Question 1

What structure of formula C3H6Br2 would give the following proton NMR spectrum?

Accepted Answer

A) 
    
B) 
  
C) 
  
D) 
  
E)  None of the above. 
A) 
    
B) 
  
C) 
  
D) 
  
E)  None of the above. B

Question 2

In the proton-coupled 13C-NMR spectrum of the following molecule,how many doublets would be observed?

Accepted Answer

A)  2 
B)  4 
C)  6 
D)  8 
E)  None of the above. 
A)  2 
B)  4 
C)  6 
D)  8 
E)  None of the above. C

Question 3

The natural abundance of 13C is

Accepted Answer

A)  2.1%. 
B)  10%. 
C)  1.5%. 
D)  1.1%. 
E)  16%. 
A)  2.1%. 
B)  10%. 
C)  1.5%. 
D)  1.1%. 
E)  16%. D

Question 4

How many different types of carbon would be present in the following molecule?

Accepted Answer

A)  three 
B)  four 
C)  five 
D)  six 
E)  eight 
A)  three 
B)  four 
C)  five 
D)  six 
E)  eight

Question 5

The proton NMR spectrum of a carboxylic acid,C13H18O2,commonly sold as an over-the-counter headache remedy,is shown below.Note: the CO2H proton is not shown,and the multiplicity of the peaks are noted (d = doublet,q = quartet,m = multiplet).Which structure is that of this pharmaceutical?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Question 6

Which of the following structures will give three signals (not counting TMS)in the proton decoupled 13C NMR?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Question 7

The following 1H-NMR was most likely obtained from which of the compounds listed below?

Accepted Answer

A) 
    
B) 
  
C) 
  
D) 
  
E) 
  
A) 
    
B) 
  
C) 
  
D) 
  
E)

Question 8

The NMR peak intensities for a first-order quartet are:

Accepted Answer

A)  1:2:2:1 
B)  1:3:3:1 
C)  1:4:4:1 
D)  1:1:1:1 
E)  None of the above. 
A)  1:2:2:1 
B)  1:3:3:1 
C)  1:4:4:1 
D)  1:1:1:1 
E)  None of the above.

Question 9

Acetone would show how many doublets in the proton-coupled 13C NMR spectrum?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  4 
A)  0 
B)  1 
C)  2 
D)  3 
E)  4

Question 10

For the compound below give the spin-spin splitting that would be observed for each of the protons sets in the 1H NMR spectrum.

Accepted Answer

A)  Ha = triplet Hb = doublet,Hc = quartet 
B)  Ha = singlet Hb = quartet,Hc = triplet 
C)  Ha = singlet Hb = pentet,Hc = quartet 
D)  Ha = triplet Hb = quartet,Hc = singlet 
E)  None of the above. 
A)  Ha = triplet Hb = doublet,Hc = quartet 
B)  Ha = singlet Hb = quartet,Hc = triplet 
C)  Ha = singlet Hb = pentet,Hc = quartet 
D)  Ha = triplet Hb = quartet,Hc = singlet 
E)  None of the above.

Question 11

For the compound below give the integration ratio that would be observed for each of the protons sets in the 1H NMR spectrum.

Accepted Answer

A)  Ha = 3,Hb = 2,Hc = 1 
B)  Ha = 1 Hb = 2,Hc = 1 
C)  Ha = 3 Hb = 2,Hc = 3 
D)  Ha = 1 Hb = 1,Hc = 1 
E)  None of the above. 
A)  Ha = 3,Hb = 2,Hc = 1 
B)  Ha = 1 Hb = 2,Hc = 1 
C)  Ha = 3 Hb = 2,Hc = 3 
D)  Ha = 1 Hb = 1,Hc = 1 
E)  None of the above.

Question 12

Which of the following is not true of 13C NMR?

Accepted Answer

A)  The sensitivity of 13C NMR is much less than that of proton NMR. 
B)  By simultaneously decoupling the proton region,13C peaks appear as singlets. 
C)  (13C chemical shifts cover a much larger range than do 1H chemical shifts.) 
D)  The 13C NMR spectrum can show more peaks than there are carbons in the molecular formula. 
E)  The 13C NMR spectrum will show one peak for each type of carbon in a molecule. 
A)  The sensitivity of 13C NMR is much less than that of proton NMR. 
B)  By simultaneously decoupling the proton region,13C peaks appear as singlets. 
C)  (13C chemical shifts cover a much larger range than do 1H chemical shifts.) 
D)  The 13C NMR spectrum can show more peaks than there are carbons in the molecular formula. 
E)  The 13C NMR spectrum will show one peak for each type of carbon in a molecule.

