Carboxylic acid 26.3

Question 1

Are carboxylic acids soluble in water?

Answer 1

Carboxylic acids with up to 4 carbons are soluble in water

Question 2

Why are long chain carboxylic acids insoluble?

Answer 2

As number of C atoms increases, the solubility decreases as the non-polar carbon chain has a greater effect on overall polarity of the molecule

Question 3

Which bonds are polar in carboxylic acids?

Answer 3

C=O and O—H

Question 4

How strong are carboxylic acids?

Answer 4

They are classified as weak acids

When dissolved in water they partly dissociate

Question 5

What type of reactions to carboxylic acids undergo?

Answer 5

Redox reactions with metals

Neutralisation reaction with bases

Question 6

What is the carboxylic acid ion called?

Answer 6

The carboxylate ion
E.g.
(Sodium carboxylate)

Question 7

What is produced from carboxylic acid + metal ?

And what would be observed

Answer 7

1. Hydrogen gas and salt

2. Effervescence of H2 gas and the metal disappearing

Question 8

Carboxylic acid + metal oxide =

Answer 8

Salt + water

Question 9

Carboxylic acid + alkali =

Answer 9

Salt + water

Question 10

Carboxylic acid + carbonate =

Answer 10

Water + carbon dioxide gas

Question 11

How to test for the carboxyl group?

Answer 11

As CB acids react with carbonates to produce CO2 chemists can use this to distinguish carboxylic acids from any other compound.
As carboxylic acids only common organic compound sufficiently acidic to react with carbonates.