Question 1

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

Question 2

A compound with the molecular formula C10H13Cl gave the following 1H NMR spectrum: singlet,$\delta$ 1.6
Singlet,$\delta$ 3.1
Multiplet,$\delta$ 7.2 (5H)
The most likely 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 3

How many 13C signals would 1,3-dichlorobenzene give?

Accepted Answer

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

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

Question 5

What is the molecular formula of this compound? m/z intensity
78 M+$\bullet$ 10.00
79 1
80 3.3
81 0.3

Accepted Answer

A) C6H6 
B) C3H5Cl 
C) C6H8 
D) C6H9 
E) C3H7Cl 
A) C6H6 
B) C3H5Cl 
C) C6H8 
D) C6H9 
E) C3H7Cl

Question 6

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C8H15ClO3,which shows a characteristic stretch in the IR around 1750 cm-1 but not around 3500 cm-1,and a characteristic peak at 173 ppm in the 13C-NMR? Relative integration is shown.

Accepted Answer

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

Question 7

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C6H12O2? Relative integration is shown.

Accepted Answer

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

Question 8

Which compound below would give rise to 4 signals in the proton NMR spectrum and 4 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) More than one of the above. 
A) I 
B) II 
C) III 
D) IV 
E) More than one of the above.

Question 9

If all the protons of 1-fluoropentane could be discerned,which would you expect to be at the lowest field in the 1H NMR spectrum of this compound?

Accepted Answer

A) Protons on carbon I 
B) Protons on carbon II 
C) Protons on carbon III 
D) Protons on carbon IV 
E) Protons on carbon V 
A) Protons on carbon I 
B) Protons on carbon II 
C) Protons on carbon III 
D) Protons on carbon IV 
E) Protons on carbon V

Question 10

A compound with the molecular formula C10H14 gave the following 1H NMR spectrum: doublet,$\delta$1.2
Singlet,$\delta$ 2.3
Septet,$\delta$ 2.8
Multiplet,$\delta$ 7.1
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 11

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C8H16O? Relative integration is shown.

Accepted Answer

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

Question 12

A compound that would show two triplets and a septet in the 1H NMR spectrum could be:

Accepted Answer

A) 3-ethylpentane 
B) 2-bromopropane 
C) chlorocyclopropane 
D) 1-iodopropane 
E) none of these choices 
A) 3-ethylpentane 
B) 2-bromopropane 
C) chlorocyclopropane 
D) 1-iodopropane 
E) none of these choices

Question 13

Predict the 1H NMR spectrum of 2-chloroethanal,CH2ClCHO.

Accepted Answer

Question 14

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 15

The predicted ratio of the relative peak sizes in a quintet signal would be about 1:3:5:3:1.

Accepted Answer

A) True 
 B)False

Question 16

Compounds that contain a benzylic carbon will often show a peak with a m/z of 91 in a mass spectrometry experiment.

Accepted Answer

nuclear ma

Question 17

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 18

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C9H18O2 and characteristic 13C-NMR peaks at 11.3,21.6,25.3,49.4,67.1,and 175.5 ppm? Relative integration is shown.

Accepted Answer

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

Question 19

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

Accepted Answer

A) 2 
B) 3 
C) 4 
D) 5 
E) None of these choices. 
A) 2 
B) 3 
C) 4 
D) 5 
E) None of these choices.

Question 20

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

Exam 9: Nuclear Magnetic Resonance and Mass Spectrometry

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

A compound with the molecular formula C10H13Cl gave the following 1H NMR spectrum: singlet, δ\deltaδ 1.6 Singlet, δ\deltaδ 3.1 Multiplet, δ\deltaδ 7.2 (5H) The most likely structure for the compound is:

How many 13C signals would 1,3-dichlorobenzene give?

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

What is the molecular formula of this compound? m/z intensity 78 M+ ∙\bullet∙ 10.00 79 1 80 3.3 81 0.3

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C8H15ClO3,which shows a characteristic stretch in the IR around 1750 cm-1 but not around 3500 cm-1,and a characteristic peak at 173 ppm in the 13C-NMR? Relative integration is shown.

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C6H12O2? Relative integration is shown.

Which compound below would give rise to 4 signals in the proton NMR spectrum and 4 signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)

If all the protons of 1-fluoropentane could be discerned,which would you expect to be at the lowest field in the 1H NMR spectrum of this compound?

A compound with the molecular formula C10H14 gave the following 1H NMR spectrum: doublet, δ\deltaδ 1.2 Singlet, δ\deltaδ 2.3 Septet, δ\deltaδ 2.8 Multiplet, δ\deltaδ 7.1 A possible structure for the compound is:

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C8H16O? Relative integration is shown.

A compound that would show two triplets and a septet in the 1H NMR spectrum could be:

Predict the 1H NMR spectrum of 2-chloroethanal,CH2ClCHO.

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

The predicted ratio of the relative peak sizes in a quintet signal would be about 1:3:5:3:1.

Compounds that contain a benzylic carbon will often show a peak with a m/z of 91 in a mass spectrometry experiment.

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

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C9H18O2 and characteristic 13C-NMR peaks at 11.3,21.6,25.3,49.4,67.1,and 175.5 ppm? Relative integration is shown.

For the compound dimedone,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?

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 ¹³C signals would 1,3-dichlorobenzene give?

What is the molecular formula of this compound? m/z intensity 78 M⁺ $\bullet$ 10.00 79 1 80 3.3 81 0.3

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₈H₁₅ClO₃,which shows a characteristic stretch in the IR around 1750 cm^-1 but not around 3500 cm^-1,and a characteristic peak at 173 ppm in the ¹³C-NMR? Relative integration is shown.

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₆H₁₂O₂? Relative integration is shown.

If all the protons of 1-fluoropentane could be discerned,which would you expect to be at the lowest field in the ¹H NMR spectrum of this compound?

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₈H₁₆O? Relative integration is shown.

A compound that would show two triplets and a septet in the ¹H NMR spectrum could be:

Predict the ¹H NMR spectrum of 2-chloroethanal,CH₂ClCHO.

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

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

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₉H₁₈O₂ and characteristic ¹³C-NMR peaks at 11.3,21.6,25.3,49.4,67.1,and 175.5 ppm? Relative integration is shown.