Question 1

Hydrogen that are diastereotopic will show different chemical signals in the proton NMR.

Accepted Answer

A) True 
 B)False

Question 2

Consider the expected splitting of signal "b" in the 1H NMR spectrum of 1-methoxy-2-methylpropane,shown below.Presuming that Jab is sufficiently different from Jbc and that the instrument has sufficient resolving power,what is the theoretical multiplicity of signal "b"?

Accepted Answer

A) 8 
B) 9 
C) 12 
D) 21 
E) 24 
A) 8 
B) 9 
C) 12 
D) 21 
E) 24

Question 3

Predict the 1H NMR spectrum of diethoxymethane,CH3CH2OCH2OCH2CH3.

Accepted Answer

Question 4

For the following compound how many different signals would you see in the proton NMR? (Assume that you can see them all.)

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 5

For the following compound how many different signals would you see in the carbon NMR? (Assume that you can see them all.)

Accepted Answer

A) 4 
B) 5 
C) 6 
D) 7 
E) 8 
A) 4 
B) 5 
C) 6 
D) 7 
E) 8

Question 6

The 1H NMR spectrum of which of these compounds would consist of a triplet,singlet and quartet only?

Accepted Answer

A) 2-chloro-4-methylpentane 
B) 3-chloro-2-methylpentane 
C) 3-chloropentane 
D) 1-chloro-2,2-dimethylbutane 
E) 3-chloro-3-methylpentane 
A) 2-chloro-4-methylpentane 
B) 3-chloro-2-methylpentane 
C) 3-chloropentane 
D) 1-chloro-2,2-dimethylbutane 
E) 3-chloro-3-methylpentane

Question 7

For the following compound how many different signals would you see in the carbon NMR? (Assume that you can see them all.)

Accepted Answer

A) 3 
B) 4 
C) 5 
D) 6 
E) 7 
A) 3 
B) 4 
C) 5 
D) 6 
E) 7

Question 8

Briefly explain how you might distinguish between 1-butyne and 2-butyne by comparing their 1H-NMR spectra.

Accepted Answer

1-butyne will show 3

Question 9

Predict the splitting pattern you would observe for the proton at C4 of 2,3-dimethyl-2-phenylbutane.

Accepted Answer

A) Doublet 
B) Singlet 
C) Quartet 
D) Septet 
E) Octet 
A) Doublet 
B) Singlet 
C) Quartet 
D) Septet 
E) Octet

Question 10

Consider the expected splitting of the C2 proton signal in the 1H NMR spectrum of 1,1-dibromopentane.Presuming that the coupling constants for neighboring protons are sufficiently different,and that the instrument has sufficient resolving power,what is the theoretical multiplicity of the C2 proton signal?

Accepted Answer

A) 3 
B) 4 
C) 5 
D) 6 
E) 8 
A) 3 
B) 4 
C) 5 
D) 6 
E) 8

Question 11

For the following compound how many different signals would you see in the carbon NMR? (Assume that you can see them all.)

Accepted Answer

A) 4 
B) 5 
C) 6 
D) 7 
E) 8 
A) 4 
B) 5 
C) 6 
D) 7 
E) 8

Question 12

Examine the 1H NMR spectrum of 1-nitropropane,shown below.Assign the signals to the respective hydrogen atoms in the molecule.

Accepted Answer

Question 13

A prominent (M+$\bullet$-18)peak suggests that the compound might be a(n):

Accepted Answer

A) Alkane 
B) Alcohol 
C) Ether 
D) Ketone 
E) Primary amine 
A) Alkane 
B) Alcohol 
C) Ether 
D) Ketone 
E) Primary amine

Question 14

A compound C5H11Cl which exhibits only two singlets in the 1H NMR spectrum must be:

Accepted Answer

A) 1-Chloropentane 
B) 1-Chloro-2,2-dimethylpropane 
C) 1-Chloro-2-methylbutane 
D) 3-Chloropentane 
E) 1-Chloro-3-methylbutane 
A) 1-Chloropentane 
B) 1-Chloro-2,2-dimethylpropane 
C) 1-Chloro-2-methylbutane 
D) 3-Chloropentane 
E) 1-Chloro-3-methylbutane

Question 15

Which is the base peak?

Accepted Answer

A) 15 
B) 29 
C) 44 
D) 45 
E) 100 
A) 15 
B) 29 
C) 44 
D) 45 
E) 100

Question 16

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C10H11N? Looking at the 13C-NMR you notice 10 distinct peaks,and the IR has a characteristic peak around 2250 cm-1.Relative integration is shown.

Accepted Answer

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

Question 17

Which compound below would give rise to 5 signals in the proton NMR spectrum and 7 signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) None of these choices. 
A) I 
B) II 
C) III 
D) IV 
E) None of these choices.

Question 18

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C7H12O4? The 13C-NMR spectrum shows peaks at 14.1,40.8,61.0 and 166.8 ppm.Relative integration is shown.

Accepted Answer

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

Question 19

Which one of the following best represents the predicted approximate chemical shift and coupling for the hydrogen(s)indicated with the arrow?

