CAIE A Level Chemistry 9701 · Analytical techniques
An unknown compound has the molecular formula . Its infrared spectrum shows a strong, broad absorption between 2500 and 3300 cm⁻¹, a strong absorption at 1710 cm⁻¹, and a strong absorption at 1250 cm⁻¹.
Explain how this spectrum identifies the functional groups present, and state the most likely class of compound.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.