Question 1

Which of the following is not prominent in the mass spectrum of 2-methyl-2-butanol?

Accepted Answer

A) M - 15 
B) M - 18 
C) M - 21 
D) M - 29 
A) M - 15 
B) M - 18 
C) M - 21 
D) M - 29 B

Question 2

Which of the following sets of molecular ions does an alkyl chloride possess?

Accepted Answer

A) two molecular ions in a 2:1 ratio separated by two mass units 
B) two molecular ions in a 1:1 ratio separated by two mass units 
C) three molecular ions in a 1:2:1 ratio separated by two mass units 
D) two molecular ions in a 3:1 ratio separated by two mass units 
A) two molecular ions in a 2:1 ratio separated by two mass units 
B) two molecular ions in a 1:1 ratio separated by two mass units 
C) three molecular ions in a 1:2:1 ratio separated by two mass units 
D) two molecular ions in a 3:1 ratio separated by two mass units D

Question 3

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 60?

Accepted Answer

A) 1-hexanol 
B) 2-hexanol 
C) hexanal 
D) hexanoic acid 
A) 1-hexanol 
B) 2-hexanol 
C) hexanal 
D) hexanoic acid D

Question 4

What are products of the collision between high energy electrons and methane?

Accepted Answer

A) CH41- + 2 e- 
B) CH3-. + H. 
C) CH4+S1. + 2 e- 
D) CH3.+ H+ + 2 e- 
A) CH41- + 2 e- 
B) CH3-. + H. 
C) CH4+S1. + 2 e- 
D) CH3.+ H+ + 2 e-

Question 5

Mass spectrometry and infrared spectroscopy are complementary techniques because mass spectrometry provides information about the molar mass and formula while infrared spectroscopy helps identify the functional groups in the formula.

Accepted Answer

A) True 
 B)False

Question 6

Provide the mass of the three most prominent fragment peaks that are observed in the EI mass spectrum of methyl pentanoate, CH3CH2CH2CH2CO2CH3 (molecular ion m/z = 116) and describe the processes that lead to each of these fragments.

Accepted Answer

88: loss of CH₂=CH₂ (28) by McLa

Question 7

What is the y-axis of a mass spectrum?

Accepted Answer

A) mass 
B) energy 
C) abundance 
D) field strength 
A) mass 
B) energy 
C) abundance 
D) field strength

Question 8

Which of the following gives rise to a prominent peak in the mass spectrum at m/z of 39?

Accepted Answer

A) 1-octyne 
B) 4-octyne 
C) 5-methyl-3-octyne 
D) 2,2-dimethyl-3-heptyne 
A) 1-octyne 
B) 4-octyne 
C) 5-methyl-3-octyne 
D) 2,2-dimethyl-3-heptyne

Question 9

Which C5H12O compound give the following EI mass spectrum?

Accepted Answer

Question 10

Which of the molecules gives rise to a molecular ion with an odd value of m/z?

Accepted Answer

A) C6H12O2 
B) C7H10ClN 
C) C8H18N2 
D) C8H12 
A) C6H12O2 
B) C7H10ClN 
C) C8H18N2 
D) C8H12

Question 11

How many carbon atoms are present in a molecule which gives an M+1 peak that is 11.48% of the intensity of the molecular ion?

Accepted Answer

A) 5 
B) 6 
C) 11 
D) 12 
A) 5 
B) 6 
C) 11 
D) 12

Question 12

What is the x-axis of a mass spectrum?

Accepted Answer

A) mass 
B) mass/energy 
C) mass/charge 
D) charge 
A) mass 
B) mass/energy 
C) mass/charge 
D) charge

Question 13

Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s).   Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/
-Dehydration of the following compound will produce a peak at a m/z of _______.

Accepted Answer

The answer of Refer to the mass spectrum of 2-methylbutane...

Question 14

Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s).   Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/
-The peak at a m/z of _____ represents the base peak.

Accepted Answer

The answer of Refer to the mass spectrum of 2-methylbutane...

Question 15

What is the most likely molecular formula of a compound that has a molecular ion in the EI mass spectrum with m/z of 120, with a M+1 and M+2 peaks that are 6.6% and 24% of the intensity of the molecular ion peak, respectively.

Accepted Answer

The answer of What is the most likely molecular formula...

