Question 1

Which of the following wavenumber corresponds to the functional group 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 2

Which of the following information is primarily obtained from infrared spectroscopy?

Accepted Answer

A)  arrangement of carbon and hydrogen atoms in a compound 
B)  molecular weight of a compound 
C)  conjugated  $\pi$ system present in a compound 
D)  functional groups present in a compound 
E)  all of these 
A)  arrangement of carbon and hydrogen atoms in a compound 
B)  molecular weight of a compound 
C)  conjugated  $\pi$ system present in a compound 
D)  functional groups present in a compound 
E)  all of these

Question 3

Which of the following m/z values corresponds to the base peak for 2-chloro-2-methylpropane?

Accepted Answer

A)  15 
B)  92 
C)  77 
D)  47 
E)  57 
A)  15 
B)  92 
C)  77 
D)  47 
E)  57

Question 4

Arrange the following electromagnetic radiation in decreasing (highest to lowest) order of frequency.

Accepted Answer

A)  V>III>IV>II>I 
B)  II>V>III>IV>I 
C)  I>IV>III>V>II 
D)  V>II>IV>III>I 
E)  II>IV>V>III>I 
A)  V>III>IV>II>I 
B)  II>V>III>IV>I 
C)  I>IV>III>V>II 
D)  V>II>IV>III>I 
E)  II>IV>V>III>I

Question 5

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

Accepted Answer

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

Question 6

Rank absorption of the indicated bonds in decreasing (highest to lowest) order of wavenumber.

Accepted Answer

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

Question 7

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 8

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

Accepted Answer

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

Question 9

How will you distinguish between the following compounds using high-resolution mass spectrometry?

Accepted Answer

Compound I: m/z at 9

Question 10

Which molecular formula is consistent with the following mass spectrum data? M+ .  at m/z= 72, relative height=73.0%
(M+1)+ .  at m/z= 73, relative height=3.3%

Accepted Answer

A)  C4H10O 
B)  C4H9N 
C)  C5H12 
D)  C4H8O  
E)  none of these 
A)  C4H10O 
B)  C4H9N 
C)  C5H12 
D)  C4H8O  
E)  none of these

Question 11

In mass spectrometry using electron impact ionization technique, a beam of high-energy electrons initially ejects one electron from the compound being studied. This produces a positively charged ion called the ____________________.

Accepted Answer

The answer of In mass spectrometry using electron impact ionization...

Question 12

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 13

Which of the following compounds will have a base peak at m/z=43?

Accepted Answer

A)  CH3CH2CH2CH2CH2CH3 
B)  (CH3CH2)2CHCH3 
C)  (CH3)3CCH2CH3 
D)  (CH3)2CHCH(CH3)2 
E)  none of these 
A)  CH3CH2CH2CH2CH2CH3 
B)  (CH3CH2)2CHCH3 
C)  (CH3)3CCH2CH3 
D)  (CH3)2CHCH(CH3)2 
E)  none of these

Question 14

Predict the product for the following reaction and explain how you will use IR spectroscopy to monitor the progress of the reaction.

Accepted Answer

@#IMG-DLM& Absorptions for C=O around 17

Question 15

Which of the following alkene groups will produce the stronger signal? Explain why.

Accepted Answer

Compound II.
The C=C in compou

Question 16

For which of the following compounds will the (M+2)+ .  peak intensity be equal to the intensity of the molecular ion peak?

Accepted Answer

A)  CH3CH2CH2Br 
B)  CH3CH2CH2OH 
C)  CH3CH2CH2Cl 
D)  CH3CH2CH2NH2 
E)  none of these 
A)  CH3CH2CH2Br 
B)  CH3CH2CH2OH 
C)  CH3CH2CH2Cl 
D)  CH3CH2CH2NH2 
E)  none of these

Question 17

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 18

For the following pair of compounds the expected stretching absorption of the C=O bond is 1685cm-1 & 1655cm-1 respectively. Explain using both words and structural drawings.

Accepted Answer

Both compounds I and II have conjugated

Question 19

Which of the following is always true about the base peak in a mass spectrum?

Accepted Answer

A)  peak corresponding to molecular ion 
B)  peak corresponding to the most abundant ion 
C)  peak corresponding to lowest m/z 
D)  A & C 
E)  none of these 
A)  peak corresponding to molecular ion 
B)  peak corresponding to the most abundant ion 
C)  peak corresponding to lowest m/z 
D)  A & C 
E)  none of these

Question 20

Rank absorption of the indicated bonds in decreasing (highest to lowest) order of wavenumber.

Accepted Answer

A)  I>V>II>IV>III 
B)  IV>II>I>V>III 
C)  II>I>V>III>IV 
D)  IV>I>V>II>III 
E)  IV>II>V>I>III 
A)  I>V>II>IV>III 
B)  IV>II>I>V>III 
C)  II>I>V>III>IV 
D)  IV>I>V>II>III 
E)  IV>II>V>I>III

Exam 15: Infrared Spectroscopy and Mass Spectrometry

Which of the following wavenumber corresponds to the functional group region on an IR spectrum?

Which of the following information is primarily obtained from infrared spectroscopy?

Which of the following m/z values corresponds to the base peak for 2-chloro-2-methylpropane?

Arrange the following electromagnetic radiation in decreasing (highest to lowest) order of frequency.

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

Rank absorption of the indicated bonds in decreasing (highest to lowest) order of wavenumber.

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 following IR spectrum? SDBS: National Institute of Advanced Industrial Science and Technology

How will you distinguish between the following compounds using high-resolution mass spectrometry?

Which molecular formula is consistent with the following mass spectrum data? M+ . at m/z= 72, relative height=73.0% (M+1)+ . at m/z= 73, relative height=3.3%

In mass spectrometry using electron impact ionization technique, a beam of high-energy electrons initially ejects one electron from the compound being studied. This produces a positively charged ion called the ____________________.

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

Which of the following compounds will have a base peak at m/z=43?

Predict the product for the following reaction and explain how you will use IR spectroscopy to monitor the progress of the reaction.

Which of the following alkene groups will produce the stronger signal? Explain why.

For which of the following compounds will the (M+2)+ . peak intensity be equal to the intensity of the molecular ion peak?

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 pair of compounds the expected stretching absorption of the C=O bond is 1685cm-1 & 1655cm-1 respectively. Explain using both words and structural drawings.

Which of the following is always true about the base peak in a mass spectrum?

Rank absorption of the indicated bonds in decreasing (highest to lowest) order of wavenumber.

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

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 molecular formula is consistent with the following mass spectrum data? M⁺ ^. at m/z= 72, relative height=73.0% (M+1)⁺ ^. at m/z= 73, relative height=3.3%

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

For which of the following compounds will the (M+2)⁺ ^. peak intensity be equal to the intensity of the molecular ion peak?

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 pair of compounds the expected stretching absorption of the C=O bond is 1685cm^-1& 1655cm^-1 respectively. Explain using both words and structural drawings.