CAIE A Level Chemistry 9701 · Analytical techniques
A student records an infrared spectrum of a colourless liquid with molecular formula . The spectrum shows a sharp, strong absorption at 2250 cm and a broad absorption between 2500 and 3300 cm. No other significant absorptions are present.
Explain how this spectrum allows the student to identify the functional group present in the molecule, and state which functional group this is.
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.
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.
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