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Unformatted text preview: r functionality can have the same Rf value. Because of this…TLC cannot tell us for sure that a compound is identical or not. My lecture slides say otherwise..I know..but I mentioned in class that it wasn’t accurate. I did not, however, annotate this on the slides..so I will accept B or E as answers. 20. You develop a TLC plate and look under the UV lamp, but there were no spots. What is a possible reason? a. The concentration of the sample was too dilute b. The UV light was switched to long‐range c. The compound does not have UV active properties d. You forgot to spot the compound e. All of the above are possible reasons 21. The ability to detect nuclei in the NMR is based on a. Spin b. Bond Order c. Hooke’s Law d. Adsorption e. None of the above 22. How is a signal detected in continuous wave NMR? a. Rf energy is varied while magnetic field is held constant, when energy equals energy of nuclei a resonance occurs b. Rf energy is held constant while magnetic field is varied, whe...
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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