Question 1

Which of the following wavenumber corresponds to the C=O double bond region on an IR spectrum?

Accepted Answer

A)  1500 - 4000 cm-1 
B)  400 - 4000 cm-1 
C)  400 - 1500 cm-1 
D)  2100 - 2300 cm-1 
E)  1600 - 1850 cm-1 
A)  1500 - 4000 cm-1 
B)  400 - 4000 cm-1 
C)  400 - 1500 cm-1 
D)  2100 - 2300 cm-1 
E)  1600 - 1850 cm-1

Question 2

Which molecular formula is consistent with the following mass spectral data? M+• at m/z = 108, relative height = 61.5%
(M+1)+• at m/z = 109, relative height = 1.5%
(M+2)+• at m/z = 110, relative height = 61.3%

Accepted Answer

A)  C2H5Br 
B)  C5H12Cl 
C)  C8H12 
D)  C2H7Br 
E)  none of these 
A)  C2H5Br 
B)  C5H12Cl 
C)  C8H12 
D)  C2H7Br 
E)  none of these

Question 3

Mass spectrometry is primarily used to determine:

Accepted Answer

A)  molecular formula of a compound 
B)  molecular weight of a compound 
C)  conjugation in a compound 
D)  A and B 
E)  A and C 
A)  molecular formula of a compound 
B)  molecular weight of a compound 
C)  conjugation in a compound 
D)  A and B 
E)  A and C

Question 4

Following are the IR spectrum and mass spectrum of an unknown compound. Propose a structure for the unknown compound.     SDBS:

Accepted Answer

The answer of Following are the IR spectrum and mass...

Question 5

Provide a molecular formula that is consistent with the following mass spectral data.
M+• at m/z = 136, relative height = 65.6%
(M+1)+ • at m/z = 137, relative height = 6.2%

Accepted Answer

Question 6

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

Accepted Answer

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

Question 7

Calculate the degree of unsaturation for C9H11N.

Accepted Answer

A)  4 
B)  6 
C)  2 
D)  5 
E)  3 
A)  4 
B)  6 
C)  2 
D)  5 
E)  3

Question 8

Predict the product for the following reaction and explain how you can use IR spectroscopy to monitor the progress of the reaction.

Accepted Answer

@#IMG-DLM&_TB4454_00 A new abs

Question 9

In mass spectrometry using the electron impact ionization technique, a beam of high-energy electrons initially ejects one electron from the compound being studied. This produces a positively charged ion called the ____________________.

Accepted Answer

The answer of In mass spectrometry using the electron impact...

Question 10

Calculate the degree of unsaturation for C14H14N2O.

Accepted Answer

A)  4 
B)  6 
C)  8 
D)  10 
E)  9 
A)  4 
B)  6 
C)  8 
D)  10 
E)  9

Question 11

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

Accepted Answer

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

Question 12

Which of the m/z values correspond to the molecular ion for the following compound?

Accepted Answer

A)  18 
B)  82 
C)  100 
D)  102 
E)  103 
A)  18 
B)  82 
C)  100 
D)  102 
E)  103

Question 13

Provide a molecular formula that is consistent with the following mass spectral data.
M+• at m/z = 167, relative height = 50.0%
(M+1)+ • at m/z = 168, relative height = 4.4%

Accepted Answer

Question 14

Which of the following vibrations are observed in IR spectroscopy?

Accepted Answer

A)  stretching 
B)  rotational 
C)  bending 
D)  A and B 
E)  A and C 
A)  stretching 
B)  rotational 
C)  bending 
D)  A and B 
E)  A and C

Question 15

Which of the following is always true about the base peak in a mass spectrum?

Accepted Answer

A)  the peak corresponding to molecular ion 
B)  the peak corresponding to the most abundant ion 
C)  the peak corresponding to lowest m/z 
D)  the peak corresponding to the cation 
E)  the peak corresponding to the lowest fragment 
A)  the peak corresponding to molecular ion 
B)  the peak corresponding to the most abundant ion 
C)  the peak corresponding to lowest m/z 
D)  the peak corresponding to the cation 
E)  the peak corresponding to the lowest fragment

Question 16

For the following reaction, which of the following change(s) in the IR spectrum is consistent with conversion of the reactant to the product?

