Question 1

At approximately what wavenumber does one expect to find the carbon-carbon triple bond stretch in the IR spectrum of an alkyne?

Accepted Answer

The answer of At approximately what wavenumber does one expect...

Question 2

Which of the following structures is consistent with the IR spectra shown below?

Accepted Answer

A)   
B)   
C)   
D)   
E)   F) A) and D)
G) B) and E)

Question 3

Absorption of what type of electromagnetic radiation results in electronic transitions?

Accepted Answer

A)   X-rays
B)   radio waves
C)   microwaves
D)   ultraviolet light
E)   infrared lightF) C) and E)
G) A) and D)

Question 4

Which region of the electromagnetic spectrum, IR or UV, contains photons of the higher energy?

Accepted Answer

The answer of Which region of the electromagnetic spectrum, IR...

Question 5

For toluene (shown below) , you would expect to see which m/z fragment in the mass spectrum?

Accepted Answer

A)   15
B)   43
C)   57
D)   You would expect to see all three fragments.E) All of the above
F) B) and C)

Question 6

Arrange the following regions of the electromagnetic spectrum in order of increasing wavelength: X ray, radio, UV, and IR.

Accepted Answer

X ray < UV...

Question 7

What IR absorption is characteristic of the O-H stretch in alcohols?

Accepted Answer

A)   4000 cm-1
B)   3300 cm-1
C)   2950 cm-1
D)   2250 cm-1
E)   1710 cm-1F) A) and B)
G) A) and C)

Question 8

The wavelength and frequency of a given wave of electromagnetic radiation are ________ proportional.

Accepted Answer

The answer of The wavelength and frequency of a given...

Question 9

Arrange the following IR bond stretches in order of increasing wavenumber:
C-O, C  
C, O-H, and C=C.

Accepted Answer

C-O < C <img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30"> C...

Question 10

The IR spectrum of a sample contains absorptions at 3050, 2950, and 1620 cm-1. To what class of organic compound does this sample most likely belong?

Accepted Answer

A)   alkane
B)   alkene
C)   alkyne
D)   ester
E)   alcoholF) A) and B)
G) C) and E)

Question 11

Which of the following would not have a C-H stretch at about 3050 cm-1?

Accepted Answer

A)   1-pentene
B)   2-pentene
C)   2-methyl-2-pentene
D)   2,3-dimethyl-2-pentene
E)   2,4-dimethyl-2-penteneF) A) and B)
G) C) and D)

Question 12

Which of the indicated bonds would be expected to have IR active frequencies?

Accepted Answer

A)   A only
B)   B only
C)   Both A and B
D)   Neither A nor BE) A) and C)
F) A) and D)

Question 13

Describe the molecular ion region in the mass spectrum of CH3CH2Br.

Accepted Answer

The natural abundance of the i...

Question 14

Describe the fate of a molecule from introduction to detection in a mass spectrometer.

Accepted Answer

Upon introduction, sample molecules are ...

Question 15

Which has the higher speed in a vacuum, ultraviolet or infrared light?

Accepted Answer

They have ...

Question 16

In addition to a carbonyl stretch, which of the following molecules exhibits two characteristic stretches at 2700 and 2800 cm-1?

Accepted Answer

A)   (CH3CH2) 2CO
B)   CH3CH2CH2CHO
C)   CH3CH2CO2CH3
D)   CH3CH2CH2CO2H
E)   CH3CH2CH2COClF) A) and E)
G) All of the above

Question 17

A nonlinear molecule with n atoms generally has ________ fundamental vibrational modes.

Accepted Answer

A)   2n
B)   2n - 2
C)   3n
D)   3n - 3
E)   3n - 6F) B) and D)
G) C) and E)

Question 18

Which compound has a strong and broad IR absorption centered at 3400 cm-1?

Accepted Answer

A)   1-butanol
B)   octane
C)   diethyl ether
D)   2-hexyne
E)   benzeneF) C) and E)
G) C) and D)

Question 19

Using IR, how could you tell if the reaction below was complete?

Accepted Answer

The peaks at 1600 and 3050 cm^-1 ...

