Question 1

High-resolution mass spectrometry is used to determine the _____ of a compound.

Accepted Answer

A) degree of unsaturation 
B) molecular formula 
C) molecular weight 
D) B & C 
E) none of these 
A) degree of unsaturation 
B) molecular formula 
C) molecular weight 
D) B & C 
E) none of these

Question 2

Which of the following is not true about the molecular ion in mass spectrometry?

Accepted Answer

A) The molecular ion is produced by loss of one electron from the molecule. 
B) The mass of the molecular ion is equivalent to the mass of the molecule. 
C) The ion is produced by a loss of pair of electrons from the molecule. 
D) The molecular ion is often unstable and can undergo fragmentation. 
E) none of these 
A) The molecular ion is produced by loss of one electron from the molecule. 
B) The mass of the molecular ion is equivalent to the mass of the molecule. 
C) The ion is produced by a loss of pair of electrons from the molecule. 
D) The molecular ion is often unstable and can undergo fragmentation. 
E) none of these

Question 3

Which of the following is not true about electromagnetic radiation?

Accepted Answer

A) frequency is directly proportional to wavelength 
B) frequency is directly proportional to energy 
C) frequency is inversely proportional to wavelength 
D) wavelength is inversely proportional to energy 
E) none of these 
A) frequency is directly proportional to wavelength 
B) frequency is directly proportional to energy 
C) frequency is inversely proportional to wavelength 
D) wavelength is inversely proportional to energy 
E) none of these

Question 4

Which of the following is expected to be the base peak in the mass spectrum of pentanal?

Accepted Answer

A) 29 
B) 41 
C) 44 
D) 58 
E) 86 
A) 29 
B) 41 
C) 44 
D) 58 
E) 86

Question 5

Which of the following compounds have the same degree of unsaturation?

Accepted Answer

A) I & II 
B) I & III 
C) III & IV 
D) II & III 
E) none of these 
A) I & II 
B) I & III 
C) III & IV 
D) II & III 
E) none of these

Question 6

GC-mass spectrometry is used to find the _________ of each compound in a __________.

Accepted Answer

A) molecular formula,mixture of alkanes 
B) molecular weight,mixture of compounds 
C) molecular formula,mixture of compounds 
D) B & C 
E) none of these 
A) molecular formula,mixture of alkanes 
B) molecular weight,mixture of compounds 
C) molecular formula,mixture of compounds 
D) B & C 
E) none of these

Question 7

The separation of ions in the mass spectrometer is done by their ______.

Accepted Answer

A) electrons to protons ratio 
B) mass to neutrons ratio 
C) protons to neutrons ratio 
D) mass to charge ratio 
E) none of these 
A) electrons to protons ratio 
B) mass to neutrons ratio 
C) protons to neutrons ratio 
D) mass to charge ratio 
E) none of these

Question 8

Electrospray ionization is used to obtain mass spectra of proteins because:

Accepted Answer

A) it allows for faster fragmentation of molecular ion 
B) the molecular ion usually does not undergo fragmentation 
C) it allows for slow fragmentation of molecular ion 
D) none of these 
A) it allows for faster fragmentation of molecular ion 
B) the molecular ion usually does not undergo fragmentation 
C) it allows for slow fragmentation of molecular ion 
D) none of these

Question 9

Primary amines show two medium absorption bands around 3400 cm-1,due to _______.

Accepted Answer

A) symmetric stretching 
B) asymmetric stretching 
C) both symmetric and asymmetric stretching 
D) hydrogen bonding 
A) symmetric stretching 
B) asymmetric stretching 
C) both symmetric and asymmetric stretching 
D) hydrogen bonding

Question 10

Which of the following compounds will have a prominent peak at (M-127)?

