Alcohols, Carboxylic Acids and Esters

Question 1

What functional group do alcohols contain?

Answer 1

• OH
  e. g. CH3CH2OH:

⠀⠀ H   H
⠀⠀  I⠀⠀I
H - C - C - O - H
⠀⠀  I⠀⠀I
⠀⠀ H   H

Question 2

What are the properties of methanol, ethanol and propanol?

Answer 2

dissolve in water to form a neutral solution

react with sodium to produce hydrogen

burn in air

used as fuel and solvents, ethanol is the main alcohol in alcoholic drinks

Question 3

How is ethanoic acid produced?

Answer 3

oxidation of ethanol by chemical oxidising agents or microbial action

ethanoic acid is the main acid in vinegar

Question 4

What functional group do carboxylic acid contain?

Answer 4

-COOH

ethanoic acid is a member of the carboxylic acids

e.g. CH3COOH
⠀⠀ H
⠀⠀ I     
H - C - C = O
⠀⠀  I⠀⠀I
⠀⠀ H   O - H

Question 5

What are the properties of carboxylic acids?

Answer 5

dissolve in water to produce acidic solution

react with carbonate to produce carbon dioxide

do not ionise completely when dissolved in water, so are weak acids

aqueous solutions of weak acids have a higher pH value than aqueous solutions of strong acids with the same concentration

Question 6

How are esters formed and what functional group do they have?

Answer 6

carboxylic acids react with alcohol in the presence of an acid catalyst to produce esters

Ethyl ethanoate is the ester produced from ethanol and ethanoic acid

Esters have the functional group –COO–

Question 7

What are the uses of esters?

Answer 7

they are volatile with distinctive smells, so they are used as flavourings and perfumes