Actual 2024 AQA A-LEVEL CHEMISTRY 7405/3 Paper 3 Merged Question Paper + Mark
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IB/M/Jun24/7405/3
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Answer all questions in this section.
0 1 The structure of 2-hydroxybenzenecarboxylic acid is shown.
0 1 . 1 Give the equation for the reaction of 2-hydroxybenzenecarboxylic acid with methanol.
In your equation, include the skeletal formula of the organic product.
[2 marks]
Aspirin is produced from 2-hydroxybenzenecarboxylic acid by reaction with
ethanoic anhydride in the presence of concentrated phosphoric acid.
Method
1. Add 2-hydroxybenzenecarboxylic acid to a conical flask.
2. Add excess ethanoic anhydride.
3. Add a few drops of concentrated phosphoric acid.
4. Heat the flask to 85 °C for 10 minutes.
5. Cool the flask and pour the contents into 150 cm3 of cold water.
6. Filter and wash the impure solid aspirin.
7. Recrystallise the aspirin using a 50:50 mixture of water and ethanol.
8. Check the purity of the aspirin.
0 1 . 2 Aspirin can also be produced by reacting 2-hydroxybenzenecarboxylic acid with
ethanoyl chloride.
State why ethanoic anhydride is preferred to ethanoyl chloride for this preparation.