Accepted Answer

A) CH3CH2CH2I 
B) (CH3CH2)3CCH2Cl 
C) (CH3)3CCH2CH2Br 
D) (CH3)2CHCH(CH3)2 
E) none of these 
A) CH3CH2CH2I 
B) (CH3CH2)3CCH2Cl 
C) (CH3)3CCH2CH2Br 
D) (CH3)2CHCH(CH3)2 
E) none of these

Question 11

Which of the following corresponds to the fingerprint region on an IR spectrum?

Accepted Answer

A) 1500-4000cm-1 
B) 400-4000cm-1 
C) 400-1500cm-1 
D) 1500-2500cm-1 
E) none of these 
A) 1500-4000cm-1 
B) 400-4000cm-1 
C) 400-1500cm-1 
D) 1500-2500cm-1 
E) none of these

Question 12

Provide a molecular formula that is consistent with the following mass spectrum data.M+ .  at m/z= 73,relative height=86.1%
(M+1)+ .  at m/z= 74,relative height=3.2%

Accepted Answer

C<sub>3</s

Question 13

Which molecular formula is consistent with the following mass spectrum data? M+ .  at m/z= 78,relative height=23.5%
(M+1)+ .  at m/z= 79,relative height=0.78%
(M+2)+ .  at m/z= 80,relative height=7.5%

Accepted Answer

A) C6H6 
B) C3H7Cl 
C) C6H8 
D) C6H9Cl 
E) none of these 
A) C6H6 
B) C3H7Cl 
C) C6H8 
D) C6H9Cl 
E) none of these

Question 14

Which one of the following compounds is consistent with the mass spectrum below?   SDBS: National Institute of Advanced Industrial Science and Technology

Accepted Answer

A) CH3CH2CH(CH3)2 
B) CH3CHOHCH2CH3 
C) CH3CH2OCH2CH3 
D) CH3CH2NHCH2CH3 
E) none of these 
A) CH3CH2CH(CH3)2 
B) CH3CHOHCH2CH3 
C) CH3CH2OCH2CH3 
D) CH3CH2NHCH2CH3 
E) none of these

Question 15

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

Accepted Answer

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

Question 16

A compound with molecular formula C4H8O2,shows absorptions at 2200-3600 cm-1 (broad),1720 cm-1 and at 1200 cm-1 on the IR spectrum.Propose a possible structure for this compound.

Accepted Answer

Question 17

For the following reaction,which of the following is consistent with the IR spectrum of the product?

Accepted Answer

A) absorption at 2250 cm-1 should disappear 
B) absorption at 3200-3400 cm-1 and 1720cm-1 should appear 
C) absorption at 2250 cm-1 should disappear,new absorption at 2600-2800 cm-1 and 1720 cm-1 should appear. 
D) absorption at 2250 cm-1 should disappear and absorption around 3400 cm-1 should appear. 
E) none of these 
A) absorption at 2250 cm-1 should disappear 
B) absorption at 3200-3400 cm-1 and 1720cm-1 should appear 
C) absorption at 2250 cm-1 should disappear,new absorption at 2600-2800 cm-1 and 1720 cm-1 should appear. 
D) absorption at 2250 cm-1 should disappear and absorption around 3400 cm-1 should appear. 
E) none of these

Question 18

Compounds containing chlorine or bromine usually show a strong _____peak.

Accepted Answer

A) molecular ion 
B) base 
C) M+1 
D) M+2 
E) all of these 
A) molecular ion 
B) base 
C) M+1 
D) M+2 
E) all of these

Question 19

Provide the structure of the major fragment that results when the molecular ion of
CH3CH2CH2CH2OH undergoes fragmentation via alpha cleavage.

Accepted Answer

Question 20

For the following reaction,which of the following is consistent with the IR spectrum of the product?