Question 16

What is the most likely molecular formula of a compound (that contains only C, H and O) which has a molecular ion in the EI mass spectrum with m/z of 104 and an M+1 peak that is 5.5% of the intensity of the molecular ion peak?

Accepted Answer

The answer of What is the most likely molecular formula...

Question 17

What is the most likely molecular formula of a compound that has a molecular ion in the EI mass spectrum with m/z of 136, with a M+1 and M+2 peaks that are 4.4% and 49% of the intensity of the molecular ion peak, respectively.

Accepted Answer

The answer of What is the most likely molecular formula...

Question 18

Which of the following bonds of the octane radical cation is least subject to fragmentation?

Accepted Answer

A) i 
B) ii 
C) iii 
D) iv 
A) i 
B) ii 
C) iii 
D) iv

Question 19

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 30?

Accepted Answer

A) 1-hexanamine, CH3CH2CH2CH2CH2CH2NH2 
B) 1,1-dimethyl-1-butanamine, CH3CH2CH2C(CH3)2NH2 
C) 1-hexanol 
D) hexanal 
A) 1-hexanamine, CH3CH2CH2CH2CH2CH2NH2 
B) 1,1-dimethyl-1-butanamine, CH3CH2CH2C(CH3)2NH2 
C) 1-hexanol 
D) hexanal

Question 20

Which C6H12O carbonyl-containing compound shows a molecular ion peak at m/z 100 and significant fragment peaks at m/z 85, 58, 57, 43 and 42 in the EI mass spectrum?

Accepted Answer

4-methyl-2

Exam 14: Mass Spectrometry

Which of the following is not prominent in the mass spectrum of 2-methyl-2-butanol?

Which of the following sets of molecular ions does an alkyl chloride possess?

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 60?

What are products of the collision between high energy electrons and methane?

Mass spectrometry and infrared spectroscopy are complementary techniques because mass spectrometry provides information about the molar mass and formula while infrared spectroscopy helps identify the functional groups in the formula.

Provide the mass of the three most prominent fragment peaks that are observed in the EI mass spectrum of methyl pentanoate, CH3CH2CH2CH2CO2CH3 (molecular ion m/z = 116) and describe the processes that lead to each of these fragments.

What is the y-axis of a mass spectrum?

Which of the following gives rise to a prominent peak in the mass spectrum at m/z of 39?

Which C5H12O compound give the following EI mass spectrum?

Which of the molecules gives rise to a molecular ion with an odd value of m/z?

How many carbon atoms are present in a molecule which gives an M+1 peak that is 11.48% of the intensity of the molecular ion?

What is the x-axis of a mass spectrum?

Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/ -Dehydration of the following compound will produce a peak at a m/z of _______.

Refer to the mass spectrum of 2-methylbutane shown below to answer the following question(s). Spectrum obtained from: SDBSWeb: http://www.aist.go.jp/RIODB/SDBS/ -The peak at a m/z of _____ represents the base peak.

What is the most likely molecular formula of a compound that has a molecular ion in the EI mass spectrum with m/z of 120, with a M+1 and M+2 peaks that are 6.6% and 24% of the intensity of the molecular ion peak, respectively.

What is the most likely molecular formula of a compound (that contains only C, H and O) which has a molecular ion in the EI mass spectrum with m/z of 104 and an M+1 peak that is 5.5% of the intensity of the molecular ion peak?

What is the most likely molecular formula of a compound that has a molecular ion in the EI mass spectrum with m/z of 136, with a M+1 and M+2 peaks that are 4.4% and 49% of the intensity of the molecular ion peak, respectively.

Which of the following bonds of the octane radical cation is least subject to fragmentation?

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 30?

Which C6H12O carbonyl-containing compound shows a molecular ion peak at m/z 100 and significant fragment peaks at m/z 85, 58, 57, 43 and 42 in the EI mass spectrum?

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

Infrared Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

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

Provide the mass of the three most prominent fragment peaks that are observed in the EI mass spectrum of methyl pentanoate, CH₃CH₂CH₂CH₂CO₂CH₃ (molecular ion m/z = 116) and describe the processes that lead to each of these fragments.

Which C₅H₁₂O compound give the following EI mass spectrum?

Which C₆H₁₂O carbonyl-containing compound shows a molecular ion peak at m/z 100 and significant fragment peaks at m/z 85, 58, 57, 43 and 42 in the EI mass spectrum?