A radio-frequency pulse creates a spin-flip transition between energy levels in this technique. For 10 points each:
[10e] Name this form of spectroscopy that applies an external magnetic field to analyze nuclei.
ANSWER: NMR spectroscopy [or nuclear magnetic resonance spectroscopy]
[10m] When analyzing compounds in NMR, hydroxyl and amine protons have a notoriously broad range for this value. This quantity, the ratio of the change in frequency to the reference frequency, is usually given in ppm.
ANSWER: chemical shift [prompt on delta; prompt on shift]
[10h] This is the simplest compound added to a sample in proton NMR in order to isolate hydroxyl or amine peaks. Exchangeable labile protons disappear following the addition of this compound in its namesake “shake.”
ANSWER: heavy water [or D2O; accept heavy water shake; reject “water” or “H2O”]
<Chemistry>