Question 1

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

Accepted Answer

A)   i
B)   ii
C)   iii
D)   ivE) None of the above
F) A) and C) A

Question 2

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 acidE) B) and C)
F) A) and D)

Question 3

What is the x-axis of a mass spectrum?

Accepted Answer

A)   mass
B)   mass/energy
C)   mass/charge
D)   chargeE) B) and C)
F) C) and D)

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 acidE) B) and C)
F) A) and D)

Question 5

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 - 12E) None of the above
F) All of the above

Question 6

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-methylpentaneE) C) and D)
F) A) and D)

Question 7

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 cationsE) None of the above
F) A) and B)

Question 8

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-methylpentaneE) All of the above
F) None of the above

Question 9

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 moleculeE) A) and C)
F) All of the above C

Question 10

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...

Question 11

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 unitsE) None of the above
F) A) and B)

Question 12

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 - 29E) C) and D)
F) None of the above

Question 13

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 bashingE) None of the above
F) All of the above

Question 14

What is the y-axis of a mass spectrum?

Accepted Answer

A)   mass
B)   energy
C)   abundance
D)   field strengthE) A) and D)
F) None of the above

Question 15

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-chlorohexaneE) None of the above
F) A) and B)

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)   12E) A) and D)
F) A) and C)

Question 17

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 hydrocarbonE) All of the above
F) C) and D)

Question 18

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)   ethylbenzeneE) B) and D)
F) A) and D) D

Question 19

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)   C8H14Br2E) B) and C)
F) None of the above

Question 20

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...

Exam 14: Mass Spectrometry

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

Correct AnswerverifiedA

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

Correct AnswerverifiedShow Answer

What is the x-axis of a mass spectrum?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedC

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

What is the y-axis of a mass spectrum?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedD

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

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

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A

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C

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D

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