glue and printing ink