Carboxylic Acid

Question 1

State the functional group in a carboxylic acid

Answer 1

Carboxyl (-COOH) functional group. (Exam tip - watch if a question asks you to name or identify the functional group).

Question 2

Name and draw the first 8 carboxylic acids

Answer 2

Methanoic acid- HCOOH
Ethanolic acid- CH3COOH

Question 3

State the reactions that carboxylic acids can have with bases

Answer 3

When reacted with bases, carboxylic acid takes part in a neutralisation reaction, producing a salt and water.

a metal oxide + a carboxylic acid → a salt + water
metal hydroxide + a carboxylic acid → a salt + water
metal carbonate + a carboxylic acid → a salt + water + carbon dioxide
(When long chained fatty acids are used, soap is produced).

Question 4

Name the salt produced from the reactions of carboxylic acids with bases

Answer 4

he name of a salt depends on the acid and alkali in the neutralisation reaction.

Salts have 2 parts to their name; the first part of the name is the metal from the alkali:

Sodium hydroxide - sodium …
Potassium carbonate - potassium …
The second part comes from the acid:

Hydrochloric acid - … chloride
Sulfuric acid - … sulphate
Nitric acid - … nitrate
For example:

Calcium hydroxide + sulfuric acid –> calcium sulphate + water