CAIE A Level Chemistry 9701 · Analytical techniques
A student prepares a liquid ester by reacting an alcohol with an acid. The carbon-13 NMR spectrum of the ester shows four peaks, with chemical shifts of approximately 14, 22, 60 and 170 ppm.
Describe what can be deduced from this spectrum about the different environments of the carbon atoms in the ester, and suggest a possible structure for the ester.
6 marks, so the mark scheme is looking for about 6 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.
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