Question 1

How many signals would you expect to find in the 1H NMR spectrum of CH3OCH2CH2OCH3?

Accepted Answer

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

Question 2

A compound C5H10O gave the following spectral data: 1H NMR spectrum IR spectrum
Doublet,$\delta$ 1.10 strong peak
Singlet,$\delta$ 2.10 near 1720 cm-1
Septet,$\delta$ 2.50
Which is a reasonable structure for the compound?

Accepted Answer

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

Question 3

Briefly explain how you might distinguish between the following substances by comparing their 1H-NMR spectra:

Accepted Answer

The main difference would likely be in t

Question 4

Briefly explain how you might distinguish between the following substances by comparing their 1H-NMR spectra:

Accepted Answer

The main difference would likely be in t

Question 5

An unknown compound,U,has the formula C6H4Cl2O.Elucidate the structure of U by scrutinizing its IR,1H NMR and 13C NMR spectra,shown below.

Accepted Answer

Question 6

The data below from the molecular ion region of the mass spectrum of a halogen-containing compound are consistent with the presence of what halogen(s)in the original compound? intensity
M+$\bullet$51.0
M+$\bullet$ +2 100.0
M+$\bullet$ +4 49.0

Accepted Answer

A) One Br 
B) One Cl 
C) One Br and one Cl 
D) Two Br 
E) Two Cl 
A) One Br 
B) One Cl 
C) One Br and one Cl 
D) Two Br 
E) Two Cl

Question 7

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C4H7Br? Relative integration is shown.

Accepted Answer

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

Question 8

For the compound adamantine,how many different signals would you see in the 13C NMR? (Assume that you can see them all.)

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) None of these choices. 
A) 1 
B) 2 
C) 3 
D) 4 
E) None of these choices.

Question 9

In the structure shown,Ha and Hb are classified as:

Accepted Answer

A) homotopic protons. 
B) vicinal protons. 
C) enantiotopic protons. 
D) diastereotopic protons. 
E) isomeric protons. 
A) homotopic protons. 
B) vicinal protons. 
C) enantiotopic protons. 
D) diastereotopic protons. 
E) isomeric protons.

Question 10

Consider the expected 1H NMR spectrum of 1,1,3,3-tetramethylcyclopentane.Which of the following is likely to be observed?

Accepted Answer

A) 7 signals: all singlets 
B) 7 signals: 4 singlets,3 doublets 
C) 3 signals: all singlets 
D) 3 signals: one singlet,2 doublets 
E) 3 signals: two singlets,one doublet 
A) 7 signals: all singlets 
B) 7 signals: 4 singlets,3 doublets 
C) 3 signals: all singlets 
D) 3 signals: one singlet,2 doublets 
E) 3 signals: two singlets,one doublet

Question 11

A compound with the molecular formula C8H9BrO gave the following 1H NMR spectrum: triplet,$\delta$ 1.4
Quartet,$\delta$ 3.9
Multiplet,$\delta$ 7.0 (4H)
There was no evidence of an -OH band in the IR spectrum.A possible structure for the compound is:

Accepted Answer

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

Question 12

How many chemically distinct 1H NMR signals are there in the following compound?

Accepted Answer

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

Question 13

Predict the 1H NMR spectrum of cis-1,4-cyclohexanediol if we perform the experiment in CD3OD.

Accepted Answer

Question 14

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) 1.10 ppm,singlet 
B) 2.10 ppm,doublet 
C) 3.40 ppm,singlet 
D) 4.5 ppm,singlet 
E) 3.5 ppm,quartet 
A) 1.10 ppm,singlet 
B) 2.10 ppm,doublet 
C) 3.40 ppm,singlet 
D) 4.5 ppm,singlet 
E) 3.5 ppm,quartet

Question 15

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) 1.10 ppm,singlet 
B) 2.10 ppm,triplet 
C) 3.40 ppm,triplet 
D) 4.5 ppm,singlet 
E) 5.3 ppm,doublet 
A) 1.10 ppm,singlet 
B) 2.10 ppm,triplet 
C) 3.40 ppm,triplet 
D) 4.5 ppm,singlet 
E) 5.3 ppm,doublet

Question 16

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 17

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) 5.40 ppm,doublet 
B) 1.00 ppm,multiplet 
C) 2.00 ppm,doublet 
D) 1.00 ppm,doublet 
E) 5.40 ppm,multiplet 
A) 5.40 ppm,doublet 
B) 1.00 ppm,multiplet 
C) 2.00 ppm,doublet 
D) 1.00 ppm,doublet 
E) 5.40 ppm,multiplet

Question 18

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) 3.00 ppm,doublet 
B) 3.00 ppm,triplet 
C) 5.00 ppm,triplet 
D) 1.00 ppm,doublet 
E) 5.40 ppm,multiplet 
A) 3.00 ppm,doublet 
B) 3.00 ppm,triplet 
C) 5.00 ppm,triplet 
D) 1.00 ppm,doublet 
E) 5.40 ppm,multiplet

Question 19

What is the theoretical multiplicity of the C-2 proton signal in the 1H NMR spectrum of 2-hydroxymethyl-1,3-propanediol,shown below?

