Question 1

Which of the following does not involve the interaction of molecules with electromagnetic energy?

Accepted Answer

A)  mass spectrometry
B)  infrared spectroscopy
C)  ultraviolet spectroscopy
D)  nuclear magnetic resonance spectroscopyE) A) and B)
F) None of the above

Question 2

Which of the following statements best describes the base peak in a mass spectrum?

Accepted Answer

A)  The peak from the most stable radical.
B)  The peak from the species that has the isotope with the highest atomic number.
C)  The peak of highest intensity.
D)  The peak from the molecule minus an electron.
E)  The M +1 peakF) C) and E)
G) A) and E)

Question 3

What are the units for electromagnetic radiation used in infrared spectroscopy?

Accepted Answer

A)  cm
B)  cm-1
C)  J.mol-1
D)  none,wavenumber is a dimensionless quantityE) A) and B)
F) A) and C)

Question 4

Match a structure from the list below to the following IR spectra.
-

Accepted Answer

The answer of Match a structure from the list below...

Question 5

Cyclohexene and hex-2-yne both have the molecular formula,C6H10.
a)How would you use infrared spectroscopy to distinguish between the two compounds?
b)How could the mass spectrum be used to distinguish between the two compounds?

Accepted Answer

Question 6

A 3.42 ´ 10-5 M solution of dibenzalacetone in ethanol produced an absorbance of 0.753 in a 1.00 cm cell.Based on this data,what is e for this compound?

Accepted Answer

A)  2.57 ´ 105
B)  2.20 ´ 104
C)  4.54 ´ 10-5
D)  2.92 ´ 104E) All of the above
F) A) and B)

Question 7

Which of the following bonds gives rise to a strong absorbance near 1700 cm-1 in the infrared spectrum?

Accepted Answer

A)  C=O
B)  C-O
C)  C=C
D)  C-CE) All of the above
F) A) and D)

Question 8

Instructions: Select the most reasonable formula for the compounds with the following mass spectral data.
Refer to instructions.M+ at m/z = 101

Accepted Answer

A)  C5H6Br
B)  C5H12N2
C)  C6H15N
D)  C9H12OE) B) and C)
F) None of the above

Question 9

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s).
 
(Spectrum obtained from:SDBSWeb:http://www.aist.go.jp/RIODB/SDBS/)

-Refer to instructions.Propose structures for fragment ions at m/z = 57,43,and 29.

Accepted Answer

The answer of Instructions: Refer to the mass spectrum of...

Question 10

What is the horizontal axis of a mass spectrum?

Accepted Answer

A)  mass
B)  mass/energy
C)  mass/charge
D)  chargeE) A) and C)
F) B) and C)

Question 11

Consider the compound below: 
a)At what approximate positions might the compound show IR absorptions? 	 
b)How would this spectrum differ from that of cyclohexanol?

Accepted Answer

The answer of Consider the compound below: 
a)At what approximate...

Question 12

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s).
 
(Spectrum obtained from:SDBSWeb:http://www.aist.go.jp/RIODB/SDBS/)

-Refer to instructions.What peak represents the base peak?

Accepted Answer

The peak a...

Question 13

Which of the following peaks is not prominent in the mass spectrum of 2-methylbutan-2-ol?

Accepted Answer

A)  M+ - 15
B)  M+ - 18
C)  M+ - 21
D)  M+ - 29E) B) and C)
F) None of the above

Question 14

At what approximate positions might the compound below show IR absorptions?

Accepted Answer

This compound should show a me...

Question 15

Instructions: Select the most reasonable formula for the compounds with the following mass spectral data.
Refer to instructions.M+ at m/z = 216

Accepted Answer

A)  C6H13OCl
B)  C4H8Br2
C)  C10H16
D)  C9H12OE) A) and D)
F) A) and C)

Question 16

The amount of energy in infrared light corresponds to:

Accepted Answer

A)  the amount of energy needed to promote one electron from a bonding to an antibonding molecular orbital
B)  the amount of energy needed to fragment a molecule
C)  the amount of energy needed to strip a molecule of one electron to generate a cation radical
D)  the amount of energy needed to increase certain molecular motions,such as bond vibrations,in organic moleculesE) All of the above
F) None of the above

Question 17

What are the masses of the charged fragments produced by the dehydration of the following compound?

Accepted Answer

This compound has the formula ...

Question 18

Which of the following regions in the electromagnetic spectrum corresponds to the radiation with the highest energy?

Accepted Answer

A)  radio waves
B)  ultraviolet
C)  infrared
D)  visibleE) A) and D)
F) All of the above

Question 19

Which of the following compounds gives an infrared spectrum with a peak at ~1750 cm-1,but no significant peaks at 3000-3500 cm-1 or 1050-1250 cm-1?

