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49.
Which one of the following compounds is consistent with the following IR spectrum?
SDBS: National Institute of Advanced Industrial Science and Technology
OH
O
OH
O
OH
III III IV
OH
V
OH
A)
I
B)
II
C)
III
D)
IV
E)
V
50.
Which one of the following compounds is consistent with the following IR spectrum?
SDBS: National Institute of Advanced Industrial Science and Technology
NH2
CH3
NHCH3NH2NH2
CH3
CH3
N(CH3)2
III III IV V
A)
I
B)
II
C)
III
D)
IV
E)
V
51.
For the following reaction, which of the following is consistent with the IR spectrum of
the product?
CN
+
O H
1. DIBAH
A)
absorption at 2250 cm-1 should disappear
B)
absorption at 3200-3400 cm-1 and 1720cm-1 should appear
C)
absorption at 2250 cm-1 should disappear, new absorption at 2600-2800 cm-1 and 1720
cm-1 should appear.
D)
absorption at 2250 cm-1 should disappear and absorption around 3400 cm-1 should
appear.
E)
none of these
52.
For the following reaction, which of the following is consistent with the IR spectrum of
the product?
H3O+
O
A)
absorption at 2150 cm-1 should disappear
B)
absorption at 3300 cm-1 and 2150cm-1 should disappear
C)
absorption at 2250 cm-1 should disappear, new absorption at 3300 cm-1 should appear
D)
absorption at 1650 cm-1 should disappear and absorption at 3300 cm-1 should appear
E)
absorption at 3300 cm-1 and 2150cm-1 should disappear, a new absorption at 1720 cm-1
should appear
53.
For the following reaction, which of the following is consistent with the IR spectrum of
the product?
1. NaH
OH OCH2CH3
2. CH3CH2Br
A)
absorption at 3200-3600 cm-1 should disappear
B)
absorption at 3200-3600 cm-1 and 1100 cm-1 should disappear
C)
absorption at 1100 cm-1 should disappear and absorption at 3100 cm-1 should appear
D)
absorption at 1650 cm-1 should disappear and absorption at 3300 cm-1 should appear.
E)
none of these
54.
Predict the product for the following reaction and explain how you will use IR
spectroscopy to monitor the progress of the reaction.
1-pentyne 1. NaNH2
2. CH3CH2Br
55.
Predict the product for the following reaction and explain how you will use IR
spectroscopy to monitor the progress of the reaction.
1. CH3CH2MgBr
2. H2O
O
56.
Mass spectrometry is primarily used to determine:
A)
molecular formula of a compound
B)
molecular weight of a compound
C)
conjugation in a compound
D)
A & B
E)
A & C
57.
Which of the following is initially produced when a compound is bombarded with high
energy electrons?
A)
anion
B)
free radical
C)
radical cation
D)
cation
E)
none of these
58.
Which of the following is not true about the molecular ion in mass spectrometry?
A)
The molecular ion is produced by loss of one electron from the molecule.
B)
The mass of the molecular ion is equivalent to the mass of the molecule.
C)
The ion is produced by a loss of pair of electrons from the molecule.
D)
The molecular ion is often unstable and can undergo fragmentation.
E)
none of these
59.
Which of the following is always true about the base peak in a mass spectrum?
A)
peak corresponding to molecular ion
B)
peak corresponding to the most abundant ion
C)
peak corresponding to lowest m/z
D)
A & C
E)
none of these
60.
The separation of ions in the mass spectrometer is done by their ______.
A)
electrons to protons ratio
B)
mass to neutrons ratio
C)
protons to neutrons ratio
D)
mass to charge ratio
E)
none of these
61.
Which of the following is true about CH3CH3+•?
A)
it is the parent ion of ethane
B)
it is a molecular ion of ethane with m/z =30
C)
it is a fragment of propane
D)
A & B
E)
none of these
62.
Which of the m/z values corresponds to the base peak in the following mass spectrum?
A)
45
B)
44
C)
29
D)
15
E)
none of these
63.
Which of the m/z values correspond to the molecular ion peak in the following mass
spectrum?