Accepted Answer

A) absorption at 2150 cm-1 should disappear 
B) absorption at 3300 cm-1 and 2150cm-1 should disappear 
C) absorption at 2250 cm-1 should disappear,new absorption at 3300 cm-1 should appear 
D) absorption at 1650 cm-1 should disappear and absorption at 3300 cm-1 should appear 
E) absorption at 3300 cm-1 and 2150cm-1 should disappear,a new absorption at 1720 cm-1 should appear 
A) absorption at 2150 cm-1 should disappear 
B) absorption at 3300 cm-1 and 2150cm-1 should disappear 
C) absorption at 2250 cm-1 should disappear,new absorption at 3300 cm-1 should appear 
D) absorption at 1650 cm-1 should disappear and absorption at 3300 cm-1 should appear 
E) absorption at 3300 cm-1 and 2150cm-1 should disappear,a new absorption at 1720 cm-1 should appear

Exam 15: Infrared Spectroscopy and Mass Spectrometry

High-resolution mass spectrometry is used to determine the _____ of a compound.

Which of the following is not true about the molecular ion in mass spectrometry?

Which of the following is not true about electromagnetic radiation?

Which of the following is expected to be the base peak in the mass spectrum of pentanal?

Which of the following compounds have the same degree of unsaturation?

GC-mass spectrometry is used to find the _________ of each compound in a __________.

The separation of ions in the mass spectrometer is done by their ______.

Electrospray ionization is used to obtain mass spectra of proteins because:

Primary amines show two medium absorption bands around 3400 cm-1,due to _______.

Which of the following compounds will have a prominent peak at (M-127)?

Which of the following corresponds to the fingerprint region on an IR spectrum?

Provide a molecular formula that is consistent with the following mass spectrum data.M+ . at m/z= 73,relative height=86.1% (M+1)+ . at m/z= 74,relative height=3.2%

Which molecular formula is consistent with the following mass spectrum data? M+ . at m/z= 78,relative height=23.5% (M+1)+ . at m/z= 79,relative height=0.78% (M+2)+ . at m/z= 80,relative height=7.5%

Which one of the following compounds is consistent with the mass spectrum below? SDBS: National Institute of Advanced Industrial Science and Technology

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

A compound with molecular formula C4H8O2,shows absorptions at 2200-3600 cm-1 (broad),1720 cm-1 and at 1200 cm-1 on the IR spectrum.Propose a possible structure for this compound.

For the following reaction,which of the following is consistent with the IR spectrum of the product?

Compounds containing chlorine or bromine usually show a strong _____peak.

Provide the structure of the major fragment that results when the molecular ion of CH3CH2CH2CH2OH undergoes fragmentation via alpha cleavage.

For the following reaction,which of the following is consistent with the IR spectrum of the product?

A Review of General Chemistry: Electrons, Bonds, and Molecular Properties

Molecular Representations

Acids and Bases

Alkanes and Cycloalkanes

Stereoisomerism

Chemical Reactivity and Mechanisms

Substitution Reactions

Alkenes: Structure and Preparation Via 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

Carbohydrates

Amino Acids, Peptides, and Proteins

Lipids

Synthetic Polymers

Filters

GC-mass spectrometry is used to find the _ of each compound in a __.

Primary amines show two medium absorption bands around 3400 cm^-1,due to _______.

Provide a molecular formula that is consistent with the following mass spectrum data.M⁺ ^. at m/z= 73,relative height=86.1% (M+1)⁺ ^. at m/z= 74,relative height=3.2%

Which molecular formula is consistent with the following mass spectrum data? M⁺ ^. at m/z= 78,relative height=23.5% (M+1)⁺ ^. at m/z= 79,relative height=0.78% (M+2)⁺ ^. at m/z= 80,relative height=7.5%

A compound with molecular formula C₄H₈O₂,shows absorptions at 2200-3600 cm^-1 (broad),1720 cm^-1 and at 1200 cm^-1 on the IR spectrum.Propose a possible structure for this compound.

Provide the structure of the major fragment that results when the molecular ion of CH₃CH₂CH₂CH₂OH undergoes fragmentation via alpha cleavage.