In the 1H NMR spectrum of aspirin, you would expect to see four distinct signals. Here are the approximate chemical shifts and the protons they correspond to:
- 2.3 ppm: This signal corresponds to the methyl group (CH3) attached to the carbonyl group.
- 7.2-7.4 ppm: These signals correspond to the aromatic protons on the benzene ring. There are four aromatic protons, but due to symmetry, they appear as two sets of doublets.
- 10-12 ppm: This signal corresponds to the carboxylic acid proton (COOH).
- 3.3-3.5 ppm: This signal corresponds to the proton on the hydroxyl group (OH) attached to the benzene ring.
These chemical shifts are approximate and can vary slightly depending on the solvent and the specific conditions of the NMR experiment.