Question 13

A seven-carbon compound which gives three signals in the 13C NMR spectrum could be:

Accepted Answer

A)  heptane 
B)  2-methylhexane 
C)  3,3-dimethylpentane 
D)  2,4-dimethylpentane 
E)  2,2,3-trimethylbutane 
A)  heptane 
B)  2-methylhexane 
C)  3,3-dimethylpentane 
D)  2,4-dimethylpentane 
E)  2,2,3-trimethylbutane

Question 14

Indicate how 1H NMR spectroscopy can be used to distinguish between the following sets of structures.

Accepted Answer

A)  The spin-spin splitting for the protons on the carbon next to the halogen will be different. 
B)  The chemical shift of the resonance for the protons on the carbon attached to the chlorine atom will be shifted downfield relative to the protons on the carbon attached to the bromine atom. 
C)  The chemical shift of the resonance for the protons on the carbon attached to the chlorine atom will be shifted upfield relative to the protons on the carbon attached to the bromine atom. 
D)  The integration of the protons on the carbon next to the halogen will be different. 
E)  None of the above. 
A)  The spin-spin splitting for the protons on the carbon next to the halogen will be different. 
B)  The chemical shift of the resonance for the protons on the carbon attached to the chlorine atom will be shifted downfield relative to the protons on the carbon attached to the bromine atom. 
C)  The chemical shift of the resonance for the protons on the carbon attached to the chlorine atom will be shifted upfield relative to the protons on the carbon attached to the bromine atom. 
D)  The integration of the protons on the carbon next to the halogen will be different. 
E)  None of the above.

Question 15

The molecular formulas and 13C NMR data (in ppm)are given below.The splitting pattern of each signal,taken from the non-decoupled spectrum is given in parentheses.Deduce the correct structure:

Accepted Answer

A) 
    
B) 
  
C) 
  
D) 
  
E) 
  
A) 
    
B) 
  
C) 
  
D) 
  
E)

Question 16

In nuclear magnetic resonance,stronger magnetic fields

Accepted Answer

A)  give a higher sensitivity spectrum than do lower magnetic fields. 
B)  give different chemical shifts (in ppm)than would weaker magnets. 
C)  give better separation between peaks in the spectrum (in Hz)than would weaker magnets. 
D)  give different coupling constants than would be observed with weaker magnetic fields. 
E)  Both A and C are true. 
A)  give a higher sensitivity spectrum than do lower magnetic fields. 
B)  give different chemical shifts (in ppm)than would weaker magnets. 
C)  give better separation between peaks in the spectrum (in Hz)than would weaker magnets. 
D)  give different coupling constants than would be observed with weaker magnetic fields. 
E)  Both A and C are true.

Question 17

The following 1H-NMR spectrum was most likely obtained from which of the compounds listed below?

Accepted Answer

A) 
    
B) 
  
C) 
  
D) 
  
E) 
  
A) 
    
B) 
  
C) 
  
D) 
  
E)

Question 18

Which of the following structures C5H12O would give the NMR spectrum shown?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
E) 
  
A) 
  
B) 
  
C) 
  
D) 
  
E)

Question 19

How many different types of hydrogens are present in the following molecule?

Accepted Answer

A)  three 
B)  four 
C)  five 
D)  six 
E)  seven 
A)  three 
B)  four 
C)  five 
D)  six 
E)  seven

Question 20

Consider the 1H-NMR of the molecule shown below.Assume that JCB = 7 Hz and JCA = 1 Hz.What coupling pattern will Hc exhibit?

Accepted Answer

A)  pentet 
B)  quartet 
C)  doublet of quartets 
D)  triplet of triplets 
E)  doublet of triplets 
A)  pentet 
B)  quartet 
C)  doublet of quartets 
D)  triplet of triplets 
E)  doublet of triplets

Exam 10: Using Nuclear Magnetic Resonance Spectroscopy to Deduce Structure

What structure of formula C3H6Br2 would give the following proton NMR spectrum?

In the proton-coupled 13C-NMR spectrum of the following molecule,how many doublets would be observed?

The natural abundance of 13C is

How many different types of carbon would be present in the following molecule?

The proton NMR spectrum of a carboxylic acid,C13H18O2,commonly sold as an over-the-counter headache remedy,is shown below.Note: the CO2H proton is not shown,and the multiplicity of the peaks are noted (d = doublet,q = quartet,m = multiplet).Which structure is that of this pharmaceutical?

