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Klein, Organic Chemistry 3e
Chapter 15
1. NMR is an abbreviation for ____________ ____________ __________.
Answer: nuclear magnetic resonance
Learning Objective: 15.1 Describe the interaction between electromagnetic radiation
and atomic nuclei in a magnetic field that makes NMR spectroscopy possible
Difficulty: Easy
2. List the most common nuclei that are used in NMR.
Answer: 1H and 13C
Learning Objective: 15.1 Describe the interaction between electromagnetic radiation
and atomic nuclei in a magnetic field that makes NMR spectroscopy possible
Difficulty: Easy
3. Identify the nuclei that cannot be analyzed by NMR.
A. 15N
B. 14C
C. 19F
D. 31P
E. 1H
Answer: B
Learning Objective: 15.1 Describe the interaction between electromagnetic radiation
and atomic nuclei in a magnetic field that makes NMR spectroscopy possible
Difficulty: Easy
4. Which of the following nuclei cannot be analyzed by an NMR spectrometer?
A. nucleus with odd number of protons & odd number of neutrons
B. nucleus with odd number of protons &even number of neutrons
C. nucleus with even number of protons & odd number of neutrons
D. nucleus with even number of protons & even number of neutrons
E. none of these
Answer: D
Learning Objective: 15.1 Describe the interaction between electromagnetic radiation
and atomic nuclei in a magnetic field that makes NMR spectroscopy possible
Difficulty: Easy
5. How many nuclear spin states are possible for the 1H nucleus?
A. 1
B. 2
C. 4
D. 5
E. none of these
Answer: B
Learning Objective: 15.1 Describe the interaction between electromagnetic radiation
and atomic nuclei in a magnetic field that makes NMR spectroscopy possible
Difficulty: Easy
6. Which of the following electromagnetic radiation is used in NMR spectroscopy?
A. UV
B. IR
C. visible
D. γ-rays
E. radio wave
Answer: E
Learning Objective: 15.1 Describe the interaction between electromagnetic radiation
and atomic nuclei in a magnetic field that makes NMR spectroscopy possible
Difficulty: Easy
7. _______ protons experience a net magnetic field strength that is smaller than the
applied magnetic field.
A. Deshielded
B. Shielded
C. Paramagnetic
D. Diamagnetic
E. none of these
Answer: B
Learning Objective: 15.1 Describe the interaction between electromagnetic radiation
and atomic nuclei in a magnetic field that makes NMR spectroscopy possible
Difficulty: Medium
8. _______ protons experience a net magnetic field strength that is higher than the
_____ protons.
A. Deshielded, shielded
B. Shielded, deshielded
C. Paramagnetic, diamagnetic
D. Shielded, diamagnetic
E. none of these
Answer: A
Learning Objective: 15.1 Describe the interaction between electromagnetic radiation
and atomic nuclei in a magnetic field that makes NMR spectroscopy possible
Difficulty: Medium
9. Which of the following is true about the relationship between the energy gap (∆E)
between the spin states for a 1H nucleus and the strength of the external
magnetic field?
A. they are inversely proportional
B. they are directly proportional
C. there is no relationship
D. the magnetic field is slightly less
E. none of these
Answer: B
Learning Objective: 15.2 Describe how NMR spectrometers work and the process of
preparing a sample for NMR spectral analysis
Difficulty: Medium
10. The strength of the magnetic field is a determining factor for the range of
_______that must be used for NMR spectrometer.
A. temperature
B. frequencies
C. tesla
D. spin states
D. none of these
Answer: B
Learning Objective: 15.2 Describe how NMR spectrometers work and the process of
preparing a sample for NMR spectral analysis
Difficulty: Medium
11. Which of the following is not a common solvent used for acquiring a 1H NMR
spectrum?
A. CDCl3
B. CCl4
C. CD3CN
D. CH3OH
E. D2O
Answer: D
Learning Objective: 15.2 Describe how NMR spectrometers work and the process of
preparing a sample for NMR spectral analysis
Difficulty: Easy
12. Which of the following is true about the number of signals in a 1H NMR
spectrum?
A. it indicates the number of neighboring protons
B. it indicates the electronic environment of neighboring protons
C. it indicates the number of different kinds of protons
D. it indicates the electronic environment of absorbing protons
E. it indicates the number of protons in the signal
Answer: C
Learning Objective: 15.3 State the significance of the number of signals, along with their
locations, areas, and shapes, in am NMR spectrum
Difficulty: Easy
13. Which of the following is true about the location of signals in a 1H NMR
spectrum?
