CAIE A Level Chemistry 9701 · Analytical techniques
A compound X has the molecular formula . Its carbon-13 NMR spectrum (proton-decoupled) shows four peaks at chemical shifts of 15, 25, 50 and 80 ppm relative to TMS.
Describe the carbon environments present in X and suggest two possible structures for X that are consistent with this spectrum. Explain your reasoning.
7 marks, so the mark scheme is looking for about 7 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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