51.
Determine the multiplicity of each signal in the expected 1H NMR spectrum of the
following compound.
O
52.
Determine the multiplicity of each signal in the expected 1H NMR spectrum of the
following compound.
N
H
O
53.
Determine the multiplicity of each signal in the expected 1H NMR spectrum of the
following compound.
O
O
54.
Determine the multiplicity of each signal in the expected 1H NMR spectrum of the
following compound.
O
H
O
55.
Determine the multiplicity of each signal in the expected 1H NMR spectrum of the
following compound.
O NH2
HO
O
56.
Determine the multiplicity of each signal in the expected 1H NMR spectrum of 2,3-
dimethyl-2-pentanol.
57.
The coupling constant (J) for bromoethane is 7 Hz when the 1H NMR spectrum is
acquired 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
E)
none of these
Ans:
B
58.
Which of the following is the maximum multiplicity observed for Hc protons in the
following compound? Assume that Jcd and Jcb values are different.
H
N
ab
c
d
A)
5
B)
6
C)
8
D)
12
E)
none of these
59.
Which of the following is the maximum multiplicity observed for Hb protons in the
following compound? Assume that Jab and Jbc values are different.
O
a
a
b
cd
A)
9
B)
12
C)
21
D)
24
E)
none of these
Ans:
C
60.
Presence of which of the following protons is confirmed by D2O exchange?
A)
OH
B)
NH2
C)
CH
D)
A & B
E)
none of these
Ans:
D
Ans:
D
61.
Determine the multiplicity and predict the chemical shifts of each signal in the expected
1H NMR spectrum of the following compound.
O
O
III
I
62.
Determine the multiplicity and predict the chemical shifts of each signal in the expected
1H NMR spectrum of the following compound.
O
OO
63.
Determine the multiplicity and predict the chemical shifts of each signal in the expected
1H NMR spectrum of the following compound.
O
O
64.
How would you use 1H NMR spectroscopy to distinguish between the following two
compounds?
H
O
O
H
O O
III
A)
I=3 & II=2 signals
B)
I=4 & II=3 signals
C)
I=5 & II=3 signals
D)
none of these
Ans:
B
65.
How would you use 1H NMR spectroscopy to distinguish between the following two
compounds?
III
O O
O O
66.
How would you use 1H NMR spectroscopy to distinguish between the following two
compounds?
O
O
III
O
O
67.
How would you use 1H NMR spectroscopy to distinguish between the following two
compounds?
O
O
O
O
III
68.
A compound with a molecular formula C9H12 has the following 1H NMR spectrum.
Which of the following structures is consistent with this spectrum?
01234567
PPM
9
3
III III IV
A)
I
B)
II
C)
III
D)
IV
E)
none of these
Ans:
C
69.
Which of the following structures is consistent with this 1H NMR spectrum?
SDBS: National Institute of Advanced Industrial Science and Technology
OO O
III III IV
A)
I
B)
II
C)
III
D)
IV
E)
none of these
1
1
5
3
Ans:
B
70.
A compound with a molecular formula C9H10O2 has the following 1H NMR spectrum.
Which of the following structures is consistent with this spectrum?
H
O
O
OH
O
O
III III IV
A)
I
B)
II
C)
III
D)
IV
E)
none of these
0
2
4
6
8
10
12
PPM
Ans:
B
71.
A compound with a molecular formula C5H10O has the following 1H NMR spectrum.
Propose a structure for this compound.
0246810
PPM
72.
Propose a structure for a compound with molecular formula C5H11Cl, that fits the
following spectroscopic data:
1H NMR: 0.9 (triplet, I=3), 1.3 (sextet, I=2), 1.5 (quartet, I=2), 1.6 (doublet, I=3),
3.6 (sextet, I=1)
9
1
73.
Propose a structure for a compound with molecular formula C8H14O3 that fits the
following spectroscopic data.
IR:1820cm-1, 1760cm-1
1H NMR: 1.0 (triplet, I=6), 1.6 (sextet, I=4), 2.2 (triplet, I=4)
74.
Propose a structure for a compound with molecular formula C10H12O that fits the
following spectroscopic data.
IR:1680cm-1
1H NMR: 1.0 (triplet, I=3), 1.5 (sextet, I=2), 2.6 (triplet, I=4), 7.4 (triplet, I=2),
7.5 (triplet, I=1), 7.9 (doublet, I=2)
75.
A compound with a molecular formula C8H16O has the following 1H NMR spectrum.
Provide a structure that is consistent with this spectrum?
0
1
2
PPM
1
2
2
2
6
3
76.
A compound with a molecular formula C10H12O2 has the following HNMR spectrum.
Which of the following structures is consistent with this spectrum?
CH
O
O
O
O
COH
O
COH
O
I
II III IV
A)
I
B)
II
C)
III
D)
IV
E)
none of these
0
1
2
3
4
5
6
7
8
9
10
11
PPM
1
2
2
2
2
3
Ans:
C
77.
How many signals would you expect to find in the 13C NMR spectrum of the following
compound?
O
A)
6
B)
7
C)
8
D)
9
E)
none of these
78.
How many signals would you expect to find in the 13C NMR spectrum of the following
compound?
OO
A)
2
B)
3
C)
4
D)
5
E)
none of these
Ans:
C
Ans:
B
79.
How many signals would you expect to find in the 13C NMR spectrum of the following
compound?
A)
6
B)
7
C)
8
D)
9
E)
none of these
80.
How many signals would you expect to find in the 13C NMR spectrum of the following
compounds?
O
O
Cl
CH2CH3
III
A)
I-5, II-8
B)
I-3, II-6
C)
I-4, II-8
D)
I-5, II-6
E)
none of these
Ans:
D
Ans:
D
81.
Which of the following carbon atoms will display the signal most downfield in the 13C
NMR spectrum?
CN
C
O
CC
F
C C
III III IV V
A)
I
B)
II
C)
III
D)
IV
E)
none of these
82.
Which of the following compounds will display four signals in the 13C NMR spectrum?
A)
2,6-dimethylheptane
B)
2,4-dimethylheptane
C)
3,5-dimethylheptane
D)
4,4-dimethylheptane
E)
none of these
Ans:
A
Ans:
B