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Unformatted text preview: n energy equals energy of nuclei a resonance occurs c. All nuclei are excited at once and one sin wave is converted using Fourier transform d. Nuclei are excited and their relaxation time calculated e. None of the above 23. The scale of the NMR is in parts per million (ppm). This scale is used because a. It represents the concentration of the NMR sample in solution b. It represents the concentration of nuclei in the excited state vs the ground state c. The chemical shifts of signals would be the same no matter what NMR you use d. Using a scale in Hz would be confusing e. None of the above 24. Different nuclei show up at different places on the NMR scale due to shielding. What statement below is true regarding shielding a. The more upfield the signal, the more deshielded b. Signals downfield are more electron rich c. The energy required to enter the nucleus with energy is lower for shielded nuclei d. Shielded nuclei are more electron rich e. None of the above 25. Which of the following can be used as an internal standa...
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This note was uploaded on 04/23/2012 for the course CHEM 6al taught by Professor Pettus during the Spring '08 term at UCSB.
- Spring '08