Question 1

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1000-1250 cm−1 (strong) , but does not have peaks 3200-3650 at 1630-1820 or cm−1?

Accepted Answer

A)   alcohol
B)   aldehyde or ketone
C)   ether
D)   ester

Question 2

Provide the structure of four compounds with the molecular formula C5H10O which give a strong absorption peak at 1700-1740 cm-1 in the infrared spectrum, but no significant peaks at 1600-1640 cm-1 .

Accepted Answer

Any four o...

Question 3

MATCH each of the following groups of bond-types to the region of the infrared spectrum in which their absorptions occur. Place the letter of the region in the blank to the left of the bond-type.
-_____ N−H, C−H, and O−H stretching and bending motions.

Accepted Answer

A)  4000 to 2500 cm−1
B)  2500 to 2000 cm−1
C)  2000 to 1500 cm−1
D)  below 1500 cm−1

Question 4

The area in the infrared spectrum between 1400 and 400 cm-1 is called the functional group region.

Accepted Answer

A) True 
 B)False

Question 5

The "n" values for ethanol and carbon dioxide are given below. The total numbers of fundamental vibrations observed in ethanol and carbon dioxide are _____ and _____, respectively. ​
Molecule
CH3CH2OH
CO2
N
5
3

Accepted Answer

A)   21; 3
B)   21; 4
C)   20; 4
D)   20; 3

Question 6

MATCH a structure from the list below to the following IR spectra. Place the letter of the structure in the blank provided.
-_____  Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/

Accepted Answer

A)  
B)  
C)  
D)  
E)  F)

Question 7

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

Accepted Answer

A)   sp3 C − sp3 C
B)   alkene sp2 C − sp2 C
C)   arene sp2 C − sp2 C
D)   C≡C

Question 8

A C=O bond undergoes stretching at a lower frequency than C=C.

Accepted Answer

A) True 
 B)False

Question 9

The vertical axis on an IR spectrum represents the percent transmission and the horizontal axis measures frequency (wavenumber).

Accepted Answer

A) True 
 B)False

Question 10

Which of the following bonds (circled)  vibrates at the highest frequency?

Accepted Answer

A)   1
B)   2
C)   3
D)   4

Question 11

Which of the following processes takes place upon absorption of infrared radiation?

Accepted Answer

A)   bond vibration
B)   electron excitation
C)   nuclear spin flip
D)   electron spin flip

Question 12

What is the wavenumber of a radiation with a wavelength of 5.0 × 10−5 m?

Accepted Answer

A)   2.0 × 106 cm−1
B)   2.0 × 104 cm−1
C)   2.1 × 103 cm−1
D)   2.2 × 105 cm−1

Question 13

The given molecule shows two absorption peaks, each at 1760 cm−1 and 1810 cm−1. The peaks are due to the _____. ​ −1 and 1810 cm−1. The peaks are due to the _____. ​   A)  symmetric and unsymmetric bending vibrations of the entire anhydride group B)  symmetric stretching vibration of only one carbonyl group C)  unsymmetric stretching vibrations of the carbonyl groups D)  symmetric and unsymmetric stretching vibrations of the entire anhydride group" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   symmetric and unsymmetric bending vibrations of the entire anhydride group
B)   symmetric stretching vibration of only one carbonyl group
C)   unsymmetric stretching vibrations of the carbonyl groups
D)   symmetric and unsymmetric stretching vibrations of the entire anhydride group

Question 14

What is required for a bond to give an infrared absorption?

Accepted Answer

A)   a change in bond length during vibration
B)   a change in bond angle during vibration
C)   a change in bond dipole during vibration
D)   a change in reduced mass during vibration

Question 15

Provide a brief explanation to account for the observation that 1-butyne gives a significantly stronger peak at ∼1250 cm-1 in the infrared spectrum than 2-butyne..

Accepted Answer

2-Butyne is a symmetrical mole...

Question 16

Examining the infrared spectrum of a compound allows us to determine the nature of the conjugated pi electron system in the compound.

Accepted Answer

A) True 
 B)False

Question 17

Assume you are carrying out the conversion of 1-bromobutane to 1-butanol. How could you use IR spectroscopy to determine when the reaction is complete?  As the reaction progress the 3400−3640 cm−1 IR band should increase in intensity.

Accepted Answer

A) True 
 B)False

Question 18

What are the units of wavenumber,  vˉ\bar vvˉ  , in infrared spectroscopy?

Accepted Answer

A)   cm
B)   cm?1
C)   J?mol?1
D)   none, wavenumber is a dimensionless quantity

Question 19

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1630-1820 cm−1 (strong, broad)  and 1000-1250 cm−1; but does not have peaks at 3200-3650 cm−1?

Accepted Answer

A)   alcohol
B)   aldehyde or ketone
C)   ether
D)   ester

Question 20

Which of the following compounds gives an infrared spectrum with peaks at 3000-3500 cm−1 and ∼1750 cm−1? ​ 1 and ∼1750 cm−1? ​   ​ A)  1 B)  2 C)  3 D)  4" class="answers-bank-image d-inline" rel="preload" > ​

Accepted Answer

A)   1
B)   2
C)   3
D)   4

Exam 12: Infrared Spectroscopy

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1630-1820 cm−1 (strong, broad) and 1000-1250 cm−1; but does not have peaks at 3200-3650 cm−1?