Which of the following structures will give three signals (not counting TMS)in the proton decoupled 13C NMR?

The following 1H-NMR was most likely obtained from which of the compounds listed below?

The NMR peak intensities for a first-order quartet are:

Acetone would show how many doublets in the proton-coupled 13C NMR spectrum?

For the compound below give the spin-spin splitting that would be observed for each of the protons sets in the 1H NMR spectrum.

For the compound below give the integration ratio that would be observed for each of the protons sets in the 1H NMR spectrum.

Which of the following is not true of 13C NMR?

A seven-carbon compound which gives three signals in the 13C NMR spectrum could be:

Indicate how 1H NMR spectroscopy can be used to distinguish between the following sets of structures.

The molecular formulas and 13C NMR data (in ppm)are given below.The splitting pattern of each signal,taken from the non-decoupled spectrum is given in parentheses.Deduce the correct structure:

In nuclear magnetic resonance,stronger magnetic fields

The following 1H-NMR spectrum was most likely obtained from which of the compounds listed below?

Which of the following structures C5H12O would give the NMR spectrum shown?

How many different types of hydrogens are present in the following molecule?

Consider the 1H-NMR of the molecule shown below.Assume that JCB = 7 Hz and JCA = 1 Hz.What coupling pattern will Hc exhibit?

Structure and Bonding in Organic Molecules

Structure and Reactivity: Acids and Bases,polar and Nonpolar Molecules

Reactions of Alkanes: Bond-Dissociation Energies,radical Halogenation,and Relative Reactivity

Cycloalkanes

Stereoisomers

Properties and Reactions of Haloalkanes: Bimolecular Nucleophilic Substitution

Further Reactions of Haloalkanes: Unimolecular Substitution and Pathways of Elimination

Hydroxy of Functional Group: Alcohols: Properties,preparation,and Strategy of Synthesis

Further Reactions of Alcohols and the Chemistry of Ethers

Alkenes: Infrared Spectroscopy and Mass Spectrometry

Reactions to Alkenes

Alkynes: the Carbon

Delocalized Pi Systems: Investigation by Ultraviolet and Visible Spectroscopy Interlude

Benzene and Aromaticity: Electrophilic Aromatic Substitution

Electrophilic Attack on Derivatives of Benzene: Substituents Control Regioselectivity

Aldehydes and Ketones: the Carbonyl Group

Enols,enolates,and the Aldol Condensation: A,b-Unsaturated Aldehydes and Ketones

Carboxylic Acids

Carboxylic Acid Derivatives

Amines and Their Derivatives: Functional Groups Containing Nitrogen

Chemistry of the Benzene Substituents: Alkylbenzenes,phenols,and Benzenamines

Ester Enolates and the Claisen Condensation: Synthesis of B-Dicarbonyl Compounds; Acyl Anion Equivalents

Carbohydrates: Polyfunctional Compounds in Nature

Heterocycles: Heteroatoms in Cyclic Organic Compounds

Amino Acids,peptides,proteins,and Nucleic Acids: Nitrogen-Containing Polymers in Nature

Filters

What structure of formula C₃H₆Br₂ would give the following proton NMR spectrum?

In the proton-coupled ¹³C-NMR spectrum of the following molecule,how many doublets would be observed?

The natural abundance of ¹³C is

Which of the following structures will give three signals (not counting TMS)in the proton decoupled ¹³C NMR?

The following ¹H-NMR was most likely obtained from which of the compounds listed below?

Acetone would show how many doublets in the proton-coupled ¹³C NMR spectrum?

For the compound below give the spin-spin splitting that would be observed for each of the protons sets in the ¹H NMR spectrum.

For the compound below give the integration ratio that would be observed for each of the protons sets in the ¹H NMR spectrum.

Which of the following is not true of ¹³C NMR?

A seven-carbon compound which gives three signals in the ¹³C NMR spectrum could be:

Indicate how ¹H NMR spectroscopy can be used to distinguish between the following sets of structures.

The molecular formulas and ¹³C NMR data (in ppm)are given below.The splitting pattern of each signal,taken from the non-decoupled spectrum is given in parentheses.Deduce the correct structure:

The following ¹H-NMR spectrum was most likely obtained from which of the compounds listed below?

Which of the following structures C₅H₁₂O would give the NMR spectrum shown?

Consider the ¹H-NMR of the molecule shown below.Assume that J_CB= 7 Hz and J_CA = 1 Hz.What coupling pattern will H_c exhibit?