ch9 Test-Bank
ch9 Test-Bank
ch9 Test-Bank
1) How many signals would you expect to find in the 1H NMR spectrum of
CH3OCH2CH2OCH3?
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: B
2) Predict the splitting pattern you would observe for the proton at C1 of 2,3-dimethyl-2-
phenylbutane.
A) Doublet
B) Singlet
C) Quartet
D) Septet
E) Octet
Answer: B
3) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
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CH3
O
Answer: C
4) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
O
Answer: B
5) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
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Answer: C
6) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
O
Answer: E
7) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow in the compound nicotine?
Answer: C
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8) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow in the compound nicotine?
Answer: C
9) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow in the compound nicotine?
Answer: E
10) Which one of the following best represents the predicted approximate chemical shift and
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Answer: A
11) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
H
Answer: D
12) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
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Answer: B
13) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
Answer: E
14) For the following compound how many different signals would you see in the proton NMR?
(Assume that you can see them all.)
A) 4
B) 5
C) 6
D) 7
E) 8
Answer: A
15) For the compound dimedone, how many different signals would you see in the proton NMR?
(Assume that you can see them all.)
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A) 2
B) 3
C) 4
D) 5
E) None of these choices.
Answer: B
16) For the following compound how many different signals would you see in the proton NMR?
(Assume that you can see them all.)
H3CO
A) 4
B) 5
C) 6
D) 7
E) 8
Answer: C
17) For the following compound how many different signals would you see in the proton NMR?
(Assume that you can see them all.)
A) 1
B) 2
C) 3
D) 4
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E) 5
Answer: C
18) For the compound adamantine, how many different signals would you see in the proton
NMR? (Assume that you can see them all.)
A) 1
B) 2
C) 3
D) 4
E) None of these choices.
Answer: B
A) CH3CCH2CH3
H
B) C6H5CH2C O
H
C) (CH3)2CHC O
H
D) (CH3)3CC O
O
E) C6H5CH2CCH3
Answer: D
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20) For the following compound how many different signals would you see in the proton NMR?
(Assume that you can see them all.)
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: D
22) For the following compound how many different signals would you see in the proton NMR?
(Assume that you can see them all.)
A) 4
B) 5
C) 6
D) 7
E) 8
Answer: B
23) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
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CH3
O
Answer: D
24) Predict the splitting pattern you would observe for the proton at C4 of 2,3-dimethyl-2-
phenylbutane.
A) Doublet
B) Singlet
C) Quartet
D) Septet
E) Octet
Answer: A
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: C
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26) How many chemically distinct 1H NMR signals are there in the following compound?
ClCH2CHCH3
Br
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: D
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: CB
28) How many 1H NMR signals would you expect from this compound?
OCH3
OCH3
A) 1
B) 2
C) 3
D) 4
E) 5
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Answer: B
29) The 1H NMR spectrum of which of these compounds would consist of a triplet, singlet and
quartet only?
A) 2-chloro-4-methylpentane
B) 3-chloro-2-methylpentane
C) 3-chloropentane
D) 1-chloro-2,2-dimethylbutane
E) 3-chloro-3-methylpentane
Answer: E
30) Which one of the following best represents the predicted approximate chemical shift and
coupling for the hydrogen(s) indicated with the arrow?
H
Answer: D
31) Which of the following compounds would not be represented by a lone singlet in the proton
NMR?
A) cyclohexane
B) benzene
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Answer: D
32) A compound C5H11Cl which exhibits only two singlets in the 1H NMR spectrum must be:
A) 1-Chloropentane
B) 1-Chloro-2,2-dimethylpropane
C) 1-Chloro-2-methylbutane
D) 3-Chloropentane
E) 1-Chloro-3-methylbutane
Answer: B
33) A compound that would show two triplets and a septet in the 1H NMR spectrum could be:
A) 3-ethylpentane
B) 2-bromopropane
C) chlorocyclopropane
D) 1-iodopropane
E) none of these choices
Answer: C
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Answer: C
Answer: E
36) The 1H NMR signal for which of the indicated protons will occur at the lowest frequency
(most upfield signal)?
A) I
B) II
C) III
D) IV
E) V
Answer: A
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37) If all the protons of 1-fluoropentane could be discerned, which would you expect to be at the
lowest field in the 1H NMR spectrum of this compound?