Correct AnswerverifiedShow Answer

MATCH each of the following groups of bond-types to the region of the infrared spectrum in which their absorptions occur. Place the letter of the region in the blank to the left of the bond-type. -_____ N−H, C−H, and O−H stretching and bending motions.

Correct AnswerverifiedShow Answer

Which of the following bonds (circled) vibrates at the highest frequency?

Correct AnswerverifiedShow Answer

The area in the infrared spectrum between 1400 and 400 cm-1 is called the functional group region.

Correct AnswerverifiedShow Answer

The "n" values for ethanol and carbon dioxide are given below. The total numbers of fundamental vibrations observed in ethanol and carbon dioxide are _____ and _____, respectively. ​ Molecule CH3CH2OH CO2 N 5 3

Correct AnswerverifiedShow Answer

Provide the structure of four compounds with the molecular formula C5H10O which give a strong absorption peak at 1700-1740 cm-1 in the infrared spectrum, but no significant peaks at 1600-1640 cm-1 .

Correct AnswerverifiedAny four o...View AnswerShow Answer

A C=O bond undergoes stretching at a lower frequency than C=C.

Correct AnswerverifiedShow Answer

The given molecule shows two absorption peaks, each at 1760 cm−1 and 1810 cm−1. The peaks are due to the _____. ​

Correct AnswerverifiedShow Answer

Assume you are carrying out the conversion of 1-bromobutane to 1-butanol. How could you use IR spectroscopy to determine when the reaction is complete? As the reaction progress the 3400−3640 cm−1 IR band should increase in intensity.

Correct AnswerverifiedShow Answer

What are the units of wavenumber, vˉ\bar vvˉ , in infrared spectroscopy?

Correct AnswerverifiedShow Answer

Provide a brief explanation to account for the observation that 1-butyne gives a significantly stronger peak at ∼1250 cm-1 in the infrared spectrum than 2-butyne..

Correct Answerverified2-Butyne is a symmetrical mole...View AnswerShow Answer

Which of the following compounds gives an infrared spectrum with peaks at 3000-3500 cm−1 and ∼1750 cm−1? ​ ​

Correct AnswerverifiedShow Answer

Which of the following processes takes place upon absorption of infrared radiation?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

What is the wavenumber of a radiation with a wavelength of 5.0 × 10−5 m?

Correct AnswerverifiedShow Answer

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1000-1250 cm−1 (strong) , but does not have peaks 3200-3650 at 1630-1820 or cm−1?

Correct AnswerverifiedShow Answer

What is required for a bond to give an infrared absorption?

Correct AnswerverifiedShow Answer

The vertical axis on an IR spectrum represents the percent transmission and the horizontal axis measures frequency (wavenumber).

Correct AnswerverifiedShow Answer

Examining the infrared spectrum of a compound allows us to determine the nature of the conjugated pi electron system in the compound.

Correct AnswerverifiedShow Answer

MATCH a structure from the list below to the following IR spectra. Place the letter of the structure in the blank provided. -_____ Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/

Correct AnswerverifiedShow Answer

Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1630-1820 cm−¹ (strong, broad) and 1000-1250 cm−¹; but does not have peaks at 3200-3650 cm−¹?

Correct Answer
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Correct Answer
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The area in the infrared spectrum between 1400 and 400 cm^-1 is called the functional group region.

Correct Answer
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The "n" values for ethanol and carbon dioxide are given below. The total numbers of fundamental vibrations observed in ethanol and carbon dioxide are _ and _, respectively. Molecule CH₃CH₂OH CO₂ N 5 3

Correct Answer
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Provide the structure of four compounds with the molecular formula C₅H₁₀O which give a strong absorption peak at 1700-1740 cm^-1 in the infrared spectrum, but no significant peaks at 1600-1640 cm^-1 .

Correct Answer
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Any four o...
View Answer

Correct Answer
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The given molecule shows two absorption peaks, each at 1760 cm⁻¹ and 1810 cm⁻¹. The peaks are due to the _____.

Correct Answer
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Assume you are carrying out the conversion of 1-bromobutane to 1-butanol. How could you use IR spectroscopy to determine when the reaction is complete? As the reaction progress the 3400−3640 cm−¹ IR band should increase in intensity.

Correct Answer
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What are the units of wavenumber, $\bar v$ , in infrared spectroscopy?

Correct Answer
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Provide a brief explanation to account for the observation that 1-butyne gives a significantly stronger peak at ∼1250 cm^-1 in the infrared spectrum than 2-butyne..

Correct Answer
verified
2-Butyne is a symmetrical mole...
View Answer

Which of the following compounds gives an infrared spectrum with peaks at 3000-3500 cm−¹ and ∼1750 cm−¹?

Correct Answer
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Correct Answer
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Correct Answer
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What is the wavenumber of a radiation with a wavelength of 5.0 × 10⁻⁵ m?

Correct Answer
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Which of the following functional groups is likely to be present in a molecule that has peaks in the infrared spectrum at 1000-1250 cm−¹ (strong) , but does not have peaks 3200-3650 at 1630-1820 or cm−¹?

Correct Answer
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Correct Answer
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