Question 1

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

Accepted Answer

A)  mass analysis by light-detected ions 
B)  matrix assisted laser desorption ionization 
C)  many atom loss-detecting ionization 
D)  molecular and light detecting instrument 
A)  mass analysis by light-detected ions 
B)  matrix assisted laser desorption ionization 
C)  many atom loss-detecting ionization 
D)  molecular and light detecting instrument

Question 2

What is the most likely moleuclar 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 moleuclar formula...

Question 3

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

Accepted Answer

A)  electron injection 
B)  electron impact 
C)  energy initiated 
D)  energy insertion 
A)  electron injection 
B)  electron impact 
C)  energy initiated 
D)  energy insertion

Question 4

Which of the following is the definition of the base peak of a mass spectrum?

Accepted Answer

A)  the peak corresponding to the most abundant ion 
B)  the peak corresponding to the ion with lowest m/e 
C)  the peak corresponding to the molecular ion peak 
D)  the peak corresponding to the ion arising to loss of a proton from the molecular ion 
A)  the peak corresponding to the most abundant ion 
B)  the peak corresponding to the ion with lowest m/e 
C)  the peak corresponding to the molecular ion peak 
D)  the peak corresponding to the ion arising to loss of a proton from the molecular ion

Question 5

Which of the following sets of molecular ions does a dibromoalkane 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 6

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

Accepted Answer

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

Question 7

Which of the following alcohols does not give a prominent M - 15 ion?

Accepted Answer

A)  isopropyl alcohol 
B)  tert-butyl alcohol 
C)  2-hexanol 
D)  3-pentanol 
A)  isopropyl alcohol 
B)  tert-butyl alcohol 
C)  2-hexanol 
D)  3-pentanol

Question 8

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 9

Which of the following gives rise to a prominent peak in the mass spectrum with m/z of 43?

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 10

Which of the following sets of molecular ions does an alkyl bromide 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 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

Which of the following does not give rise to a prominent M - 41 peak in the mass spectrum?

Accepted Answer

A)  1-hexene 
B)  3-methyl-1-hexene 
C)  4-methyl-1-hexene 
D)  5-methyl-1-hexene 
A)  1-hexene 
B)  3-methyl-1-hexene 
C)  4-methyl-1-hexene 
D)  5-methyl-1-hexene

Question 13

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 14

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

Accepted Answer

A)  CH4-  x + 2 e- 
B)  CH3- + Hx 
C)  CH4+x + 2 e- 
D)  CH3x + H+ + 2 e- 
A)  CH4-  x + 2 e- 
B)  CH3- + Hx 
C)  CH4+x + 2 e- 
D)  CH3x + H+ + 2 e-

Question 15

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

Accepted Answer

A)  cyclopentane 
B)  cyclopentene 
C)  cyclopentanol 
D)  methylcyclopentane 
A)  cyclopentane 
B)  cyclopentene 
C)  cyclopentanol 
D)  methylcyclopentane

Question 16

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 17

What is the principle that allows us to use mass spectrometry to determine the molecular weight of a compound?

Accepted Answer

A)  higher molecular weight compounds are less volatile 
B)  higher molecular weight compounds are more dense 
C)  a beam of higher molecular weight cations is deflected less by a magnetic field 
D)  ions with higher molecular weight absorb higher frequencies of light 
A)  higher molecular weight compounds are less volatile 
B)  higher molecular weight compounds are more dense 
C)  a beam of higher molecular weight cations is deflected less by a magnetic field 
D)  ions with higher molecular weight absorb higher frequencies of light

Question 18

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

Accepted Answer

A)  cyclohexane 
B)  cyclohexene 
C)  1-chlorocyclohexane 
D)  cyclohexanol 
A)  cyclohexane 
B)  cyclohexene 
C)  1-chlorocyclohexane 
D)  cyclohexanol

Question 19

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

Exam 14: Mass Spectrometry

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

What is the most likely moleuclar 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.

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

Which of the following is the definition of the base peak of a mass spectrum?

Which of the following sets of molecular ions does a dibromoalkane possess?

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

Which of the following alcohols does not give a prominent M - 15 ion?

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 gives rise to a prominent peak in the mass spectrum with m/z of 43?

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

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?

Which of the following does not give rise to a prominent M - 41 peak in the mass spectrum?

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

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

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

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

What is the principle that allows us to use mass spectrometry to determine the molecular weight of a compound?

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

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

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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