CH3CH2CH2CH2CH2F
V IV III II I
A) Protons on carbon I
B) Protons on carbon II
C) Protons on carbon III
D) Protons on carbon IV
E) Protons on carbon V
Answer: A
38. The 1H NMR signal for which of the indicated protons occurs farthest downfield?
III
Cl H
H C C C C CH3
I H IV
II
V
A) I
B) II
C) III
D) IV
E) V
Answer: E
39) Which proton(s) of the compound below would appear as a septet in the 1H NMR spectrum?
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I CH3
CH3CH2CH2-O-CH
CH3
V IV III II
I
A) The protons on carbon I
B) The protons on carbon II
C) The protons on carbon III
D) The protons on carbon IV
E) The protons on carbon V
Answer: B
40) Which proton(s) of the compound below would appear as a doublet in the 1H NMR
spectrum?
I CH3
CH3CH2CH2-O-CH
CH3
V IV III II
I
A) The protons on carbon I.
B) The protons on carbon II.
C) The protons on carbon III.
D) The protons on carbon IV.
E) The protons on carbon V.
Answer: A
41) Which proton(s) of the compound below would appear as a triplet in the 1H NMR spectrum?
I CH3
CH3CH2CH2-O-CH
CH3
V IV III II
I
A) The protons on carbon II.
B) The protons on carbon I and V.
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Answer: C
42) Predict the splitting pattern you would observe for the proton at C3 of 2,3-dimethyl-2-
phenylbutane.
A) Doublet
B) Singlet
C) Quartet
D) Septet
E) Octet
Answer: D
43) Which of these compounds will not be represented by a singlet only in the 1H NMR
spectrum?
A) Neopentane
B) Hexamethylbenzene
C) Isobutane
D) (Z)-1,2-Dichloroethene
E) (E)-1,2-Dichloroethene
Answer: C
44) Consider the expected splitting of the C2 proton signal in the 1H NMR spectrum of 1,1-
dibromopentane. Presuming that the coupling constants for neighboring protons are sufficiently
different, and that the instrument has sufficient resolving power, what is the theoretical
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A) 3
B) 4
C) 5
D) 6
E) 8
Answer: D
45) Consider the expected splitting of the C2 proton signal in the 1H NMR spectrum of 2-ethyl-
1,3-propanediol. Presuming that the coupling constants for neighboring protons are sufficiently
different, and that the instrument has sufficient resolving power, what is the theoretical
multiplicity of the C2 proton signal?
A) 6
B) 7
C) 8
D) 12
E) 15
Answer: E
46) What is the theoretical multiplicity of the C-2 proton signal in the 1H NMR spectrum of 2-
hydroxymethyl-1,3-propanediol, shown below?
OH
HO OH
A) 1
B) 6
C) 7
D) 8
E) 9
Answer: C
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Section: 9.2
Difficulty Level: Hard
47) Consider the 1H NMR spectrum of very pure 1-propanol. Assuming the maximum
multiplicity of signals and non-superposition of peaks, what is the expected signal splitting
pattern for each signal, in the order (a, b, c, d) ?
CH3-CH2-CH2-OH
a b c d
A) 3, 6, 4, 1
B) 3, 6, 4, 3
C) 3, 12, 3, 1
D) 3, 12, 3, 3
E) 3, 12, 6, 3
Answer: E
48) The 1H NMR spectrum of which of the compounds below, all of formula C7H12O2, would
O O
O O
O O
I II III
O O O
A) I
B) II
C) III
D) IV
E) V
Answer: E
49) The 1H NMR spectrum of which of the compounds below, all of formula C7H12O2, would
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I II III
O O O
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: B
50) The 1H NMR spectrum of which of the compounds below, all of formula C7H12O2, would
consist of a singlet, a doublet and a triplet only?
O O
O O
O O
I II III
O O O
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: D
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51) A compound with the molecular formula C4H10O gives a 1H NMR spectrum consisting only
of a quartet centered at 3.5 and a triplet at 1.1. The most likely structure for the compound is:
CH3
CH3COH
A) CH3
CH3
B) CH3OCHOH
C) CH3CH2CH2CH2OH
D) CH3CH2OCH2CH3
CH3CHCH2OH
E) CH3
Answer: D
52) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C9H10O2? Relative integration is shown.