Accepted Answer

A) 1 
B) 6 
C) 7 
D) 8 
E) 9 
A) 1 
B) 6 
C) 7 
D) 8 
E) 9

Question 20

Which of the following compounds would not be represented by a lone singlet in the proton NMR?

Accepted Answer

A) cyclohexane 
B) benzene 
C) dimethyl ether (CH3-O-CH3) 
D) 1,2-ethanediol 
E) none of these choices 
A) cyclohexane 
B) benzene 
C) dimethyl ether (CH3-O-CH3) 
D) 1,2-ethanediol 
E) none of these choices

Exam 9: Nuclear Magnetic Resonance and Mass Spectrometry

How many signals would you expect to find in the 1H NMR spectrum of CH3OCH2CH2OCH3?

A compound C5H10O gave the following spectral data: 1H NMR spectrum IR spectrum Doublet, δ\deltaδ 1.10 strong peak Singlet, δ\deltaδ 2.10 near 1720 cm-1 Septet, δ\deltaδ 2.50 Which is a reasonable structure for the compound?

Briefly explain how you might distinguish between the following substances by comparing their 1H-NMR spectra:

Briefly explain how you might distinguish between the following substances by comparing their 1H-NMR spectra:

An unknown compound,U,has the formula C6H4Cl2O.Elucidate the structure of U by scrutinizing its IR,1H NMR and 13C NMR spectra,shown below.

The data below from the molecular ion region of the mass spectrum of a halogen-containing compound are consistent with the presence of what halogen(s)in the original compound? intensity M+ ∙\bullet∙ 51.0 M+ ∙\bullet∙ +2 100.0 M+ ∙\bullet∙ +4 49.0

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C4H7Br? Relative integration is shown.

For the compound adamantine,how many different signals would you see in the 13C NMR? (Assume that you can see them all.)

In the structure shown,Ha and Hb are classified as:

Consider the expected 1H NMR spectrum of 1,1,3,3-tetramethylcyclopentane.Which of the following is likely to be observed?

A compound with the molecular formula C8H9BrO gave the following 1H NMR spectrum: triplet, δ\deltaδ 1.4 Quartet, δ\deltaδ 3.9 Multiplet, δ\deltaδ 7.0 (4H) There was no evidence of an -OH band in the IR spectrum.A possible structure for the compound is:

How many chemically distinct 1H NMR signals are there in the following compound?

Predict the 1H NMR spectrum of cis-1,4-cyclohexanediol if we perform the experiment in CD3OD.

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

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

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

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

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

What is the theoretical multiplicity of the C-2 proton signal in the 1H NMR spectrum of 2-hydroxymethyl-1,3-propanediol,shown below?

Which of the following compounds would not be represented by a lone singlet in the proton NMR?

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

How many signals would you expect to find in the ¹H NMR spectrum of CH₃OCH₂CH₂OCH₃?

Briefly explain how you might distinguish between the following substances by comparing their ¹H-NMR spectra:

Briefly explain how you might distinguish between the following substances by comparing their ¹H-NMR spectra:

An unknown compound,U,has the formula C₆H₄Cl₂O.Elucidate the structure of U by scrutinizing its IR,¹H NMR and ¹³C NMR spectra,shown below.

The data below from the molecular ion region of the mass spectrum of a halogen-containing compound are consistent with the presence of what halogen(s)in the original compound? intensity M⁺ $\bullet$ 51.0 M⁺ $\bullet$ +2 100.0 M⁺ $\bullet$ +4 49.0

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₄H₇Br? Relative integration is shown.

For the compound adamantine,how many different signals would you see in the ¹³C NMR? (Assume that you can see them all.)

In the structure shown,H_a and H_b are classified as:

Consider the expected ¹H NMR spectrum of 1,1,3,3-tetramethylcyclopentane.Which of the following is likely to be observed?

How many chemically distinct ¹H NMR signals are there in the following compound?

Predict the ¹H NMR spectrum of cis-1,4-cyclohexanediol if we perform the experiment in CD₃OD.

What is the theoretical multiplicity of the C-2 proton signal in the ¹H NMR spectrum of 2-hydroxymethyl-1,3-propanediol,shown below?