A curriculum resource for post-16 chemistry and science courses

This resource contains eight free-standing activities that can be used singly or as a coherent package in a wide range of teaching and learning situations for both academic and vocational courses. It is aimed at post-16 chemistry and science students and their teachers.

Contents

Background information

1. The aspirin story

Experimental and investigative section

2. The preparation of 2-hydroxybenzoic acid

3. The preparation of aspirin

4. Purifying by recrystallisation

5. The melting point of aspirin

6. Using thin-layer chromatography to investigate the reaction

7. The solubility of aspirin

8. Thin-layer chromatography and analgesics

How to use this resource

Each resource is organised into two main downloads - a student activity and a guide for teachers and technicians with equipment lists and answers. Within the student activities there are both written and practical tasks. The practical tasks are both preparative/analytical and problem-solving. 

Nomenclature

For ease of use some traditional names are retained for chemicals throughout these resources. Below are listed the traditional names against the systematic names that are commonly used in post-16 chemistry courses in the UK.

 Traditional name/trade name Systematic name
 Acetanilide  N-Phenylethanamide
 Aspirin  2-Ethanoyloxybenzenecaboxylic acid
Caffeine   3,7-Dihydro-1,3,7-trimethyl-1 H- purine-2,6-dione
Ibuprofen   (±)-2-(4-Isobutylphenyl)propionic acid
Methly salicylate   Methyl 2-hydroxybenzoate
Paracetamol   N-(4-Hydroxyphenyl)ethanamide
Phenacetin   N-(4-Ethoxyphenyl)ethanamide
Salicylic acid   2-Hydroxybenzoic acid
Sodium salicylate   Sodium-2-hydroxybenzoate

Health and safety

Teachers must consult their employer’s risk assessments before commencing any practical activity. It is good practice to encourage students to do so also. However, this does not absolve teachers from their responsibility to check students’ plans and supervise the activity. Eye protection and other appropriate protective equipment should be worn for all the experiments in this booklet. 

Dichloromethane is harmful by inhalation. Avoid breathing vapour and avoid contact with skin and eyes.

Ethanoic anhydride is flammable and causes burns.

Ethanol is flammable.

Ethyl ethanoate is volatile, highly flammable and the vapour may irritate the eyes and respiratory system. Avoid breathing the vapour and avoid contact with the eyes. Keep away from flames.

Hydrochloric acid can cause burns. It gives off an irritating vapour that can damage the eyes and lungs.

2-Hydroxybenzoic acid (salicylic acid) is harmful by ingestion and is irritating to the skin and eyes.

Phenol is toxic by ingestion and skin absorption. It can cause severe burns. Take care when removing phenol from the bottle because the colid crystals can be hard to break up. Wear rubber gloves and a face mask.

Phosphoric acid is irritating to the eyes and causes burns.

Sodium hydroxide can cause severe burns to the skin and is dangerous to the eyes.

Short wave UV may cause skin cancer and eye damage. Do not observe directly. The viewer should be screened from direct radiation.

Further information can be obtained from CLEAPSS or SSERC.

More resources

Additional information

Compiled by David Lewis. Edited by Colin Osborne and Maria Pack. Designed by Imogen Bertin and Sara Roberts.

First published by the Royal Society of Chemistry in 1998
Second edition published by the Royal Society of Chemistry in 2003

Optimised and partially updated for online publication in 2023

Aspirin book