Question 1

he amount of energy in infrared light corresponds to the amount of energy needed to increase certain molecular motions, such as bond vibrations, in organic molecules.

Accepted Answer

A) True 
 B)False

Question 2

Which of the following compounds gives a carbonyl bond absorption at the highest frequency?

Accepted Answer

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

Question 3

Which of the following compounds gives an infrared spectrum with peaks at 3300 cm−1 (sharp peak) and 2150 cm−1 (sharp peak)?

Accepted Answer

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

Question 4

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)  visible 
A)  radio waves 
B)  ultraviolet 
C)  infrared 
D)  visible

Question 5

Which of the following bonds gives the weakest peak in the infrared spectrum for a stretching vibration?

Accepted Answer

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

Question 6

What is the energy of a photon moving with a frequency of 10.0 × 1010 s−1? (Planck's constant = 6.626 × 10−34 J s)

Accepted Answer

A)  6.626 × 10−23 J 
B)  6.626 × 10−22 J 
C)  66.26 × 10−23 J 
D)  66.26 × 10−25 J 
A)  6.626 × 10−23 J 
B)  6.626 × 10−22 J 
C)  66.26 × 10−23 J 
D)  66.26 × 10−25 J

Question 7

Cyclohexene and 2-hexyne both have the molecular formula C6H10. Any of the following regions of an IR spectrum could be used to distinguish these two compounds.
3020-3100 cm−1
 2100-2260 cm−1
1650-1670 cm−1

Accepted Answer

A) True 
 B)False

Question 8

An IR spectrum of an unknown organic molecule having the formula which contains carbon, hydrogen, and oxygen reveals a strong absorption at 1715-1725 cm-1. This molecule is most likely an ether.

Accepted Answer

A) True 
 B)False

Question 9

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C5H10O2)?
​

Accepted Answer

O-H: 3000-3600 cm^-1 C-

Question 10

Which of the following compounds gives an infrared spectrum with peaks at 1000-1250 cm−1 (strong), but does not have peaks at 3200-3650 or 1630-1820 cm−1 (sharp, weak peak)?

Accepted Answer

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

Question 11

What is the frequency of a radiation with a wavelength of 3.0 × 10−5 m? (Speed of light = 3.0 × 108 m/s)

Accepted Answer

A)  1 × 1013 Hz 
B)  2 × 1013 Hz 
C)  1.1 × 1013 Hz 
D)  1.2 × 1013 Hz 
A)  1 × 1013 Hz 
B)  2 × 1013 Hz 
C)  1.1 × 1013 Hz 
D)  1.2 × 1013 Hz

Question 12

Which of the following bonds gives rise to an absorbance at approximately 2700-3300 cm−1 in the infrared spectrum?

Accepted Answer

A)  C≡C 
B)  C=O 
C)  C=C 
D)  C−H 
A)  C≡C 
B)  C=O 
C)  C=C 
D)  C−H

Question 13

Which of the following compounds gives a carbonyl bond absorption at the lowest frequency?

Accepted Answer

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

Question 14

Which of the following relationships is not valid as applied to infrared spectroscopy?

Accepted Answer

A)  wavenumber = 1/λ (in cm) 
B)  ΔE = h ν 
C)  ΔE = λ ν 
D)  ν = 4.12 √(K/μ) 
A)  wavenumber = 1/λ (in cm) 
B)  ΔE = h ν 
C)  ΔE = λ ν 
D)  ν = 4.12 √(K/μ)

Exam 12: Infrared Spectroscopy

he amount of energy in infrared light corresponds to the amount of energy needed to increase certain molecular motions, such as bond vibrations, in organic molecules.

Which of the following compounds gives a carbonyl bond absorption at the highest frequency?

Which of the following compounds gives an infrared spectrum with peaks at 3300 cm−1 (sharp peak) and 2150 cm−1 (sharp peak)?

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

Which of the following bonds gives the weakest peak in the infrared spectrum for a stretching vibration?

What is the energy of a photon moving with a frequency of 10.0 × 1010 s−1? (Planck's constant = 6.626 × 10−34 J s)

Cyclohexene and 2-hexyne both have the molecular formula C6H10. Any of the following regions of an IR spectrum could be used to distinguish these two compounds. 3020-3100 cm−1 2100-2260 cm−1 1650-1670 cm−1

An IR spectrum of an unknown organic molecule having the formula which contains carbon, hydrogen, and oxygen reveals a strong absorption at 1715-1725 cm-1. This molecule is most likely an ether.

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C5H10O2)? ​

Which of the following compounds gives an infrared spectrum with peaks at 1000-1250 cm−1 (strong), but does not have peaks at 3200-3650 or 1630-1820 cm−1 (sharp, weak peak)?

What is the frequency of a radiation with a wavelength of 3.0 × 10−5 m? (Speed of light = 3.0 × 108 m/s)

Which of the following bonds gives rise to an absorbance at approximately 2700-3300 cm−1 in the infrared spectrum?

Which of the following compounds gives a carbonyl bond absorption at the lowest frequency?

Which of the following relationships is not valid as applied to infrared spectroscopy?

Covalent Bonding and Shapes of Molecules

Alkanes and Cycloalkanes

Stereoisomerism and Chirality

Acids and Bases

Alkenes: Bonding, Nomenclature, and Properties

Reactions of Alkenes

Alkynes

Haloalkanes, Halogenation, and Radical Reactions

Nucleophilic Substitution and Beta-Elimination

Alcohols

Ethers, Epoxides, and Sulfides

Nuclear Magnetic Resonance Spectroscopy

Mass Spectrometry

An Introduction to Organometallic Compounds

Aldehydes and Ketones

Carboxylic Acids

Functional Derivatives of Carboxylic Acids

Enolate Anions and Enamines

Dienes, Conjugated Systems, and Pericyclic Reactions

Benzene and the Concept of Aromaticity

Reactions of Benzene and Its Derivatives

Amines

Catalytic Carbon-Carbon Bond Formation

Carbohydrates

Lipids

Amino Acids and Proteins

Nucleic Acids

Organic Polymer Chemistry

Filters

Which of the following compounds gives an infrared spectrum with peaks at 3300 cm−¹ (sharp peak) and 2150 cm−¹ (sharp peak)?

What is the energy of a photon moving with a frequency of 10.0 × 10¹⁰ s⁻¹? (Planck's constant = 6.626 × 10⁻³⁴ J s)

Cyclohexene and 2-hexyne both have the molecular formula C₆H₁₀. Any of the following regions of an IR spectrum could be used to distinguish these two compounds. 3020-3100 cm−¹ 2100-2260 cm−¹ 1650-1670 cm−¹

An IR spectrum of an unknown organic molecule having the formula which contains carbon, hydrogen, and oxygen reveals a strong absorption at 1715-1725 cm^-1. This molecule is most likely an ether.

Label three peaks in the following spectrum with the bond that gives rise to them, and identify the functional group that is present in the compound (the compound has a formula of C₅H₁₀O₂)?

Which of the following compounds gives an infrared spectrum with peaks at 1000-1250 cm−¹ (strong), but does not have peaks at 3200-3650 or 1630-1820 cm−¹ (sharp, weak peak)?

What is the frequency of a radiation with a wavelength of 3.0 × 10⁻⁵ m? (Speed of light = 3.0 × 10⁸ m/s)

Which of the following bonds gives rise to an absorbance at approximately 2700-3300 cm−¹ in the infrared spectrum?