Accepted Answer

A) 1.00 ppm,quartet 
B) 2.40 ppm,singlet 
C) 2.40 ppm,quartet 
D) 3.00 ppm,quartet 
E) 1.00 ppm,triplet 
A) 1.00 ppm,quartet 
B) 2.40 ppm,singlet 
C) 2.40 ppm,quartet 
D) 3.00 ppm,quartet 
E) 1.00 ppm,triplet

Question 20

Consider the expected splitting of signal "b" in the 1H NMR spectrum of 1,2-dimethoxypropane,shown below.Presuming that Jbc is sufficiently different from Jbd and that the instrument has sufficient resolving power,what is the theoretical multiplicity of signal "b"?

Accepted Answer

A) 2 
B) 5 
C) 6 
D) 8 
E) 12 
A) 2 
B) 5 
C) 6 
D) 8 
E) 12

Exam 9: Nuclear Magnetic Resonance and Mass Spectrometry

Hydrogen that are diastereotopic will show different chemical signals in the proton NMR.

Consider the expected splitting of signal "b" in the 1H NMR spectrum of 1-methoxy-2-methylpropane,shown below.Presuming that Jab is sufficiently different from Jbc and that the instrument has sufficient resolving power,what is the theoretical multiplicity of signal "b"?

Predict the 1H NMR spectrum of diethoxymethane,CH3CH2OCH2OCH2CH3.

For the following compound how many different signals would you see in the proton NMR? (Assume that you can see them all.)

For the following compound how many different signals would you see in the carbon NMR? (Assume that you can see them all.)

The 1H NMR spectrum of which of these compounds would consist of a triplet,singlet and quartet only?

For the following compound how many different signals would you see in the carbon NMR? (Assume that you can see them all.)

Briefly explain how you might distinguish between 1-butyne and 2-butyne by comparing their 1H-NMR spectra.

Predict the splitting pattern you would observe for the proton at C4 of 2,3-dimethyl-2-phenylbutane.

For the following compound how many different signals would you see in the carbon NMR? (Assume that you can see them all.)

Examine the 1H NMR spectrum of 1-nitropropane,shown below.Assign the signals to the respective hydrogen atoms in the molecule.

A prominent (M+ ∙\bullet∙ -18)peak suggests that the compound might be a(n):

A compound C5H11Cl which exhibits only two singlets in the 1H NMR spectrum must be:

Which is the base peak?

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C10H11N? Looking at the 13C-NMR you notice 10 distinct peaks,and the IR has a characteristic peak around 2250 cm-1.Relative integration is shown.

Which compound below would give rise to 5 signals in the proton NMR spectrum and 7 signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C7H12O4? The 13C-NMR spectrum shows peaks at 14.1,40.8,61.0 and 166.8 ppm.Relative integration is shown.

Which one of the following best represents the predicted approximate chemical shift and coupling for the hydrogen(s)indicated with the arrow?

Consider the expected splitting of signal "b" in the 1H NMR spectrum of 1,2-dimethoxypropane,shown below.Presuming that Jbc is sufficiently different from Jbd and that the instrument has sufficient resolving power,what is the theoretical multiplicity of signal "b"?

The Basics

Families of Carbon

Acids and Bases

Nomenclature and Conformations of Alkanes and Cycloalkanes

Stereochemistry

Nucleophilic Reactions

Alkenes and Alkynes I

Alkenes and Alkynes II

Radical Reactions

Alcohols and Ethers

Alcohols From Carbonyl Compounds

Conjugated Unsaturated Systems

Aromatic Compounds

Reactions of Aromatic Compounds

Aldehydes and Ketones

Carboxylic Acids and Their Derivatives

Reactions at the Α Carbon of Carbonyl Compounds

Condensation and Conjugate Addition Reactions of Carbonyl Compounds

Amines

Transition Metal Complexes

Carbohydrates

Lipids

Amino Acids and Proteins

Nucleic Acids and Protein Synthesis

Filters

Consider the expected splitting of signal "b" in the ¹H NMR spectrum of 1-methoxy-2-methylpropane,shown below.Presuming that J_ab is sufficiently different from J_bc and that the instrument has sufficient resolving power,what is the theoretical multiplicity of signal "b"?

Predict the ¹H NMR spectrum of diethoxymethane,CH₃CH₂OCH₂OCH₂CH₃.

The ¹H NMR spectrum of which of these compounds would consist of a triplet,singlet and quartet only?

Briefly explain how you might distinguish between 1-butyne and 2-butyne by comparing their ¹H-NMR spectra.

Examine the ¹H NMR spectrum of 1-nitropropane,shown below.Assign the signals to the respective hydrogen atoms in the molecule.

A prominent (M⁺ $\bullet$ -18)peak suggests that the compound might be a(n):

A compound C₅H₁₁Cl which exhibits only two singlets in the ¹H NMR spectrum must be:

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₁₀H₁₁N? Looking at the ¹³C-NMR you notice 10 distinct peaks,and the IR has a characteristic peak around 2250 cm^-1.Relative integration is shown.

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₇H₁₂O₄? The ¹³C-NMR spectrum shows peaks at 14.1,40.8,61.0 and 166.8 ppm.Relative integration is shown.

Consider the expected splitting of signal "b" in the ¹H NMR spectrum of 1,2-dimethoxypropane,shown below.Presuming that J_bc is sufficiently different from J_bd and that the instrument has sufficient resolving power,what is the theoretical multiplicity of signal "b"?