Describe6 marksChallenge
Tetramethylsilane, , is added to the sample when a proton NMR spectrum is obtained, and its signal is assigned a chemical shift of 0 ppm.
Describe the reasons for using TMS as the standard for chemical shift measurements.
CAIE A Level Chemistry 9701 · Analytical techniques
Analytical techniques: describe question
How this question is marked
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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