A. it indicates the number of neighboring protons
B. it indicates the electronic environment of neighboring protons
C. it indicates the number of different protons
D. it indicates the electronic environment of absorbing protons
E. it indicates the number of protons in the signal
Answer: D
Learning Objective: 15.3 State the significance of the number of signals, along with their
locations, areas, and shapes, in am NMR spectrum
Difficulty: Easy
14. Which of the following is true about the area under each signal in a 1H NMR
spectrum?
A. it indicates the number of neighboring protons
B. it indicates the electronic environment of neighboring protons
C. it indicates the number of different protons
D. it indicates the electronic environment of absorbing protons
E. it indicates the relative number of protons in the signal
Answer: E
Learning Objective: 15.3 State the significance of the number of signals, along with their
locations, areas, and shapes, in am NMR spectrum
Difficulty: Easy
15. Which of the following is true about the shape (multiplicity) of the signal in a 1H
NMR spectrum?
A. it indicates the number of neighboring protons
B. it indicates the electronic environment of neighboring protons
C. it indicates the number of different protons
D. it indicates the electronic environment of absorbing protons
E. it indicates the number of protons in the signal
Answer: A
Learning Objective: 15.3 State the significance of the number of signals, along with their
locations, areas, and shapes, in am NMR spectrum
Difficulty: Easy
16. In an NMR spectrometer, the receiver coil records a complex signal, called a
________________, which is converted into a spectrum via a mathematical
technique called a ____________________.
Answer: free induction decay (FID), Fourier transform (FT)
Learning Objective: 15.3 State the significance of the number of signals, along with their
locations, areas, and shapes, in am NMR spectrum
Difficulty: Easy
17. Which of the following type(s) of protons are chemically non-equivalent?
A. homotopic
B. enantiotopic
C. diastereotopic
D. A & B
E. B & C
Answer: C
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
18. Which of the following type(s) of protons are chemically equivalent?
A. homotopic
B. enantiotopic
C. diastereotopic
D. A & B
E. B & C
Answer: D
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Easy
19. Protons Ha and Hb in the following compound are _________.
A. homotopic
B. enantiotopic
C. diastereotopic
D. mesotopic
E. none of these
Answer: A
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Easy
20. Protons Ha and Hb in the following compound are _________.
A. homotopic
B. enantiotopic
C. diastereotopic
D. mesotopic
E. none of these
Answer: B
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
21. Protons Ha and Hb in the following compound are _________.
A. homotopic
B. enantiotopic
C. diastereotopic
D. mesotopic
E. none of these
Answer: C
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
22. Protons Ha and Hb in the following compound are _________.
A. homotopic
B. enantiotopic
C. diastereotopic
D. mesotopic
E. none of these
Answer: C
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
23. Protons Ha and Hb in the following compound are _________.
A. homotopic
B. enantiotopic
C. diastereotopic
D. mesotopic
E. none of these
Answer: C
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
24. Protons Ha and Hb in the following compound are _________.
A. homotopic
B. enantiotopic
C. diastereotopic
D. mesotopic
E. none of these
Answer: C
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
25. Protons Ha and Hb in the following compound are _________.
A. homotopic
B. enantiotopic
C. diastereotopic
D. mesotopic
E. none of these
Answer: C
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
26. Protons Ha and Hb in the following compound are _________.
A. homotopic
B. enantiotopic
C. diastereotopic
D. mesotopic
E. none of these
Answer: A
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
27. How many signals would you expect in the 1H NMR spectrum of CH3OCH2CH3?
A. 1
B. 2
C. 3
D. 4
E. 5
Answer: C
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
28. How many signals would you expect in the 1H NMR spectrum of
CH3OCH2CH2OCH3?
A. 1
B. 2
C. 3
D. 4
E. 5
Answer: B
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
29. How many signals would you expect in the 1H NMR spectrum of
(CH3)2CHCH2CH2CH3?
A. 1
B. 2
C. 3
D. 4
E. 5
Answer: E
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
30. How many signals would you expect in the 1H NMR spectrum of
HOCH2CH2CH2CH2OH?
A. 1
B. 2
C. 3
D. 4
E. 5
Answer: C
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
31. How many signals would you expect in the 1H NMR spectrum of the following
compound?
A. 4
B. 5
C. 6
D. 7
E. 8
Answer: D
Learning Objective: 15.4 Describe chemical equivalence and a procedure for
determining whether two protons are homotopic, enantiotopic, or not chemically
equivalent
Difficulty: Medium
32. How many signals would you expect in the 1H NMR spectrum of the following
compound?
