Question 1

Which of the following is the base peak in the mass spectrum of 2,2,4-trimethylpentane?

Accepted Answer

A)  114 
B)  57 
C)  42 
D)  29 
E)  none of these 
A)  114 
B)  57 
C)  42 
D)  29 
E)  none of these

Question 2

Rank absorption of the indicated bonds in decreasing (highest to lowest) order of wavenumber.

Accepted Answer

A)  III > II > I 
B)  I > II > III 
C)  II > I > III 
D)  III > I > II 
E)  II > III > I 
A)  III > II > I 
B)  I > II > III 
C)  II > I > III 
D)  III > I > II 
E)  II > III > I

Question 3

Which of the following alkene groups will produce the strongest signal?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
A)  I 
B)  II 
C)  III 
D)  IV

Question 4

Propose possible structure(s) for a compound with molecular formula C4H7N that shows absorption at 2250 cm-1 in its IR spectrum.

Accepted Answer

CH₃CH₂CH₂C≡N

Question 5

Which of the following information is primarily obtained from UV-VIS spectroscopy?

Accepted Answer

A)  arrangement of carbon and hydrogen atoms in a compound 
B)  molecular weight of a compound 
C)  any conjugated π system present in a compound 
D)  functional groups present in a compound 
E)  all of these 
A)  arrangement of carbon and hydrogen atoms in a compound 
B)  molecular weight of a compound 
C)  any conjugated π system present in a compound 
D)  functional groups present in a compound 
E)  all of these

Question 6

Which of the following compounds will have the lowest wavenumber for the carbonyl absorption?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 7

Which of the following alkene groups will produce the stronger signal? Explain why.

Accepted Answer

Compound I.
The more electrone

Question 8

How can you distinguish between cyclohexanol and cyclohexanecarboxylic acid using IR spectroscopy?

Accepted Answer

The OH absorption for the carb

Question 9

Calculate the degree of unsaturation for C11H8ClBrO.

Accepted Answer

A)  4 
B)  6 
C)  7 
D)  8 
E)  10 
A)  4 
B)  6 
C)  7 
D)  8 
E)  10

Question 10

For the following pair of compounds the expected stretching absorption of the C=O bond is 1685 cm-1 and 1715 cm-1 respectively. Explain using both words and structural drawings.

Accepted Answer

Compound I has a conjugated do

Question 11

Which of the following compounds will show two absorptions, one at 2700 cm-1 and one at 2800 cm-1, along with the carbonyl absorption?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 12

Which one of the following compounds is consistent with the following IR spectrum?   SDBS: National Institute of Advanced Industrial Science and Technology

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  V 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  V

Question 13

Absorption of _______ radiation results in vibrational excitation of the bonds in a compound.

Accepted Answer

A)  UV 
B)  Microwave 
C)  IR 
D)  Visible 
E)  x-ray 
A)  UV 
B)  Microwave 
C)  IR 
D)  Visible 
E)  x-ray

Question 14

For which of the following compounds will the (M+2)+• peak intensity be around one third the intensity of the molecular ion peak?

Accepted Answer

A)  CH3CH2CH2Br 
B)  CH3CH2CH2OH 
C)  CH3CH2CH2Cl 
D)  CH3CH2CH2NH2 
E)  none of these 
A)  CH3CH2CH2Br 
B)  CH3CH2CH2OH 
C)  CH3CH2CH2Cl 
D)  CH3CH2CH2NH2 
E)  none of these

Question 15

Which of the following bonds has the strongest absorption?

Accepted Answer

A)  C=N 
B)  C≡C 
C)  C=O 
D)  sp2 C-H 
E)  C-O 
A)  C=N 
B)  C≡C 
C)  C=O 
D)  sp2 C-H 
E)  C-O

Exam 14: Infrared Spectroscopy and Mass Spectrometry

Which of the following is the base peak in the mass spectrum of 2,2,4-trimethylpentane?

Rank absorption of the indicated bonds in decreasing (highest to lowest) order of wavenumber.

Which of the following alkene groups will produce the strongest signal?

Propose possible structure(s) for a compound with molecular formula C4H7N that shows absorption at 2250 cm-1 in its IR spectrum.

Which of the following information is primarily obtained from UV-VIS spectroscopy?

Which of the following compounds will have the lowest wavenumber for the carbonyl absorption?

Which of the following alkene groups will produce the stronger signal? Explain why.

How can you distinguish between cyclohexanol and cyclohexanecarboxylic acid using IR spectroscopy?

Calculate the degree of unsaturation for C11H8ClBrO.

For the following pair of compounds the expected stretching absorption of the C=O bond is 1685 cm-1 and 1715 cm-1 respectively. Explain using both words and structural drawings.

Which of the following compounds will show two absorptions, one at 2700 cm-1 and one at 2800 cm-1, along with the carbonyl absorption?

Which one of the following compounds is consistent with the following IR spectrum? SDBS: National Institute of Advanced Industrial Science and Technology

Absorption of _______ radiation results in vibrational excitation of the bonds in a compound.

For which of the following compounds will the (M+2)+• peak intensity be around one third the intensity of the molecular ion peak?

Which of the following bonds has the strongest absorption?

A Review of General Chemistry: Electrons, Bonds, and Molecular Properties

Molecular Representations

Acids and Bases

Alkanes and Cycloalkanes

Stereoisomerism

Chemical Reactivity and Mechanisms

Alkyl Halides: Nucleophilic Substitution and Elimination Reactions

Addition Reactions of Alkenes

Alkynes

Radical Reactions

Synthesis

Alcohols and Phenols

Ethers and Epoxides; Thiols and Sulfides

Nuclear Magnetic Resonance Spectroscopy

Conjugated Pi Systems and Pericyclic Reactions

Aromatic Compounds

Aromatic Substitution Reactions

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Alpha Carbon Chemistry: Enols and Enolates

Amines

Introduction to Organometallic Compounds

Carbohydrates

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

Propose possible structure(s) for a compound with molecular formula C₄H₇N that shows absorption at 2250 cm^-1 in its IR spectrum.

Calculate the degree of unsaturation for C₁₁H₈ClBrO.

For the following pair of compounds the expected stretching absorption of the C=O bond is 1685 cm^-1and 1715 cm^-1 respectively. Explain using both words and structural drawings.

Which of the following compounds will show two absorptions, one at 2700 cm^-1 and one at 2800 cm^-1, along with the carbonyl absorption?

For which of the following compounds will the (M+2)⁺• peak intensity be around one third the intensity of the molecular ion peak?