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- Question
What is the name given to the relaxation process due to an interaction between an excited nucleus and the magnetic fields caused by nuclei in molecules moving around in the sample?
Options- A. Spin - lattice relaxation
- B. Spin - spin relaxation
- C. Spin - spin - spin relaxation
- D. None of these
- Correct Answer
- Spin - lattice relaxation
- 1. An FT-IR instrument record a signal in the
Options- A. time domain
- B. frequency domain
- C. both (a) and (b)
- D. none of these Discuss
- 2. When radiation energy is absorbed by a spin 1/2 nucleus in a magnetic field, what happens?
Options- A. The processional frequency of the nucleus increases
- B. The nucleus spins faster
- C. The angle of precession flips so that the magnetic moment of the nucleus opposes the applied field
- D. none of the above Discuss
- 3. What does the Michelson interferometer do?
Options- A. Split a polychromatic beam of radiation into its component wavelengths
- B. Selectively filter certain wavelengths from a beam of I.R. radiation
- C. Modulate the I.R. signal at a lower frequency, so that it can be observed by a detector
- D. none of the above Discuss
- 4. The frequency of precession, the transition frequency and the Larmor frequency are
Options- A. different terms for the same frequency
- B. same terms for the same frequency
- C. different terms for the different frequency
- D. same terms for the different frequency Discuss
- 5. The sequence of amino acids in proteins can be determined by means of
Options- A. identification of the -NH2 terminal amino acids
- B. identification of the -COOH terminal amino acids
- C. partial cleavage of the original polypeptide into smaller polypeptides
- D. all of the above Discuss
- 6. Why is it advantageous to record many FID signals from the same sample and then add them together?
Options- A. To ensure that all target nuclei in the sample have been excited
- B. To remove inaccuracies caused by fluctuations in the applied magnetic field
- C. To increase sensitivity
- D. None of the above Discuss
- 7. Which of the following gases is unsuitable for use as a GC carrier gas?
Options- A. Nitrogen
- B. Helium
- C. Oxygen
- D. All of the above Discuss
- 8. Which of the following are not used as stationary phases in a GC column?
Options- A. Polysiloxanes
- B. Silica
- C. Cyclodextrins
- D. None are used as stationary phases Discuss
- 9. Which of the following detectors give concentration-dependent signals?
Options- A. Electron-capture detector
- B. Thermal conductivity
- C. Infra-red detector
- D. All of these Discuss
- 10. Headspace analysis is carried out in order to
Options- A. analyse volatile compounds from solid or liquid samples
- B. determine the psychological state of the tutor
- C. analyse the column contents ahead of the sample
- D. determine non-volatiles Discuss
FT IR Spectroscopy problems
Search Results
Correct Answer: time domain
Correct Answer: The angle of precession flips so that the magnetic moment of the nucleus opposes the applied field
Correct Answer: Modulate the I.R. signal at a lower frequency, so that it can be observed by a detector
Correct Answer: different terms for the same frequency
Correct Answer: all of the above
Correct Answer: To increase sensitivity
Correct Answer: Oxygen
Correct Answer: Silica
Correct Answer: All of these
Correct Answer: analyse volatile compounds from solid or liquid samples
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