A)
45
B)
44
C)
29
D)
15
E)
none of these
64.
Which of the m/z values correspond to the molecular ion for the following compound?
OH
A)
18
B)
82
C)
100
D)
102
E)
103
65.
Which of the following compounds will have odd m/z value for the molecular ion?
H
O
H N
O
N
N
Br
Br
III III IV
A)
I
B)
II
C)
III
D)
IV
E)
none of these
66.
Which of the following is true about the molecular weight and the M+•-m/z value for the
following compound?
NH2
Cl
A)
odd molecular weight, m/z-115
B)
odd molecular weight, m/z-121
C)
even molecular weight, m/z-96
D)
even molecular weight, m/z-132
E)
none of these
67.
Which of the following is true about the (M+1)+• peak on the mass spectrum of a
hydrocarbon?
A)
it is the most abundant peak
B)
it is due to the 13C isotope of carbon
C)
it has a m/z value lower than the molecular ion
D)
it is useful in calculating number of carbon atoms
E)
B & D
68.
Which molecular formula is consistent with the following mass spectrum data?
M+• at m/z= 84, relative height=10.0%
(M+1)+• at m/z= 85, relative height=0.56%
A)
C5H10O
B)
C5H8O
C)
C5H24
D)
C6H12
E)
C4H6O2
69.
Which molecular formula is consistent with the following mass spectrum data?
M+• at m/z= 72, relative height=73.0%
(M+1)+• at m/z= 73, relative height=3.3%
A)
C4H10O
B)
C4H9N
C)
C5H12
D)
C4H8O
E)
none of these
70.
Provide a molecular formula that is consistent with the following mass spectrum data.
M+• at m/z= 73, relative height=86.1%
(M+1)+• at m/z= 74, relative height=3.2%
71.
Provide a molecular formula that is consistent with the following mass spectrum data.
M+• at m/z= 136, relative height=65.6%
(M+1)+• at m/z= 137, relative height=6.2%
72.
Provide a molecular formula that is consistent with the following mass spectrum data.
M+• at m/z= 167, relative height=50.0%
(M+1)+• at m/z= 168, relative height=4.4%
73.
Compounds containing chlorine or bromine usually show a strong _____peak.
A)
molecular ion
B)
base
C)
M+1
D)
M+2
E)
all of these
74.
Which of the following will produce M+• and (M+2)+• peaks of equal intensity?
A)
nitrogen
B)
chlorine
C)
bromine
D)
oxygen
E)
B & C
75.
Presence of bromine produces M+• and (M+2)+• peaks of equal intensity on a mass
spectrum because:
A)
81Br isotope has higher natural abundance than 79Br isotope
B)
79Br and 81Br isotopes have almost equal natural abundance
C)
79Br isotope has higher natural abundance than 81Br isotope
D)
none of these
76.
Which molecular formula is consistent with the following mass spectrum data?
M+• at m/z= 78, relative height=23.5%
(M+1)+• at m/z= 79, relative height=0.78%
(M+2)+• at m/z= 80, relative height=7.5%
A)
C6H6
B)
C3H7Cl
C)
C6H8
D)
C6H9Cl
E)
none of these
77.
Which molecular formula is consistent with the following mass spectrum data?
M+• at m/z= 108, relative height=61.5%
(M+1)+• at m/z= 109, relative height=1.5%
(M+2)+• at m/z= 110, relative height=61.3%
A)
C2H5Br
B)
C5H12Cl
C)
C8H12
D)
C2H7Br
E)
none of these
78.
For which of the following compounds will the (M+2)+• peak intensity be around 25%
of the intensity of the molecular ion peak?
A)
CH3CH2CH2Br
B)
CH3CH2CH2OH
C)
CH3CH2CH2Cl
D)
CH3CH2CH2NH2
E)
none of these
79.
Which of the following mass spectra shows the presence of bromine in a compound?
I II
III IV
Four spectra above: courtesy of SDBS: National Institute of Advanced Industrial Science and Technology
A)
I
B)
II
C)
III
D)
IV
E)
none of these
