Chapter 15 Flashcards

1
Q
  1. Which feature in the 1H NMR spectrum provides information about the number of types of different protons in a compound?
    A. number of signals
    B. integral
    C. splitting
    D. chemical shift
A

A. number of signals

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2
Q
  1. Which feature in the 1H NMR spectrum provides information about the relative number of each type of proton in a compound?
    A. number of signals
    B. integral
    C. splitting
    D. chemical shift
A

B. integral

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3
Q
  1. Which feature in the 1H NMR spectrum provides information about the electronic environment of the protons in a compound?
    A. number of signals
    B. integral
    C. splitting
    D. chemical shift
A

D. chemical shift

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4
Q
  1. Which feature in the 1H NMR spectrum provides information about the number of neighboring protons of each proton in the compound?
    A. number of signals
    B. integral
    C. multiplicity
    D. chemical shift
A

C. multiplicity

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5
Q
  1. Which of the following is not true regarding 1H NMR spectroscopy?
    A. “shielding” leads to peaks at lower values of d
    B. a “downfield” peak appears at a higher value of d
    C. d for a particular proton depends on the magnetic field strength of the instrument used.
    D. on a 300 MHz instrument, a proton that adsorbs irradiation at a frequency 1200 Hz higher than the adsorption of TMS appears at d 4 ppm.
A

C. d for a particular proton depends on the magnetic field strength of the instrument used.

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6
Q
  1. Which of the following is not true regarding 1H NMR spectroscopy?
    A. a “downfield” peak appears at a lower value of d
    B. on a 300 MHz instrument, a proton that adsorbs irradiation at a frequency 900 Hz higher than the adsorption of TMS appears at d 3 ppm.
    C. d for a particular proton is independent of the magnetic field strength of the instrument used.
    D. “deshielding” leads to peaks at higher values of d
A

A. a “downfield” peak appears at a lower value of d

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7
Q
  1. How many sets of equivalent protons are there in hexane?
    A. 2
    B. 3
    C. 6
    D. 7
A

B. 3

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8
Q
  1. How many sets of equivalent protons are there in 2-methylhexane?
    A. 2
    B. 3
    C. 6
    D. 7
A

C. 6

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9
Q
  1. How many sets of equivalent protons are there in 3-methylhexane?
    A. 2
    B. 3
    C. 6
    D. 7
A

D. 7

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10
Q
  1. What is the splitting of the signal in the 1H NMR spectrum for the methyl protons of ethane?
    A. singlet
    B. doublet
    C. triplet
    D. quartet
A

A. singlet

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11
Q
  1. What is the splitting of the signal in the 1H NMR spectrum for the methyl protons of propane?
    A. singlet
    B. doublet
    C. triplet
    D. quartet
A

C. triplet

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12
Q
  1. What is the splitting of the signal in the 1H NMR spectrum for the methyl protons of 1-bomo-2-methylpropane?
    A. singlet
    B. doublet
    C. triplet
    D. nonet
A

B. doublet

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13
Q
  1. Which of the following combinations of peaks appears in the 1H NMR spectrum of diethyl ether, CH3CH2OCH2CH3?
    A. a triplet and a doublet
    B. a quartet and a sextet
    C. two singlets
    D. a triplet and a quartet
A

D. a triplet and a quartet

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14
Q
  1. Which of the following combinations of peaks appears in the 1H NMR spectrum of butane?
    A. a triplet and a doublet
    B. a triplet and a quartet
    C. a triplet and a sextet
    D. two singlets
A

B. a triplet and a quartet

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15
Q
  1. Which of the following combinations of peaks appears in the 1H NMR spectrum of 2,3-dimethylbutane?
    A. two doublets
    B. a doublet and a septet
    C. a singlet and two doublets
    D. a doublet and an octet
A

A. two doublets

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16
Q
  1. Which of the following combinations of peaks appears in the 1H NMR spectrum of 1,2-dimethyoxyethane, CH3OCH2CH2OCH3?
    A. two singlets
    B. a singlet and a triplet
    C. a singlet and two triplets
    D. a doublet and a triplet
A

B. a singlet and a triplet

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17
Q
  1. Which of the following combinations of peaks appears in the 1H NMR spectrum of 1,4-dimethyoxyethane, CH3OCH2CH2CH2CH2OCH3?
    A. three singlets
    B. a singlet, a triplet, and a quintet
    C. a singlet and two triplets
    D. a doublet and a triplet
A