5
2
2
1
12 10 8 6 4 2 0
PPM
CHO
A)
CO2H
B)
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CO2H
C)
D) HO2C
CO2H
E)
Answer: C
53) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C8H14? Relative integration is shown.
3
2
8 7 6 5 4 3 2 1 0
PPM
A)
B)
C
C)
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D)
E)
Answer: D
54) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C6H11N? In the IR spectrum you notice a stretch at about 2250 cm-1. Relative
integration is shown.
A) CN
B)
CN
C)
CN
D)
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N
E) H
Answer: D
55) Determine the most likely structure of a compound, with the molecular formula C9H12, which
gave a 1H NMR spectrum consisting of:
a doublet at 1.25
a septet at 2.90 and
a multiplet at 7.25
I II III IV V ]
A) I
B) II
C) III
D) IV
E) V
Answer: D
56) A compound with the molecular formula C10H13Cl gave the following 1H NMR spectrum:
singlet, 1.6
singlet, 3.1
multiplet, 7.2 (5H)
The most likely structure for the compound is:
Cl Cl
Cl
I II III
Cl
Cl
IV V
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A) I
B) II
C) III
D) IV
E) V
Answer: B
57) A compound with the molecular formula C8H9BrO gave the following 1H NMR spectrum:
triplet, 1.4
quartet, 3.9
multiplet, 7.0 (4H)
There was no evidence of an -OH band in the IR spectrum. A possible structure for the
compound is:
O O Br O
Br
Br
I II III
O
Br
Br
O
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: C
58) A compound with the molecular formula C6H15N gave the following 1H NMR spectrum:
triplet, 0.90
quartet, 2.4
There were no other signals. The most likely structure for the compound is:
CH3NCH2CH3
A) CH2CH2CH3
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CH3NCH2CH2CH2CH3
B) CH3
C) CH3CH2CH2CH2CH2CH2NH2
CH3CH2NCH2CH3
D) CH2CH3
CH3CH2CH2NCH2CH2CH3
E) H
Answer: D
59) A compound with the molecular formula C8H9ClO gave the following 1H NMR spectrum:
triplet, 3.7
triplet, 4.2
multiplet, 7.1
There was no evidence of an -OH band in the IR spectrum. The most likely structure for the
compound is:
Cl
O O O
Cl
Cl
I II III
O
Cl
Cl
O
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: A
60) A compound with the molecular formula C3H6Cl2 gave a 1H NMR spectrum consisting only
of a triplet centered at 3.7 and a quintet centered at 2.2. The most likely structure for the
compound is:
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A) CH3CH2CHCl2
B) CH3CHClCH2Cl
C) ClCH2CHClCH3
D) ClCH2CH2CH2Cl
E) CH3CCl2CH3
Answer: D
61) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C10H20? Relative integration is shown.
3
2
8 7 6 5 4 3 2 1 0
PPM
A)
B)
C)
D)
E)
Answer: C
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62) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C4H8O? Relative integration is shown.
1 1
8 7 6 5 4 3 2 1 0
PPM
A) O
B) OH
OH
C)
O
D)
O
E)
Answer: D
63) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C10H12O2? Relative integration is shown.
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3
2 2 2 2
1
11 10 9 8 7 6 5 4 3 2 1 0
PPM
CHO
A) O
O
O
B)
CO2H
C)
CO2H
D)
CO2H
E)
Answer: C
64) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C8H16O? Relative integration is shown.
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2 2 2
2 1 0
PPM
A)
O
H
B)
OH
C)
D) O
O
E)
Answer: E
65) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C6H10O2? Relative integration is shown.
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2 2 2
6 5 4 3 2 1 0
PPM
A) O
O
O
B) H
C) O
O
D) O
O
E) OH
Answer: D
66) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C9H12O? Relative integration is shown.
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2 2 2 2
1
exchanges with D2O
7 6 5 4 3 2 1 0
PPM
A)
HO
B)
HO
C)
OH
D)
E) HO
Answer: E
67) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C5H8O? The IR spectrum does show a characteristic stretch around 1700 cm-
1
. Relative integration is shown.
