Question 18M.3.sl.TZ1.13c.i
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.sl.TZ1.13c.i |
| Level | sl | Paper | 3 | Time zone | TZ1 |
| Command term | Compare and contrast | Question number | c.i | Adapted from | N/A |
Many drugs, including aspirin, penicillin, codeine and taxol, have been modified from compounds that occur naturally.
Compare and contrast the IR spectrum of aspirin with that of salicylic acid, using section 26 of the data booklet.
[2]
One absorption found in both spectra:
Any one of:
1050–1410 cm–1 «C–O in alcohols, esters, ethers»
1700–1750 cm–1 «C=O in carboxylic acids, esters»
2500–3000 cm–1 «O–H in carboxylic acids»
2850–3090 cm–1 «C–H in alkanes, alkenes, arenes»
One absorption found in only one of the spectra:
3200–3600 cm–1 «O–H in alcohols, phenols»
Award [1 max] if candidate states bonds (C=O in both, O–H in salicylic acid only) but doesn’t quote wavelength ranges.
Accept a second/additional absorption at 1700–1750 cm–1 from the C=O in ester.
[2 marks]