CAIE A Level Chemistry 9701 · Analytical techniques
The infrared spectra of two organic compounds, A and B, are recorded. The table shows the key absorption bands and their intensities.
| Compound | Absorption bands / cm (appearance) |
|---|---|
| A | 2950 (weak), 3200–3500 (strong, broad), 1050 (strong) |
| B | 2950 (weak), 2720 (weak), 2820 (weak), 1710 (strong) |
Compare the IR spectra of A and B and identify the functional groups present in each compound.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
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