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3 3
1 1
8 7 6 5 4 3 2 1 0
PPM
O
A)
O
B)
O
C)
O
D)
O
E)
Answer: E
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O
O O
I II III
O
O
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: E
A) CH3CH2CHBrCH3
B) CH3CH2CH2CH2Br
C) (CH3)2CHCH2Br
D) (CH3)3CBr
Answer: A
70) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C6H12O which shows no characteristic stretches in the IR between 3600-3300
cm-1, but does around 1600 cm-1? Relative integration is shown.
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1 1 1
6 5 4 3 2 1 0
PPM
A)
O
B)
C) O
O
D)
O
E)
Answer: A
71) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C6H12O2? Relative integration is shown.
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3 3
2 2 2
10 8 6 4 2 0
PPM
A) O
O
B) HO
O
C)
O
D) O
O
E) O
Answer: D
72) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C6H12? Relative integration is shown.
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3
2
1
8 7 6 5 4 3 2 1 0
PPM
A)
B)
C)
D)
E)
Answer: B
73) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C4H7Br? Relative integration is shown.
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3
2
1 1
6 5 4 3 2 1 0
PPM
A) Br
Br
B)
C) Br
Br
D)
Br
E)
Answer: C
74) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C5H10O? The IR spectrum does not show any characteristic stretches around
1700 cm-1. Relative integration is shown.
3 3
2
1 1
7 6 5 4 3 2 1 0
PPM
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O
A)
O
B)
O
C)
O
D)
E) O
Answer: A
75) A compound with the molecular formula C10H14 gave the following 1H NMR spectrum:
doublet, 1.2
singlet, 2.3
septet, 2.8
multiplet, 7.1
I II III
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: B
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76) Determine the likely structure for a compound A (C6H10O), which is found to decolorize
bromine in carbon tetrachloride. Its spectral data is as follows:
1
H NMR IR
triplet, 1.0 singlet, 2.4 -1
2200 cm (sharp)
singlet, 1.4 singlet, 3.4 3300 cm-1 (sharp)
quartet, 1.6 3500 cm-1 (broad)
OH
OH OH
I II III
OH
OH
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: C
Hb Ha
A) Identical
B) Enantiotopic
C) Diastereotopic
D) Homotopic
E) Mesotopic
Answer: C
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A) homotopic protons.
B) vicinal protons.
C) enantiotopic protons.
D) diastereotopic protons.
E) isomeric protons.
Answer: C
A) homotopic protons.
B) vicinal protons.
C) enantiotopic protons.
D) diastereotopic protons.
E) isomeric protons.
Answer: D
Ha H
b
A) homotopic protons.
B) vicinal protons.
C) enantiotopic protons.
D) diastereotopic protons.
E) isomeric protons.
Answer: D
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A) homotopic protons.
B) geminal protons.
C) enantiotopic protons.
D) diastereotopic protons.
E) isomeric protons.
Answer: D
82) Consider the expected splitting of signal “b” in the 1H NMR spectrum of 1-methoxy-2-
methylpropane, shown below. Presuming that Jab is sufficiently different from Jbc and that the
instrument has sufficient resolving power, what is the theoretical multiplicity of signal “b”?
a
O
b
a c d
A) 8
B) 9
C) 12
D) 21
E) 24
Answer: D
83) For the C2 methylene group in 1-bromopropane, the theoretical multiplicity in the 1H NMR
spectrum, presuming that Jab is sufficiently different from Jbc and that the instrument has
sufficient resolving power, is which of these?
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c b a
A) 2
B) 5
C) 6
D) 8
E) 12
Answer: E
84) Consider the expected splitting of signal “b” in the 1H NMR spectrum of N-methyl-1-
propanamine, shown below. Presuming that Jab is sufficiently different from Jbc and that the
instrument has sufficient resolving power, what is the theoretical multiplicity of signal “b”?
d
b H
N
a c e
A) 2
B) 5
C) 6
D) 8
E) 12
Answer: E
85) Consider the expected splitting of signal “b” in the 1H NMR spectrum of 1,1-dichloro-3-
methylbutane, shown below. Presuming that Jab is sufficiently different from Jbc and that the
instrument has sufficient resolving power, what is the theoretical multiplicity of signal “b”?
