Question 1

A compound X shows a molecular ion peak at m/z 72 in its mass spectrum, and a strong peak at ~1715 cm-1 in its IR spectrum. Which structures are possible for compound X? -1 in its IR spectrum. Which structures are possible for compound X?   A)  I B)  II C)  III D)  I and II" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   I
B)   II
C)   III
D)   I and IIE) A) and D)
F) B) and C)

Question 2

Examine the IR below and classify the compound.

Accepted Answer

A)   Alcohol
B)   Aldehyde
C)   Amine
D)   KetoneE) B) and C)
F) A) and D)

Question 3

Examine the IR below and classify the compound.

Accepted Answer

A)   Alcohol
B)   Arene
C)   Amine
D)   Ketone
E)   Carbocylic acidF) A) and D)
G) A) and C)

Question 4

What type of feature will be observed in the EI mass spectrum of chlorobenzene?

Accepted Answer

A)   An absorption at 3100 cm-1
B)   A signal at 113.
C)   A signal at 112 and a signal at 114 in a ratio of 3:1
D)   A signal at 112 and a signal at 114 in a ratio of 1:1E) B) and D)
F) A) and D)

Question 5

When the phenol shown below is treated with KOH, it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm-1 region. Propose a structure for the product. -1 region. Propose a structure for the product.   A)  I B)  II C)  III D)  IV" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) B) and D)
F) A) and D)

Question 6

13C NMR is a technique in which the total number of signals represents the number of unique carbon atoms in a molecule. Propose a structure that is consistent with the following data. 
(a)  The IR includes peaks at 1603 and 1495 cm-1.
(b)  The 13C NMR has a total of 7 signals.
(c)  The compound has one acidic proton. 13C NMR is a technique in which the total number of signals represents the number of unique carbon atoms in a molecule. Propose a structure that is consistent with the following data.  (a)  The IR includes peaks at 1603 and 1495 cm-1. (b)  The 13C NMR has a total of 7 signals. (c)  The compound has one acidic proton.   A)  I B)  II C)  III D)  IV" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) A) and C)
F) B) and C)

Question 7

Which of the following statements is (are)  true about the IR spectrum of the compound drawn below? -1 and 1720 cm-1. B)  It shows absorptions at 3000-2850 cm-1 and 2150 cm-1. C)  It shows absorptions at 2250 cm-1 and 1650 cm-1. D)  It shows absorptions at 2250 cm-1 and 1720 cm-1. E)  Both statements B (It shows absorptions at 3000-2850 cm-1 and 2250 cm-1)  and D (It shows absorptions at 2250 cm-1 and 1720 cm-1)  are true." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   It shows absorptions at 3000-3150 cm-1 and 1720 cm-1.
B)   It shows absorptions at 3000-2850 cm-1 and 2150 cm-1.
C)   It shows absorptions at 2250 cm-1 and 1650 cm-1.
D)   It shows absorptions at 2250 cm-1 and 1720 cm-1.
E)   Both statements B (It shows absorptions at 3000-2850 cm-1 and 2250 cm-1)  and D (It shows absorptions at 2250 cm-1 and 1720 cm-1)  are true.F) None of the above
G) A) and B)

Question 8

What type of signal(s)  would you observe in the mass and (or)  infrared spectrum of the following compound? -1" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   A signal at 95 amu
B)   A signal at 94 amu
C)   Two signals at 95 and 94 amu
D)   A signal at 3600-3200 cm-1E) All of the above
F) None of the above

Question 9

In a typical mass spectrum, a smaller signal is observed at a mass 1 amu higher than the molecular ion peak. Why?

Accepted Answer

A)   Due to small impurities in the sample
B)   Machine error
C)   Because a small percentage of the compound will have a carbon that is the isotope 13C instead of 12C
D)   Because of fragmentationE) None of the above
F) C) and D)

Question 10

Which of the following compounds will have the lowest wavenumber for carbonyl absorption?

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) B) and D)
F) None of the above

Question 11

Which of the indicated C-H bonds absorbs at the lowest wave number in the IR spectrum?

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) None of the above
F) B) and D)

Question 12

Which of the following  bonds is IR inactive?  bonds is IR inactive?   A)  I B)  II C)  III D)  IV" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) B) and C)
F) A) and D)

Question 13

Examine the IR below and classify the compound.

