Question 1

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 91?

Accepted Answer

A)  1-octene 
B)  1-hexanamine, CH3CH2CH2CH2CH2CH2NH2 
C)  benzene 
D)  ethylbenzene 
A)  1-octene 
B)  1-hexanamine, CH3CH2CH2CH2CH2CH2NH2 
C)  benzene 
D)  ethylbenzene D

Question 2

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 A

Question 3

Which of the following corresponds to the molecular ion in EI mass spectrometry?

Accepted Answer

A)  the most abundant ion 
B)  the ion with the smallest m/e 
C)  the ion formed by removal of an electron from the molecule 
D)  any ion formed by fragmentation of the molecule 
A)  the most abundant ion 
B)  the ion with the smallest m/e 
C)  the ion formed by removal of an electron from the molecule 
D)  any ion formed by fragmentation of the molecule C

Question 4

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of M - 31?

Accepted Answer

A)  2-methylhexanoic acid 
B)  methyl hexanoate 
C)  ethyl hexanoate 
D)  hexanoic acid 
A)  2-methylhexanoic acid 
B)  methyl hexanoate 
C)  ethyl hexanoate 
D)  hexanoic acid

Question 5

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

Accepted Answer

A)  C6H12Cl2 
B)  C7H10N2 
C)  C8H13N 
D)  C8H14Br2 
A)  C6H12Cl2 
B)  C7H10N2 
C)  C8H13N 
D)  C8H14Br2

Question 6

What is the most likely molecular formula of a compound that has a molecular ion in the EI mass spectrum with m/z of 97 and an M+1 peak that is 6.6% of the intensity of the molecular ion peak?

Accepted Answer

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

Question 7

Which of the following gives rise to a prominent M - 15 peak in the mass spectrum?

Accepted Answer

A)  hexane 
B)  1-chloropentane 
C)  1-pentanol 
D)  3-methylpentane 
A)  hexane 
B)  1-chloropentane 
C)  1-pentanol 
D)  3-methylpentane

Question 8

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

Accepted Answer

A)  M - 29 
B)  M - 18 
C)  M - 15 
D)  M - 12 
A)  M - 29 
B)  M - 18 
C)  M - 15 
D)  M - 12

Question 9

Which of the following is most consistent with a molecule having a molecular ion with m/e of 77?

Accepted Answer

A)  the molecule contains bromine 
B)  the molecule contains nitrogen 
C)  the molecule is an alcohol 
D)  the molecule is a hydrocarbon 
A)  the molecule contains bromine 
B)  the molecule contains nitrogen 
C)  the molecule is an alcohol 
D)  the molecule is a hydrocarbon

Question 10

What are the most common products of the fragmentation of a molecular ion?

Accepted Answer

A)  two radicals 
B)  an anion and a cation 
C)  a radical and a cation 
D)  two cations 
A)  two radicals 
B)  an anion and a cation 
C)  a radical and a cation 
D)  two cations

Question 11

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 41?

Accepted Answer

A)  1-hexene 
B)  2-hexyne 
C)  3-hexanol 
D)  2-chlorohexane 
A)  1-hexene 
B)  2-hexyne 
C)  3-hexanol 
D)  2-chlorohexane

Question 12

In mass spectrometry, which of the following phrases is shortened to the acronym "FAB"?

Accepted Answer

A)  flight averaged bumping 
B)  fast atom bombardment 
C)  fragmented atom beam 
D)  flying atom bashing 
A)  flight averaged bumping 
B)  fast atom bombardment 
C)  fragmented atom beam 
D)  flying atom bashing

Question 13

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 45?

Accepted Answer

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

Question 14

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 15

Which of the following gives rise to a prominent M - 18 peak in the mass spectrum?

Accepted Answer

A)  hexane 
B)  1-chloropentane 
C)  1-pentanol 
D)  3-methylpentane 
A)  hexane 
B)  1-chloropentane 
C)  1-pentanol 
D)  3-methylpentane

Question 16

How many carbon atoms are present in a molecule which gives an M+1 peak that is 5.74% 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 17

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 18

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

Question 19

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

Question 20

What is the most likely moleuclar 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 moleuclar formula...

Exam 14: Mass Spectrometry

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 91?

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

Which of the following corresponds to the molecular ion in EI mass spectrometry?

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of M - 31?

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

What is the most likely molecular formula of a compound that has a molecular ion in the EI mass spectrum with m/z of 97 and an M+1 peak that is 6.6% of the intensity of the molecular ion peak?

Which of the following gives rise to a prominent M - 15 peak in the mass spectrum?

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

Which of the following is most consistent with a molecule having a molecular ion with m/e of 77?

What are the most common products of the fragmentation of a molecular ion?

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 41?

In mass spectrometry, which of the following phrases is shortened to the acronym "FAB"?

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 45?

What is the y-axis of a mass spectrum?

Which of the following gives rise to a prominent M - 18 peak in the mass spectrum?

How many carbon atoms are present in a molecule which gives an M+1 peak that is 5.74% of the intensity of the molecular ion?

What is the x-axis of a mass spectrum?

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

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

What is the most likely moleuclar 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?

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

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