a Cl
b d Cl
a c
A) 8
B) 9
C) 12
D) 18
E) 21
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Answer: E
86) Consider the expected splitting of signal “b” in the 1H NMR spectrum of 1,2-
dimethoxypropane, shown below. Presuming that Jbc is sufficiently different from Jbd and that
the instrument has sufficient resolving power, what is the theoretical multiplicity of signal “b”?
c
O
a O b
d e
A) 2
B) 5
C) 6
D) 8
E) 12
Answer: E
87) Consider the expected splitting of signal “c” in the 1H NMR spectrum of 2-ethyl-1-butanol,
shown below. Presuming that Jbc is sufficiently different from Jcd and that the instrument has
sufficient resolving power, what is the theoretical multiplicity of signal “c”?
b a
OH
a c e
b d
A) 6
B) 7
C) 8
D) 12
E) 15
Answer: E
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88) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C9H14O? IR data shows no characteristic peak around 1700 cm-1. The 13C-
NMR chemical shifts (ppm): 108.4, 50.9, 31.6, 23.5, 2.0. Relative integration is known.
6
3 3
3 2 1 0
PPM
O
O
A)
O
B) O
O
C)
O
D) O
E) O O
Answer: C
89) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C5H11NO, which shows a characteristic stretch in the IR around 1700 cm-1,
and a characteristic peak at 202 ppm in the 13C-NMR? Relative integration is shown.
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2 2
10 9 8 7 6 5 4 3 2 1 0
PPM
CHO
A) H2N
N
B) CHO
C) O
CHO
N
D) H
N CHO
E)
Answer: B
90) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C8H15ClO3, which shows a characteristic stretch in the IR around 1750 cm-1
but not around 3500 cm-1, and a characteristic peak at 173 ppm in the 13C-NMR? Relative
integration is shown.
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2 2
4 3 2 1 0
PPM
O
O
Cl
O
A)
O
O
O
B) Cl
O
O
Cl
O
C)
O
O
Cl
O
D)
O
O
O
E) Cl
Answer: C
91) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C5H11NO? In the 13C-NMR spectrum you notice that the farthest peak
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3 3
2 2
1
exchanges with D2O
9 8 7 6 5 4 3 2 1 0
PPM
N
A) H
O
N
B) H
O
N
C) H
HN
O
D)
O
H N
E)
Answer: A
92) The broadband proton-decoupled 13C NMR spectrum of a hexyl chloride exhibits five
signals. Which of these structures could be the correct one for the compound?
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CH3
CH3CCH2CH2Cl
A) CH3
Cl
CH3CH2CCH2CH3
B) CH3
CH3 CH3
CH3C CHCH3
C) Cl
CH3
CH3CHCHCH2CH3
D) Cl
CH3
CH3C CHCH3
E) CH3 Cl
Answer: D
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: C
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Cl
Cl
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: D
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: D
96) For the compound dimedone, how many different signals would you see in the 13C NMR?
(Assume that you can see them all.)
A) 3
B) 4
C) 5
D) 6
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Answer: C
97) For the compound adamantine, how many different signals would you see in the 13C NMR?
(Assume that you can see them all.)
A) 1
B) 2
C) 3
D) 4
E) None of these choices.
Answer: B
98) How many 13C signals would you expect from anisole?
O
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: E
99) For the following compound how many different signals would you see in the carbon NMR?
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A) 3
B) 4
C) 5
D) 6
E) 7
Answer: C
100) In 13C NMR spectroscopy, the signal due to this type of carbon occurs furthest downfield.
A) –CN
C O
B)
C O
C)
C X
D)
E) –CC–
Answer: B
101) The C7 compound which gives 3 signals in the broadband proton-decoupled 13C spectrum
could be:
A) Heptane
B) 2-Methylhexane
C) 3,3-Dimethylpentane
D) 2,4-Dimethylpentane
E) 2,2,3-Trimethylbutane
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Answer: D
102) For the following compound how many different signals would you see in the carbon
NMR? (Assume that you can see them all.)
A) 1
B) 2
C) 3
D) 4
E) 5
Answer: E
103) For the following compound how many different signals would you see in the carbon
NMR? (Assume that you can see them all.)