Accepted Answer

A)   Alkane
B)   Carboxylic acid
C)   Alcohol
D)   AlkeneE) All of the above
F) A) and B)

Question 14

In electron impact mass spectrometry (EIMS) , what is being detected?

Accepted Answer

A)   The molecular mass of the compound
B)   The molecular formula of the compound
C)   The mass to charge ratio of any ionic species
D)   The mass to charge ratio of any neutral speciesE) A) and D)
F) A) and B)

Question 15

An alkyne C-H bond absorbs at higher wave number than an alkene C-H bond. What does this tell you about the strength of these two bonds?

Accepted Answer

A)   The alkene C-H bond is stronger.
B)   The alkyne C-H bond is stronger.
C)   The alkene C-C bond is stronger.
D)   The alkyne C-C bond is stronger.E) C) and D)
F) B) and D)

Question 16

Which of the following statements about the base peak of a mass spectrum is always true?

Accepted Answer

A)   The base peak corresponds to the molecular ion.
B)   The base peak corresponds to the most abundant ion.
C)   The base peak corresponds to the lowest m/z.
D)   None of the above.E) A) and B)
F) A) and C)

Question 17

What type(s)  of molecular motion is (are)  observed using infrared spectroscopy?

Accepted Answer

A)   Stretching and bending
B)   Rotation and excitation
C)   Spin flipping
D)   FragmentationE) B) and D)
F) B) and C)

Question 18

Which of the following statements is (are)  true about a compound that has a molecular ion peak in its mass spectrum at mass 94, and shows prominent peaks in its IR spectrum at 3600-3200 and 1600 cm-1?

Accepted Answer

A)   The compound has a molecular mass of 94.
B)   The compound contains a C=O group and Csp3-H hybridized bonds.
C)   The compound contains an OH group and a benzene ring.
D)   Both A (The compound has a molecular mass of 94)  and B (The compound contains a C=O group and Csp3-H hybridized bonds)  are true statements.
E)   Both A (The compound has a molecular mass of 94)  and C (The compound contains an OH group and a benzene ring)  are true statements.F) All of the above
G) B) and E)

Question 19

Compared to a C-H bond, a C-D bond will vibrate where in the infrared spectrum?

Accepted Answer

A)   Higher molecular weight
B)   Lower molecular weight
C)   Lower wavenumbers
D)   Higher wavenumbersE) None of the above
F) A) and B)

Question 20

An IR spectrum has the following potentially important absorptions: 3091, 3067, 2963, 2921, 2252, 1603, 1499, 1455, 1416, 1078, 1031, 941, 735, and 696 cm-1. Indicate which structure corresponds to the IR data. -1. Indicate which structure corresponds to the IR data.   A)  I B)  II C)  III D)  IV" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   I
B)   II
C)   III
D)   IVE) A) and B)
F) All of the above

Exam 13: Mass Spectrometry and Infrared Spectroscopy

Which of the following statements about the base peak of a mass spectrum is always true?

Correct Answer
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When the phenol shown below is treated with KOH, it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm^-1 region. Propose a structure for the product.

Correct Answer
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What type of signal(s) would you observe in the mass and (or) infrared spectrum of the following compound?

Correct Answer
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An alkyne C-H bond absorbs at higher wave number than an alkene C-H bond. What does this tell you about the strength of these two bonds?

Correct Answer
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Correct Answer
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Which of the following  bonds is IR inactive?

Correct Answer
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A compound X shows a molecular ion peak at m/z 72 in its mass spectrum, and a strong peak at ~1715 cm^-1in its IR spectrum. Which structures are possible for compound X?

Correct Answer
verified

Which of the indicated C-H bonds absorbs at the lowest wave number in the IR spectrum?

Correct Answer
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Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 94, and shows prominent peaks in its IR spectrum at 3600-3200 and 1600 cm^-1?

Correct Answer
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What type of feature will be observed in the EI mass spectrum of chlorobenzene?

Correct Answer
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Examine the IR below and classify the compound.

Correct Answer
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Examine the IR below and classify the compound.

Correct Answer
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What type(s) of molecular motion is (are) observed using infrared spectroscopy?

