A compound has a carbon-13 NMR spectrum that shows a peak at 75 ppm. What does this indicate about the carbon environment in the compound?

The peak at 75 ppm indicates that the carbon is likely in a carbon environment that is adjacent to electronegative atoms, such as oxygen or nitrogen, or is part of a carbonyl group. This suggests that the carbon is in a functional group that influences its chemical shift. This answer is anchored to NMR spectroscopy (A-level only).

The peak at 75 ppm indicates that the carbon is likely in a carbon environment that is adjacent to electronegative atoms, such as oxygen or nitrogen, or is part of a carbonyl group. This suggests that the carbon is in a functional group that influences its chemical shift. is the best answer because it directly supports the AQA A-Level Chemistry objective to use NMR evidence with other analytical data to determine structures. This reasoning is anchored to NMR spectroscopy (A-level only) in Nuclear magnetic resonance spectroscopy (A-level only), and it separates NMR from similar A-Level ideas rather than relying on a vague recall statement. Other options are weaker if they use the wrong evidence, calculation, mechanism, observation, unit, or conclusion for this subtopic.