Accepted Answer

A)  absorption at 3300 - 3400 cm-1 should disappear 
B)  absorption at 3300 - 3400 cm-1 and 1100 cm-1 should disappear 
C)  absorption at 1100 cm-1 should disappear, a new absorption at 3100 cm-1 should appear 
D)  absorption at 1650 cm-1 should disappear, a new absorption at 3300 cm-1 should appear. 
E)  absorption at 3300 - 3400 cm-1 should appear 
A)  absorption at 3300 - 3400 cm-1 should disappear 
B)  absorption at 3300 - 3400 cm-1 and 1100 cm-1 should disappear 
C)  absorption at 1100 cm-1 should disappear, a new absorption at 3100 cm-1 should appear 
D)  absorption at 1650 cm-1 should disappear, a new absorption at 3300 cm-1 should appear. 
E)  absorption at 3300 - 3400 cm-1 should appear

Question 17

In mass spectrometry, the tallest peak is assigned an intensity of 100% and is referred to as the ______________.

Accepted Answer

The answer of In mass spectrometry, the tallest peak is...

Question 18

Which of the following information is primarily obtained from nuclear magnetic resonance 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 19

Which of the following electromagnetic radiation has the highest frequency?

Accepted Answer

A)  UV 
B)  X-ray 
C)  IR 
D)  microwave 
E)  visible 
A)  UV 
B)  X-ray 
C)  IR 
D)  microwave 
E)  visible

Question 20

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

Accepted Answer

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

Exam 14: Infrared Spectroscopy and Mass Spectrometry

Which of the following wavenumber corresponds to the C=O double bond region on an IR spectrum?

Which molecular formula is consistent with the following mass spectral data? M+• at m/z = 108, relative height = 61.5% (M+1)+• at m/z = 109, relative height = 1.5% (M+2)+• at m/z = 110, relative height = 61.3%

Mass spectrometry is primarily used to determine:

Following are the IR spectrum and mass spectrum of an unknown compound. Propose a structure for the unknown compound. SDBS:

Provide a molecular formula that is consistent with the following mass spectral data. M+• at m/z = 136, relative height = 65.6% (M+1)+ • at m/z = 137, relative height = 6.2%

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

Calculate the degree of unsaturation for C9H11N.

Predict the product for the following reaction and explain how you can use IR spectroscopy to monitor the progress of the reaction.

In mass spectrometry using the electron impact ionization technique, a beam of high-energy electrons initially ejects one electron from the compound being studied. This produces a positively charged ion called the ____________________.

Calculate the degree of unsaturation for C14H14N2O.

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

Which of the m/z values correspond to the molecular ion for the following compound?

Provide a molecular formula that is consistent with the following mass spectral data. M+• at m/z = 167, relative height = 50.0% (M+1)+ • at m/z = 168, relative height = 4.4%

Which of the following vibrations are observed in IR spectroscopy?

Which of the following is always true about the base peak in a mass spectrum?

For the following reaction, which of the following change(s) in the IR spectrum is consistent with conversion of the reactant to the product?

In mass spectrometry, the tallest peak is assigned an intensity of 100% and is referred to as the ______________.

Which of the following information is primarily obtained from nuclear magnetic resonance spectroscopy?

Which of the following electromagnetic radiation has the highest frequency?

Which of the following compounds will have the highest wavenumber for carbonyl 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

Which molecular formula is consistent with the following mass spectral data? M⁺•at m/z = 108, relative height = 61.5% (M+1)⁺•at m/z = 109, relative height = 1.5% (M+2)⁺•at m/z = 110, relative height = 61.3%

Provide a molecular formula that is consistent with the following mass spectral data. M⁺•at m/z = 136, relative height = 65.6% (M+1)⁺ •at m/z = 137, relative height = 6.2%

Calculate the degree of unsaturation for C₉H₁₁N.

Calculate the degree of unsaturation for C₁₄H₁₄N₂O.

Provide a molecular formula that is consistent with the following mass spectral data. M⁺•at m/z = 167, relative height = 50.0% (M+1)⁺ •at m/z = 168, relative height = 4.4%