A) 4
B) 5
C) 6
D) 7
E) 8
Answer: D
104) For the following compound how many different signals would you see in the carbon
NMR? (Assume that you can see them all.)
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A) 3
B) 4
C) 5
D) 8
E) 9
Answer: A
105) A bromodichlorobenzene which gives four signals in the broadband proton-decoupled 13C
spectrum could be:
Cl Br
Br Cl Br Cl
Cl Cl Cl
I II III
Cl
Br Cl Br
Cl Cl
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: A
106) For the following compound how many different signals would you see in the carbon
NMR? (Assume that you can see them all.)
S S
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A) 4
B) 5
C) 6
D) 7
E) 8
Answer: C
107) Which compound below would give rise to 3 signals in the proton NMR spectrum and 4
signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)
Br
I II III IV
A) I
B) II
C) III
D) IV
E) None of these choices.
Answer: E
108) Which compound below would give rise to 4 signals in the proton NMR spectrum and 4
signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)
Br
I II III IV
A) I
B) II
C) III
D) IV
E) More than one of the above.
Answer: C
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109) Which compound below would give rise to 4 signals in the proton NMR spectrum and 6
signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)
Br
I II III IV
A) I
B) II
C) III
D) IV
E) More than one of these choices.
Answer: A
110) Which compound below would NOT give rise to 4 signals in the proton NMR spectrum and
3 signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)
OH OH OH
OH
I II III IV
A) I
B) II
C) III
D) IV
E) All of these choices fit the criteria.
Answer: C
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111) Which compound below would give rise to 5 signals in the proton NMR spectrum and 7
signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)
Br
I II III IV
A) I
B) II
C) III
D) IV
E) None of these choices.
Answer: D
112) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C7H12O4? The 13C-NMR spectrum shows peaks at 14.1, 40.8, 61.0 and 166.8
ppm. Relative integration is shown.
3
2
1
5 4 3 2 1 0
PPM
O O
A) O O
H H
B) O O
O O
C) O O
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O
O
O
D) O
O
O
O
E) O
Answer: A
113) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C10H11N? Looking at the 13C-NMR you notice 10 distinct peaks, and the IR
has a characteristic peak around 2250 cm-1. Relative integration is shown.
4
3
2 2
8 7 6 5 4 3 2 1 0
PPM
A)
B) NC
CN
C)
D) CN
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H
N
E)
Answer: D
114) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C6H10O2? The 13C-NMR shows characteristic chemical shifts at 22.3, 31.1,
117.3, 157.7, and 171.6 ppm. Relative integration is shown.
1
exchanges w/ D2O 1 1 1
13 12 11 10 9 8 7 6 5 4 3 2 1 0
PPM
O
HO
A)
CO2H
B)
O
C) O
CO2H
D)
CO2H
E)
Answer: E
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115) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C11H14O2? Looking at the 13C-NMR you notice a peak at 174 ppm. Relative
integration is shown.
3
2 2 2 2
8 7 6 5 4 3 2 1 0
PPM
A) O
O
O
B)
O
C) O
D) O
E) O
Answer: A
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116) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C12H17NO and a characteristic IR stretch near 1700 cm-1 and a characteristic
peak in the 13C-NMR at 170 ppm? Relative integration is shown.
3 3 3
22 2 2
8 7 6 5 4 3 2 1 0
PPM
O
A)
B) O
C) HO
O
D)
O
E)
Answer: A
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117) What is the structure of the compound in the following 1H-NMR spectrum with the
molecular formula C9H18O2 and characteristic 13C-NMR peaks at 11.3, 21.6, 25.3, 49.4, 67.1,
and 175.5 ppm? Relative integration is shown.
3 3
2
1 1
6 5 4 3 2 1 0
PPM
O
A)
O
B)
C)
O
O
D)
O
O
E)
Answer: B
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A) 15
B) 29
C) 44
D) 45
E) 100
Answer: B
A) 15
B) 29
C) 44
D) 45
E) 100
Answer: C
120) A prominent (M-18) peak suggests that the compound might be a(n):
A) Alkane
B) Alcohol
C) Ether
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D) Ketone
E) Primary amine
Answer: B
A) m/z 15
B) m/z 92
C) m/z 43
D) m/z 57
E) m/z 77
Answer: D
122) An organic compound absorbs strongly in the IR at 1687 cm-1. Its 1H NMR spectrum
consists of two signals, a singlet at 2.1 ppm and a multiplet centered at 7.1 ppm. Its mass
spectrum shows significant peaks at m/z 120, m/z 105 and m/z 77. This information is consistent
with which of the following structures?