C. a singlet and two triplets

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18
Q
  1. Which of the following combinations of peaks appears in the 1H NMR spectrum of 2-methylpropane?
    A. two singlets
    B. a singlet and a nonet
    C. a singlet and a decet
    D. a doublet and a decet
A

D. a doublet and a decet

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19
Q
  1. What is the appearance of the signal corresponding to the CH2 protons in the 1H NMR spectrum of ethyl methyl ether, CH3CH2OCH3?
    A. a doublet
    B. a triplet
    C. a quartet
    D. a septet
A

C. a quartet

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20
Q
  1. Which C4H9Br compound gives a triplet at approximately 3.5 ppm in the 1H NMR spectrum?
A

A. 1

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21
Q
  1. Which C4H9Br compound gives a doublet at approximately 3.3 ppm in the 1H NMR spectrum?
A

C. 3

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22
Q
  1. What is the relative area of the six peaks in a sexet in an 1H NMR spectrum?
    A. 1:2:3:3:2:1
    B. 1:3:6:6:3:1
    C. 1:5:10:10:5:1
    D. 1:6:15:15:6:1
A

C. 1:5:10:10:5:1

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23
Q
  1. What is the relative area of the six peaks in a septet in an 1H NMR spectrum?
    A. 1:2:3:4:3:2:1
    B. 1:3:6:12:6:3:1
    C. 1:6:15:30:15:6:1
    D. 1:6:15:20:15:6:1
A

D. 1:6:15:20:15:6:1

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24
Q
  1. How many signals appear in proton-decoupled 13C NMR spectrum of 3,4-dimethylhexane?
    A. 3
    B. 4
    C. 5
    D. 6
A

B. 4

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25
Q
  1. How many signals appear in proton-decoupled 13C NMR spectrum of 2,5-dimethylhexane?
    A. 3
    B. 4
    C. 5
    D. 6
A

A. 3

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26
Q
  1. Which of the protons in the following molecule appear furthest downfield in the 1H NMR spectrum?
A

D. iv

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27
Q
  1. Which of the protons in the following molecule appear furthest downfield in the 1H NMR spectrum?
A

C. iii

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28
Q
  1. Which of the protons in the following molecule appear furthest downfield in the 1H NMR spectrum?
A

D. iv

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29
Q
  1. Which of the protons in the following molecule appear at the highest d-value in the 1H NMR spectrum?
A

D. iv

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30
Q
  1. Which of the protons in the following molecule appear at the highest d-value in the 1H NMR spectrum?
A

A. i

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31
Q
  1. Which of the protons in the following molecule appear at the highest d-value in the 1H NMR spectrum?
A

C. iii

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32
Q
  1. How many signals appear in the proton-decoupled 13C NMR spectrum of 1,4-dibromobenzene?
    A. 1
    B. 2
    C. 3
    D. 4
A

B. 2

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33
Q
  1. How many signals appear in the proton-decoupled 13C NMR spectrum of 1,3-dibromobenzene?
    A. 1
    B. 2
    C. 3
    D. 4
A

D. 4

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34
Q
  1. How many signals appear in the proton-decoupled 13C NMR spectrum of 1,2-dibromobenzene?
    A. 1
    B. 2
    C. 3
    D. 4
A

C. 3

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35
Q
  1. How many signals appear in the proton-decoupled 13C NMR spectrum of 4-bromotoluene?
    A. 3
    B. 4
    C. 5
    D. 7
A

C. 5

36
Q
  1. How many signals appear in the proton-decoupled 13C NMR spectrum of 3-bromotoluene?
    A. 3
    B. 4
    C. 5
    D. 7
A

D. 7

37
Q
  1. How many signals appear in the proton-decoupled 13C NMR spectrum of 2-bromotoluene?
    A. 3
    B. 4
    C. 5
    D. 7
A

D. 7

38
Q
  1. Which C4H9Br compound(s) gives a 13C NMR spectrum consisting of four signals?
A

B. only 1 and 2

39
Q
  1. Which C4H9Br compound(s) gives a 13C NMR spectrum consisting of two signals?
A

B. only 2

40
Q
  1. Which of the following compounds gives a 1H NMR spectrum consisting of two singlets and a 13C NMR consisting of consisting of three signals?
A

