Question 1

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

Accepted Answer

A) 3 
B) 4 
C) 5 
D) 6 
E) None of these choices. 
A) 3 
B) 4 
C) 5 
D) 6 
E) None of these choices. C

Question 2

All of the hydrogen atoms in a molecule of cyclohexane are homotopic.

Accepted Answer

A) True 
 B)False  True

Question 3

An unknown compound,L,has the formula C5H10O2.Elucidate the structure of L by scrutinizing its IR,1H NMR and 13C NMR spectra,shown below.

Accepted Answer

Methyl butyrate

Question 4

Which compound below would not give rise to 4 signals in the proton NMR spectrum and 3 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) All of these choices fit the criteria. 
A) I 
B) II 
C) III 
D) IV 
E) All of these choices fit the criteria.

Question 5

A compound with the molecular formula C3H6Cl2 gave a 1H NMR spectrum consisting only of a triplet centered at $\delta$3.7 and a quintet centered at $\delta$ 2.2.The most likely structure for the compound is:

Accepted Answer

A) CH3CH2CHCl2 
B) CH3CHClCH2Cl 
C) ClCH2CHClCH3 
D) ClCH2CH2CH2Cl 
E) CH3CCl2CH3 
A) CH3CH2CHCl2 
B) CH3CHClCH2Cl 
C) ClCH2CHClCH3 
D) ClCH2CH2CH2Cl 
E) CH3CCl2CH3

Question 6

The broadband proton-decoupled 13C NMR spectrum of a hexyl chloride exhibits five signals.Which of these structures could be the correct one for the compound?

Accepted Answer

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

Question 7

Which compound below would give rise to 3 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) None of these choices. 
A) I 
B) II 
C) III 
D) IV 
E) None of these choices.

Question 8

Which is the likely molecular ion (M+$\bullet$)?

Accepted Answer

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

Question 9

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C9H10O2? Relative integration is shown.

Accepted Answer

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

Question 10

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C6H10O2? The 13C-NMR shows characteristic chemical shifts at 22.3,31.1,117.3,157.7,and 171.6 ppm.Relative integration is shown.

Accepted Answer

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

Question 11

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,doublet 
B) 2.00 ppm,singlet 
C) 2.00 ppm,triplet 
D) 2.00 ppm,doublet 
E) 1.00 ppm,triplet 
A) 1.00 ppm,doublet 
B) 2.00 ppm,singlet 
C) 2.00 ppm,triplet 
D) 2.00 ppm,doublet 
E) 1.00 ppm,triplet

Question 12

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

Question 13

The 1H NMR spectrum of which of the compounds below,all of formula C7H12O2,would consist of two singlets only?

Accepted Answer

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

Question 14

How many 1H NMR signals would trans-1,2-dichlorocyclopropane give?

Accepted Answer

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

Question 15

Predict the number of signals in the 1H NMR spectrum of 2-methyl-2-pentanol.

Accepted Answer

Question 16

How many 1H NMR signals would you expect from this compound?

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 compound below would give rise to 4 signals in the proton NMR spectrum and 6 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 these choices. 
A) I 
B) II 
C) III 
D) IV 
E) More than one of these choices.

Question 18

Predict the base peak for 2-chloro-2-methylpropane,

Accepted Answer

A) m/z 15 
B) m/z 92 
C) m/z 43 
D) m/z 57 
E) m/z 77 
A) m/z 15 
B) m/z 92 
C) m/z 43 
D) m/z 57 
E) m/z 77

Question 19

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C11H14O2? Looking at the 13C-NMR you notice a peak at 174 ppm.Relative integration is shown.

Accepted Answer

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

Question 20

Name two rapid processes that occur in organic molecules.

Accepted Answer

Rotation about C-C s

Exam 9: Nuclear Magnetic Resonance and Mass Spectrometry

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

All of the hydrogen atoms in a molecule of cyclohexane are homotopic.

An unknown compound,L,has the formula C5H10O2.Elucidate the structure of L by scrutinizing its IR,1H NMR and 13C NMR spectra,shown below.

Which compound below would not give rise to 4 signals in the proton NMR spectrum and 3 signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)

A compound with the molecular formula C3H6Cl2 gave a 1H NMR spectrum consisting only of a triplet centered at δ\deltaδ 3.7 and a quintet centered at δ\deltaδ 2.2.The most likely structure for the compound is:

The broadband proton-decoupled 13C NMR spectrum of a hexyl chloride exhibits five signals.Which of these structures could be the correct one for the compound?

Which compound below would give rise to 3 signals in the proton NMR spectrum and 4 signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)

Which is the likely molecular ion (M+ ∙\bullet∙ )?

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C9H10O2? Relative integration is shown.

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C6H10O2? The 13C-NMR shows characteristic chemical shifts at 22.3,31.1,117.3,157.7,and 171.6 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?

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

The 1H NMR spectrum of which of the compounds below,all of formula C7H12O2,would consist of two singlets only?

How many 1H NMR signals would trans-1,2-dichlorocyclopropane give?

Predict the number of signals in the 1H NMR spectrum of 2-methyl-2-pentanol.

How many 1H NMR signals would you expect from this compound?

Which compound below would give rise to 4 signals in the proton NMR spectrum and 6 signals in the carbon NMR spectrum? (Assume you can separate and see all peaks.)

Predict the base peak for 2-chloro-2-methylpropane,

What is the structure of the compound in the following 1H-NMR spectrum with the molecular formula C11H14O2? Looking at the 13C-NMR you notice a peak at 174 ppm.Relative integration is shown.

Name two rapid processes that occur in organic molecules.

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

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

An unknown compound,L,has the formula C₅H₁₀O₂.Elucidate the structure of L by scrutinizing its IR,¹H NMR and ¹³C NMR spectra,shown below.

A compound with the molecular formula C₃H₆Cl₂ gave a ¹H NMR spectrum consisting only of a triplet centered at $\delta$ 3.7 and a quintet centered at $\delta$ 2.2.The most likely structure for the compound is:

The broadband proton-decoupled ¹³C NMR spectrum of a hexyl chloride exhibits five signals.Which of these structures could be the correct one for the compound?

Which is the likely molecular ion (M⁺ $\bullet$ )? $Which is the likely molecular ion (M<sup>+</sup> \bullet )?$

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₉H₁₀O₂? Relative integration is shown.

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₆H₁₀O₂? The ¹³C-NMR shows characteristic chemical shifts at 22.3,31.1,117.3,157.7,and 171.6 ppm.Relative integration is shown.

The ¹H NMR spectrum of which of the compounds below,all of formula C₇H₁₂O₂,would consist of two singlets only?

How many ¹H NMR signals would trans-1,2-dichlorocyclopropane give?

Predict the number of signals in the ¹H NMR spectrum of 2-methyl-2-pentanol.

How many ¹H NMR signals would you expect from this compound?

What is the structure of the compound in the following ¹H-NMR spectrum with the molecular formula C₁₁H₁₄O₂? Looking at the ¹³C-NMR you notice a peak at 174 ppm.Relative integration is shown.