O
O
O
I II III
IV V
A) I
B) II
C) III
D) IV
E) V
Answer: A
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123) Select the structure of a compound C6H14 with a base peak at m/z 43.
A) CH3CH2CH2CH2CH2CH3
B) (CH3CH2)2CHCH3
C) (CH3)3CCH2CH3
D) (CH3)2CHCH(CH3)2
E) None of these choices.
Answer: D
m/z intensity
84 M 10.00
85 0.56
86 0.04
A) C5H10O
B) C5H8O
C) C5H24
D) C6H12
E) C4H6O2
Answer: B
m/z intensity
78 M 10.00
79 1
80 3.3
81 0.3
A) C6H6
B) C3H5Cl
C) C6H8
D) C6H9
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E) C3H7Cl
Answer: E
126) The mass spectra of alkyl bromides and chlorides are characterized by an unusually intense
___.
A) base peak
B) parent peak
C) Mpeak
D) M +2 peak
E) None of these choices.
Answer: D
127) The data below from the molecular ion region of the mass spectrum of a halogen-containing
compound are consistent with the presence of what halogen(s) in the original compound?
intensity
M51.0
M+2 100.0
M+4 49.0
A) One Br
B) One Cl
C) One Br and one Cl
D) Two Br
E) Two Cl
Answer: D
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Answer: True
129) Hydrogen that are diastereotopic will show different chemical signals in the proton NMR.
Answer: True
130) The predicted ratio of the relative peak sizes in a quintet signal would be about 1:3:5:3:1.
Answer: False
131) An acceptable solvent to use for a deuterium exchange experiment with an alcohol would
be CDCl3.
Answer: False
132) Compounds that contain a benzylic carbon will often show a peak with a m/z of 91 in a
mass spectrometry experiment.
Answer: True
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Topic: General
Section: 9.1
Difficulty Level: Easy
134) Briefly explain how you might distinguish between 1-butyne and 2-butyne by comparing
their 1H-NMR spectra.
Answer: 1-butyne will show 3 signals whereas 2-butyne will only show one signal
135) Briefly explain how you might distinguish between the following substances by comparing
their 1H-NMR spectra:
O
O
O
O
I II
Answer: The main difference would likely be in the chemical shift of the methine proton of the
isopropyl group. The methine proton in I is likely to be more deshielded, and produce a signal
(septet) at about 3.5 ppm, while the analogous proton in II is likely to be found, also as a septet,
at about 2.3 ppm.
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O
O
O
O
I ~3.5 ppm II ~2.3 ppm
136) Briefly explain how you might distinguish between the following substances by comparing
their 1H-NMR spectra:
Answer: The key distinguishing will be the carboxylic acid hydrogen which should occur very
far downfield from the other signal and appear as a broad singlet.
137) Briefly explain how you might distinguish between the following substances by comparing
their 1H-NMR spectra:
O
O
O
O
I II
Answer: The main difference would likely be in the chemical shifts of the methine proton of the
isopropyl group and the methylene proton closest to the ester function.
The methine proton in I is likely to be more deshielded, and produce a signal (septet) at about 3.5
ppm, while the analogous proton in II is likely to be found, also as a septet, at about 2.3 ppm.
By contrast, the methylene proton in II is likely to be more deshielded, and produce a signal
(triplet) at about 3.4 ppm, while the analogous proton in II is likely to be found, also as a triplet,
at about 2.2 ppm.
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I II
O
O
O
O
~3.5 ppm ~2.3 ppm
(septet) (septet)
~2.2 ppm ~3.4 ppm
(triplet) (triplet)
138) Briefly explain how you might distinguish between the following substances by comparing
their 1H-NMR spectra:
O H
N
N
H O
I II
Answer: The main difference would likely be in the chemical shifts of the methine proton of the
isopropyl group and the methylene proton closest to the amide function.