C. only ii and iii

41
Q
  1. Which of the following compounds would give a 1H NMR spectrum consisting of two singlets and a 13C NMR consisting of consisting of three signals?
A

D. iii and iv

42
Q
  1. How many signals appear in the proton-decoupled 13C NMR spectrum of the following compound?
A

C. 9

43
Q
  1. How many signals appear in the proton-decoupled 13C NMR spectrum of the following compound?
A

B. 7

44
Q
  1. Which of the carbon atoms in the following molecule appears furthest downfield in the 13C NMR spectrum?
A

C. iii

45
Q
  1. Which of the carbon atoms in the molecule appears furthest downfield in the 13C NMR spectrum?
A

D. iv

46
Q
  1. The chemical shift of the protons of acetone, CH3COCH3, is 2.1 ppm when the spectrum is obtained at 250 MHz. What is the chemical shift of these protons when the spectrum is acquired at 500 MHz?
    A. 1.05 ppm
    B. 2.1 ppm
    C. 4.2 ppm
    D. 8.4 ppm
A

B. 2.1 ppm

47
Q
  1. The coupling constant, J, between the protons of chloroethane is 7 Hz when the spectrum is obtained at 250 MHz. What is the coupling constant between these protons when the spectrum is acquired at 500 MHz?
    A. 3.5 Hz
    B. 7 Hz
    C. 14 Hz
    D. 21 Hz
A

B. 7 Hz

48
Q
  1. What is the hydrogen deficiency index for a compound with a molecular formula of C10H16O2?
    A. 1
    B. 2
    C. 3
    D. 4
A

C. 3

49
Q
  1. What is the hydrogen deficiency index for a compound with a molecular formula of C12H16O?
    A. 2
    B. 4
    C. 5
    D. 6
A

C. 5

50
Q
  1. What is the hydrogen deficiency index for a compound with a molecular formula of C6H11N?
    A. 1
    B. 2
    C. 3
    D. 4
A

B. 2

51
Q
  1. What is the hydrogen deficiency index for a compound with a molecular formula of C6H6Br2?
    A. 1
    B. 2
    C. 3
    D. 4
A

C. 3

52
Q
  1. Which of the following compounds gives a 1H NMR spectrum consisting of only a singlet?
    A. 1,1-dibromopropane
    B. 1,2-dibromopropane
    C. 1,3-dibromopropane
    D. 2,2-dibromopropane
A

D. 2,2-dibromopropane

53
Q
  1. Which of the following compounds gives a 1H NMR spectrum consisting of only two singlets?
    A. CH3OCH2CH2OCH2CH3
    B. CH3OCH2CH2CH2CH2OH
    C. CH3OC(CH3)2OCH3
    D. CH3OCH2CH(CH3)OCH3
A

C. CH3OC(CH3)2OCH3

54
Q
  1. Which of the following compounds gives a 1H NMR spectrum consisting of only two triplets and a singlet?
    A. CH3CH(OCH3)2
    B. CH3OCH2CH2CH2CH2OCH3
    C. CH3OCH2CH2OCH3
    D. CH3OCH2CH(OH)CH3
A

B. CH3OCH2CH2CH2CH2OCH3

55
Q
  1. Which of the following compounds gives a 1H NMR spectrum consisting of only a singlet, triplet and quintet?
    A. CH3OCH2CH2CH2CH2OH
    B. CH3OCH2CH2OCH2CH3
    C. CH3OCH2CH2CH2OCH3
    D. CH3OCH2CH(CH3)OCH3
A

C. CH3OCH2CH2CH2OCH3

56
Q
  1. Which of the protons in the following molecule appear at the highest d-value in the 1H NMR spectrum?
A

D. iv

57
Q
  1. Which of the following compounds have homotopic protons?
  2. propane
  3. butane
  4. 2-methylpropane

A. only 1
B. only 2
C. only 1 and 2
D. 1, 2 and 3

A

D. 1, 2 and 3

58
Q
  1. Which of the following compounds have enantiotopic protons?
  2. propane
  3. butane
  4. 2-methylpropane

A. only 1
B. only 2
C. only 1 and 2
D. 1, 2 and 3

A

B. only 2

59
Q
  1. Which of the following is true for pair of homotropic protons?
  2. They will appear at the same chemical shift in an achiral (i.e., nonchiral) environment
  3. They will appear at the same chemical shifts in a chiral environment

