Question 1

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$\equiv$C 
A) sp3 C -sp3 C 
B) alkene sp2 C - sp2 C 
C) arene sp2 C - sp2 C 
D) C$\equiv$C

Question 2

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 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.
-_____ C-C, C-O, C-N, and C-X single-bond vibrations.

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 
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

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), but does not have peaks at 3200-3650 or 1000-1250 cm-1

Accepted Answer

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

Question 5

The region of the IR spectrum between 1500 - 400 cm-1 would be significantly different for the following two substances?

Accepted Answer

A) True 
 B)False

Question 6

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 7

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.
-_____ C=O, C=N, and C=C bond absorptions.

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

Question 8

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

Question 9

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 10

Which of the following bonds (circled) gives a very weak or no stretching absorption in the infrared spectrum?

Accepted Answer

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

Question 11

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 
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 12

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 13

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 14

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 15

In terms of the electromagnetic spectrum, 2870 cm-1represents lower energy than 2.91 * 1016 Hz.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following regions in the electromagnetic spectrum corresponds to the radiation with the longest wavelength?

Accepted Answer

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

Question 17

Which of the following bonds gives rise to a medium strength absorbance at approximately 1600-1680 cm-1 in the infrared spectrum?

Accepted Answer

A) C-H 
B) C-C 
C) C=C 
D) C$\equiv$C 
A) C-H 
B) C-C 
C) C=C 
D) C$\equiv$C

Question 18

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of N,N-dimethylacetamide, CH3CON(CH3)2, is higher than that of methyl acetate, CH3CO2CH3.

Accepted Answer

The C=O bond of the amide is weaker than

Question 19

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of 2-butanone is higher than that of 3-buten-2-one.

Accepted Answer

The C=O bond of 3-buten-2-one

Question 20

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

Exam 12: Infrared Spectroscopy

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

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

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. -_____ C-C, C-O, C-N, and C-X single-bond vibrations.

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), but does not have peaks at 3200-3650 or 1000-1250 cm-1

The region of the IR spectrum between 1500 - 400 cm-1 would be significantly different for the following two substances?

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 .

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. -_____ C=O, C=N, and C=C bond absorptions.

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/

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.

Which of the following bonds (circled) gives a very weak or no stretching absorption in the infrared spectrum?

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

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..

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?

In terms of the electromagnetic spectrum, 2870 cm-1represents lower energy than 2.91 * 1016 Hz.

Which of the following regions in the electromagnetic spectrum corresponds to the radiation with the longest wavelength?

Which of the following bonds gives rise to a medium strength absorbance at approximately 1600-1680 cm-1 in the infrared spectrum?

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of N,N-dimethylacetamide, CH3CON(CH3)2, is higher than that of methyl acetate, CH3CO2CH3.

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of 2-butanone is higher than that of 3-buten-2-one.

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

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

The region of the IR spectrum between 1500 - 400 cm^-1 would be significantly different for the following two substances?

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 .

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.

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..

In terms of the electromagnetic spectrum, 2870 cm^-¹represents lower energy than 2.91 * 10¹⁶ Hz.

Which of the following bonds gives rise to a medium strength absorbance at approximately 1600-1680 cm^-¹ in the infrared spectrum?

Provide a brief explanation to account for the observation that the frequency of the C=O stretching absorption in the infrared spectrum of N,N-dimethylacetamide, CH₃CON(CH₃)₂, is higher than that of methyl acetate, CH₃CO₂CH₃.