Question 20

Explain the following observation regarding the IR stretching frequencies of the ketones shown below.

Accepted Answer

The stretching frequency of th...

Exam 12: Infrared Spectroscopy and Mass Spectrometry

Which has the higher speed in a vacuum, ultraviolet or infrared light?

Correct AnswerverifiedThey have ...View AnswerShow Answer

Describe the fate of a molecule from introduction to detection in a mass spectrometer.

Correct AnswerverifiedUpon introduction, sample molecules are ...View AnswerShow Answer

Using IR, how could you tell if the reaction below was complete?

Correct AnswerverifiedThe peaks at 1600 and 3050 cm-1 ...View AnswerShow Answer

The wavelength and frequency of a given wave of electromagnetic radiation are ________ proportional.

Correct AnswerverifiedShow Answer

The IR spectrum of a sample contains absorptions at 3050, 2950, and 1620 cm-1. To what class of organic compound does this sample most likely belong?

Correct AnswerverifiedShow Answer

Which of the indicated bonds would be expected to have IR active frequencies?

Correct AnswerverifiedShow Answer

Describe the molecular ion region in the mass spectrum of CH3CH2Br.

Correct AnswerverifiedThe natural abundance of the i...View AnswerShow Answer

Absorption of what type of electromagnetic radiation results in electronic transitions?

Correct AnswerverifiedShow Answer

Which compound has a strong and broad IR absorption centered at 3400 cm-1?

Correct AnswerverifiedShow Answer

Arrange the following regions of the electromagnetic spectrum in order of increasing wavelength: X ray, radio, UV, and IR.

Correct AnswerverifiedX ray < UV...View AnswerShow Answer

For toluene (shown below) , you would expect to see which m/z fragment in the mass spectrum?

Correct AnswerverifiedShow Answer

Arrange the following IR bond stretches in order of increasing wavenumber: C-O, C C, O-H, and C=C.

Correct AnswerverifiedC-O < C C...View AnswerShow Answer

Which of the following structures is consistent with the IR spectra shown below?

Correct AnswerverifiedShow Answer

In addition to a carbonyl stretch, which of the following molecules exhibits two characteristic stretches at 2700 and 2800 cm-1?

Correct AnswerverifiedShow Answer

What IR absorption is characteristic of the O-H stretch in alcohols?

Correct AnswerverifiedShow Answer

Explain the following observation regarding the IR stretching frequencies of the ketones shown below.

Correct AnswerverifiedThe stretching frequency of th...View AnswerShow Answer

Which region of the electromagnetic spectrum, IR or UV, contains photons of the higher energy?

Correct AnswerverifiedShow Answer

A nonlinear molecule with n atoms generally has ________ fundamental vibrational modes.

Correct AnswerverifiedShow Answer

At approximately what wavenumber does one expect to find the carbon-carbon triple bond stretch in the IR spectrum of an alkyne?

Correct AnswerverifiedShow Answer

Which of the following would not have a C-H stretch at about 3050 cm-1?

Correct AnswerverifiedShow Answer

Correct Answer
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They have ...
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Upon introduction, sample molecules are ...
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The peaks at 1600 and 3050 cm^-1 ...
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The IR spectrum of a sample contains absorptions at 3050, 2950, and 1620 cm^-1. To what class of organic compound does this sample most likely belong?

Correct Answer
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Correct Answer
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Describe the molecular ion region in the mass spectrum of CH₃CH₂Br.

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The natural abundance of the i...
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Correct Answer
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Which compound has a strong and broad IR absorption centered at 3400 cm^-1?

Correct Answer
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Correct Answer
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X ray < UV...
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Correct Answer
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C-O < C C...
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Correct Answer
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In addition to a carbonyl stretch, which of the following molecules exhibits two characteristic stretches at 2700 and 2800 cm^-1?

Correct Answer
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Correct Answer
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Correct Answer
verified
The stretching frequency of th...
View Answer

Correct Answer
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Correct Answer
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Correct Answer
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Which of the following would not have a C-H stretch at about 3050 cm^-1?

Correct Answer
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