A. only 1
B. only 2
C. neither 1 nor 2
D. both 1 and 2

A

D. both 1 and 2

60
Q
  1. Which of the following is true for pair of enantiotopic protons?
  2. They will appear at the same chemical shift in an achiral (i.e., nonchiral environment)
  3. They will appear at the same chemical shifts in a chiral environment

A. only 1
B. only 2
C. neither 1 nor 2
D. both 1 and 2

A

A. only 1

61
Q
  1. Which of the following is true for pair of diastereotopic protons?
  2. They will appear at the same chemical shift in an achiral (i.e., nonchiral environment)
  3. They will appear at the same chemical shifts in a chiral environment

A. only 1
B. only 2
C. neither 1 nor 2
D. both 1 and 2

A

C. neither 1 nor 2

62
Q
  1. Which C9H10O compound gives the following 1H NMR spectrum?
A

B. 2

63
Q
  1. Which C9H10O compound gives the following 1H NMR spectrum?
A

A. 1

64
Q
  1. Which C6H12O2 compound gives the following 1H NMR spectrum?
A

B. 2

65
Q
  1. Which C6H12O2 compound gives the following 1H NMR spectrum?
A

C. 3

66
Q
  1. Which C8H10 compound gives the following 1H NMR spectrum?
A

A. 1

67
Q
  1. Which C8H10 compound gives the following 1H NMR spectrum?
A

C. 3

68
Q

1H nuclei located near electronegative atoms tend to be ________ relative to 1H nuclei which are not.

A) shielded

B) deshielded

C) resonanced

D) split

E) none of the above

A

B) deshielded

69
Q

8) How many signals would you expect to see in the 1H NMR spectrum of the following compound?

A

D) 4

70
Q

9) How many signals would you expect to see in the 1H NMR spectrum of the following compound?

A

E) 2

71
Q

10) How many signals would you expect to see in the 1H NMR spectrum of the following compound?

A

C) 3

72
Q

11) How many signals would you expect to see in the 1H NMR spectrum of the following compound?

A

D) 3

73
Q

12) How many signals would you expect to see in the 1H NMR spectrum of the following compound?

A

A) 2

74
Q

13) How many signals would you expect to see in the 1H NMR spectrum of the following compound?

A

E) 3

75
Q

17) How many proton NMR singlets will 2-bromo-3-methyl-2-butene exhibit?

A) 1

B) 2

C) 3

D) 4

E) 5

A

C) 3

76
Q

19) Determine the number of signals for 4-methyl-1-propylbenzene in the 1H NMR spectrum.

A) 4

B) 5

C) 6

D) 7

E) 8

A

C) 6

77
Q

22) Using a 60 MHz spectrometer, the protons in dichloromethane appear at 5.30 ppm. When the same sample is placed in a 100 MHz instrument, where does the signal appear?

A) 8.33 ppm

B) 3.18 ppm

C) 5.30 ppm

D) cannot be determined from information given

A

C) 5.30 ppm

78
Q

24) Which of the following protons gives an NMR signal with the highest chemical shift value (farthest downfield)?

A

A) 1

79
Q

25) Which of the following protons gives an NMR signal with the lowest chemical shift value (farthest upfield)?

A

C) 3

80
Q

26) Which of the following protons gives an NMR signal with the highest chemical shift value (farthest downfield)?

A

B) 2

81
Q

27) Which of the following methyl groups will exhibit the most downfield (highest) chemical shift in 1H NMR spectroscopy?

A

B) II

82
Q

29) Which of the following protons gives an NMR signal with the lowest chemical shift value (farthest upfield)?

A

A) 1

83
Q

31) What is the ratio of the protons in the following compound?

A

C) 9:2

84
Q

38) How many distinct triplets would you expect in the 1H NMR of the compound below?

A

B) 2

85
Q

42) Which of the following technique(s) can readily distinguish between:

A

E) A and C

86
Q

44) Which compound has a 1H NMR spectrum consisting of the following peaks:
0. 9 (6H, d), 1.0 (3H, t), 2.2 (2H, q), and 4.0 (1H, septet)?

A) (CH3)2CHCH2O2CCH3

B) (CH3)2CHCH2CO2CH3

C) (CH3)2CHO2CCH2CH3

D) (CH3)2CHCO2CH2CH3

E) (CH3)2CHOCH2CH3

A

C) (CH3)2CHO2CCH2CH3

87
Q
A