Accepted Answer

A)   -1,but no significant peaks at 3000-3500 cm-1 or 1050-1250 cm-1? 
A)     
B)     
C)     
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B)   -1,but no significant peaks at 3000-3500 cm-1 or 1050-1250 cm-1? 
A)     
B)     
C)     
D)    " class="answers-bank-image d-inline" rel="preload" >
C)   -1,but no significant peaks at 3000-3500 cm-1 or 1050-1250 cm-1? 
A)     
B)     
C)     
D)    " class="answers-bank-image d-inline" rel="preload" >
D)   -1,but no significant peaks at 3000-3500 cm-1 or 1050-1250 cm-1? 
A)     
B)     
C)     
D)    " class="answers-bank-image d-inline" rel="preload" >E) A) and B)
F) A) and C)

Question 20

Which of the following bonds undergoes stretching at the highest frequency?

Accepted Answer

A)  O-H
B)  C-H
C)  C=O
D)  CºCE) A) and B)
F) A) and D)

Exam 10: Structure Determination: Mass Spectrometry,infrared Spectroscopy,and Ultraviolet Spectroscopy

Instructions: Select the most reasonable formula for the compounds with the following mass spectral data. Refer to instructions.M+ at m/z = 216

Correct AnswerverifiedShow Answer

At what approximate positions might the compound below show IR absorptions?

Correct AnswerverifiedThis compound should show a me...View AnswerShow Answer

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). (Spectrum obtained from:SDBSWeb:http://www.aist.go.jp/RIODB/SDBS/) -Refer to instructions.What peak represents the base peak?

Correct AnswerverifiedThe peak a...View AnswerShow Answer

Which of the following does not involve the interaction of molecules with electromagnetic energy?

Correct AnswerverifiedShow Answer

Which of the following bonds gives rise to a strong absorbance near 1700 cm-1 in the infrared spectrum?

Correct AnswerverifiedShow Answer

The amount of energy in infrared light corresponds to:

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Which of the following statements best describes the base peak in a mass spectrum?

Correct AnswerverifiedShow Answer

Cyclohexene and hex-2-yne both have the molecular formula,C6H10. a)How would you use infrared spectroscopy to distinguish between the two compounds? b)How could the mass spectrum be used to distinguish between the two compounds?

Correct AnswerverifiedShow Answer

What are the masses of the charged fragments produced by the dehydration of the following compound?

Correct AnswerverifiedThis compound has the formula ...View AnswerShow Answer

Which of the following peaks is not prominent in the mass spectrum of 2-methylbutan-2-ol?

Correct AnswerverifiedShow Answer

Instructions: Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). (Spectrum obtained from:SDBSWeb:http://www.aist.go.jp/RIODB/SDBS/) -Refer to instructions.Propose structures for fragment ions at m/z = 57,43,and 29.

Correct AnswerverifiedShow Answer

Which of the following compounds gives an infrared spectrum with a peak at ~1750 cm-1,but no significant peaks at 3000-3500 cm-1 or 1050-1250 cm-1?

Correct AnswerverifiedShow Answer

Which of the following bonds undergoes stretching at the highest frequency?

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Consider the compound below: a)At what approximate positions might the compound show IR absorptions? b)How would this spectrum differ from that of cyclohexanol?

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What is the horizontal axis of a mass spectrum?

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Which of the following regions in the electromagnetic spectrum corresponds to the radiation with the highest energy?

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Instructions: Select the most reasonable formula for the compounds with the following mass spectral data. Refer to instructions.M+ at m/z = 101

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Match a structure from the list below to the following IR spectra. -

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What are the units for electromagnetic radiation used in infrared spectroscopy?

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A 3.42 ´ 10-5 M solution of dibenzalacetone in ethanol produced an absorbance of 0.753 in a 1.00 cm cell.Based on this data,what is e for this compound?

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Instructions: Select the most reasonable formula for the compounds with the following mass spectral data. Refer to instructions.M⁺ at m/z = 216

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This compound should show a me...
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The peak a...
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Which of the following bonds gives rise to a strong absorbance near 1700 cm^-1 in the infrared spectrum?

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Cyclohexene and hex-2-yne both have the molecular formula,C₆H₁₀. a)How would you use infrared spectroscopy to distinguish between the two compounds? b)How could the mass spectrum be used to distinguish between the two compounds?

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This compound has the formula ...
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Which of the following compounds gives an infrared spectrum with a peak at ~1750 cm^-1,but no significant peaks at 3000-3500 cm^-1 or 1050-1250 cm^-1?

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Instructions: Select the most reasonable formula for the compounds with the following mass spectral data. Refer to instructions.M⁺ at m/z = 101

Correct Answer
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Correct Answer
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Correct Answer
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A 3.42 ´ 10^-5 M solution of dibenzalacetone in ethanol produced an absorbance of 0.753 in a 1.00 cm cell.Based on this data,what is e for this compound?

Correct Answer
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