Correct Answer
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Which of the following compounds will have the lowest wavenumber for carbonyl absorption?

Correct Answer
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In electron impact mass spectrometry (EIMS) , what is being detected?

Correct Answer
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Compared to a C-H bond, a C-D bond will vibrate where in the infrared spectrum?

Correct Answer
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Examine the IR below and classify the compound.

Correct Answer
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Which of the following statements is (are) true about the IR spectrum of the compound drawn below?

Correct Answer
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In a typical mass spectrum, a smaller signal is observed at a mass 1 amu higher than the molecular ion peak. Why?

Correct Answer
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An IR spectrum has the following potentially important absorptions: 3091, 3067, 2963, 2921, 2252, 1603, 1499, 1455, 1416, 1078, 1031, 941, 735, and 696 cm^-¹. Indicate which structure corresponds to the IR data.

Correct Answer
verified

Exam 13: Mass Spectrometry and Infrared Spectroscopy

Which of the following statements about the base peak of a mass spectrum is always true?

Correct AnswerverifiedShow Answer

When the phenol shown below is treated with KOH, it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm-1 region. Propose a structure for the product.

Correct AnswerverifiedShow Answer

What type of signal(s) would you observe in the mass and (or) infrared spectrum of the following compound?

Correct AnswerverifiedShow Answer

An alkyne C-H bond absorbs at higher wave number than an alkene C-H bond. What does this tell you about the strength of these two bonds?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following  bonds is IR inactive?

Correct AnswerverifiedShow Answer

A compound X shows a molecular ion peak at m/z 72 in its mass spectrum, and a strong peak at ~1715 cm-1 in its IR spectrum. Which structures are possible for compound X?

Correct AnswerverifiedShow Answer

Which of the indicated C-H bonds absorbs at the lowest wave number in the IR spectrum?

Correct AnswerverifiedShow Answer

Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 94, and shows prominent peaks in its IR spectrum at 3600-3200 and 1600 cm-1?

Correct AnswerverifiedShow Answer

What type of feature will be observed in the EI mass spectrum of chlorobenzene?

Correct AnswerverifiedShow Answer

Examine the IR below and classify the compound.

Correct AnswerverifiedShow Answer

Examine the IR below and classify the compound.

Correct AnswerverifiedShow Answer

What type(s) of molecular motion is (are) observed using infrared spectroscopy?

Correct AnswerverifiedShow Answer

Which of the following compounds will have the lowest wavenumber for carbonyl absorption?

Correct AnswerverifiedShow Answer

In electron impact mass spectrometry (EIMS) , what is being detected?

Correct AnswerverifiedShow Answer

Compared to a C-H bond, a C-D bond will vibrate where in the infrared spectrum?

Correct AnswerverifiedShow Answer

Examine the IR below and classify the compound.

Correct AnswerverifiedShow Answer

Which of the following statements is (are) true about the IR spectrum of the compound drawn below?

Correct AnswerverifiedShow Answer

In a typical mass spectrum, a smaller signal is observed at a mass 1 amu higher than the molecular ion peak. Why?

Correct AnswerverifiedShow Answer

An IR spectrum has the following potentially important absorptions: 3091, 3067, 2963, 2921, 2252, 1603, 1499, 1455, 1416, 1078, 1031, 941, 735, and 696 cm-1. Indicate which structure corresponds to the IR data.

Correct AnswerverifiedShow Answer

Correct Answer
verified

When the phenol shown below is treated with KOH, it forms a product whose IR spectrum does not show an absorption in the 3200-3600 cm^-1 region. Propose a structure for the product.

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

A compound X shows a molecular ion peak at m/z 72 in its mass spectrum, and a strong peak at ~1715 cm^-1in its IR spectrum. Which structures are possible for compound X?

Correct Answer
verified

Correct Answer
verified

Which of the following statements is (are) true about a compound that has a molecular ion peak in its mass spectrum at mass 94, and shows prominent peaks in its IR spectrum at 3600-3200 and 1600 cm^-1?

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
verified

An IR spectrum has the following potentially important absorptions: 3091, 3067, 2963, 2921, 2252, 1603, 1499, 1455, 1416, 1078, 1031, 941, 735, and 696 cm^-¹. Indicate which structure corresponds to the IR data.

Correct Answer
verified