Learning focus
Develop accurate organic nomenclature, connect functional groups to reactions, draw structural and polymer formulae, interpret industrial processes and apply evidence to unfamiliar compounds.
Neutralisation with bases
Carboxylic acid + base -> carboxylate salt + water. CH3COOH + NaOH -> CH3COONa + H2O. The ionic idea is transfer of a proton to OH-.
Reaction with carbonates
Carboxylic acid + carbonate -> carboxylate salt + carbon dioxide + water. Two acid molecules are required per carbonate ion.
Example equation
2CH3COOH + Na2CO3 -> 2CH3COONa + CO2 + H2O. Effervescence occurs and CO2 turns limewater milky.
Naming and formulae
Use the cation name followed by alkanoate. Calcium propanoate contains Ca2+ and two propanoate ions. Formula construction must respect ion charges.
High-value recall and connections
Essential recall: What products form with a base? A carboxylate salt and water. What extra products form with a carbonate? Carbon dioxide and water. How is CO2 tested? It turns limewater milky. Practical connection: Add small carbonate portions to ethanoic acid, collect the gas and apply the limewater test. Record reagent, observation and inference separately. Examination connection: For a carbonate, include both CO2 and H2O among the products.
Practical or data skill
Add small carbonate portions to ethanoic acid, collect the gas and apply the limewater test. Record reagent, observation and inference separately.
Examination tip
For a carbonate, include both CO2 and H2O among the products.
Review questions and suggested answers
Question 1
What products form with a base?
Suggested answer
A carboxylate salt and water.
Question 2
What extra products form with a carbonate?
Suggested answer
Carbon dioxide and water.
Question 3
How is CO2 tested?
Suggested answer
It turns limewater milky.
