C3.6 Carboxylic acids and esters

Question 1

What are the names of the first three carboxylic acids?

Answer 1

Methanoic acid
Ethanoic acid
Propanoic acid

Question 2

What is the functional group of carboxylic acids?

Answer 2

–COOH

Question 3

What happens when carboxylic acids:

1) are put in water (2 things)
2) come into contact with carbonates
3) come into contact with alcohols

Answer 3

1) They dissolve, but don’t ionise completely (so they’re weak acids)
2) React to produce carbon dioxide
3) React with alcohols (with an acid catalyst) to produce esters

Question 4

Does an aqueous solution of a weak acid have a LOWER pH value than an aqueous solution of a strong acid with the same concentration?

Answer 4

No, an aq solution of a weak acid has a higher pH than an aq solution of a strong acid of the same concentration

Question 5

What is ethyl ethanoate produced from?

Answer 5

Ethanol and ethanoic acid

Question 6

What is the functional group of esters?

Answer 6

–COO–

Question 7

Give 2 features of esters and one use

Answer 7

• Volatile
• Have a distinctive smell
• Used as flavourings and perfume

Question 8

An aqueous solution of a weak acid has a higher pH value than…

Answer 8

…an aqueous solution of a strong acid with the same concentration