CAIE A Level Chemistry 9701 · Analytical techniques
A student records the infrared spectrum of a colourless liquid with the molecular formula .
The spectrum shows a strong, broad absorption between 3230 and 3550 cm and a strong absorption at 1050 cm. No absorption is seen in the region 1620–1680 cm or 2500–3300 cm.
Describe what these absorptions indicate about the functional groups present in the molecule, and deduce the functional group of the 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.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.