The methine proton in I is likely to be more deshielded, and produce a signal (septet) at about 3.5
ppm, while the analogous proton in II is likely to be found, also as a septet, at about 2.3 ppm.
By contrast, the methylene proton in II is likely to be more deshielded, and produce a signal
(triplet) at about 3.4 ppm, while the analogous proton in II is likely to be found, also as a triplet,
at about 2.2 ppm.
I II
O H
N
N
H O
~3.2 ppm ~2.3 ppm
(septet) (septet)
~2.2 ppm ~3.1 ppm
(triplet) (triplet)
139) Draw the structure for a compound that has the chemical formula C4H8O2 and shows one
singlet, one triplet and one quartet in the proton NMR.
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quartet
triplet
singlet
>
O O
>
>
>
Topic: 1H NMR
Section: 9.2
Difficulty Level: Medium
9-10 ppm
triplet
>
Cl
O
>
4-5 ppm
Answer: doublet
Topic: 1H NMR
Section 9.2
Difficulty Level: Medium
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Answer: Five
1 2 4
1' 3
OH
5
Topic: 1H NMR
Section: 9.2
Difficulty Level: Easy
143) When measuring the integral for a particular peak in the NMR spectrum, we are not
interested in the peak height as much as in the ___.
144) Examine the 1H NMR spectrum of 1-nitropropane, shown below. Assign the signals to the
respective hydrogen atoms in the molecule.
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4.3 ppm
triplet
>
>
1.0 ppm NO2
>
triplet
2.0 ppm
Answer: sextet
145) An unknown compound, A, has the formula C7H14O. Elucidate the structure of A by
scrutinizing its IR and1H NMR spectra, shown below.
Answer:
4-Heptanone
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Topic: General
Section: 9.4
Difficulty Level: Easy
147) What compound is used as the standard “zero” reference in both carbon and proton NMR?
Answer: Rotation about C-C single bonds; chemical exchange of protons attached to
electronegative atoms
Answer:
150) Interpret the following 13C/DEPT spectrum of a compound C5H10Br2: elucidate the structure
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32 ppm
>
>
Br Br
>
>
>
33 ppm 33 ppm
Answer: 27 ppm
151) An unknown compound, C, has the formula C7H7Br. Elucidate the structure of C by
scrutinizing its IR, 1H NMR and 13C NMR spectra, shown below.
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Answer: Br
4-Bromotoluene
152) An unknown compound, F, has the formula C3H6O2. Elucidate the structure of F by
scrutinizing its IR, 1H NMR and 13C NMR spectra, shown below.
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Answer: OH
Propanoic acid
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153) An unknown compound, L, has the formula C5H10O2. Elucidate the structure of L by
scrutinizing its IR, 1H NMR and 13C NMR spectra, shown below.
Answer: O
Methyl butyrate
154) An unknown compound, I, has the formula C3H7NO2. Elucidate the structure of I by
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scrutinizing its IR, 1H NMR and 13C NMR spectra, shown below.
Answer: NO2
1-Nitropropane
155) An unknown compound, E, has the formula C6H12O. Elucidate the structure of E by
scrutinizing its IR, 1H NMR and 13C NMR spectra, shown below.
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Answer:
2-Hexanone
156) An unknown compound, U, has the formula C6H4Cl2O. Elucidate the structure of U by
scrutinizing its IR, 1H NMR and 13C NMR spectra, shown below.
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OH
Cl Cl
Answer:
2,6-dichlorophenol
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157) Explain the key differences in the 2-dimensional NMR techniques known as COSY and
heteronuclear correlations.
Answer: A COSY shows correlations between two proton signals, whereas heteronuclear
correlation is designed to show interactions between protons and other non-proton atoms such as
carbon.
158) An unknown compound, V, has the formula C8H10O. Elucidate the structure of V by
scrutinizing its IR, 1H NMR and 13C NMR spectra, shown below.
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OH
Answer:
2,6-dimethylphenol
159) In mass spectrometry, the most intense peak is assigned an intensity of 100%, and is
referred to as the ___.
161) In electron impact mass spectrometry, a beam of high-energy electrons initially dislodges
one electron from the compound being studied. This produces a positively charged ion called the
___.
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162) What can be determined from the relative abundance of the M +1 peak?
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