Question 1

What is the major organic product obtained from the following reaction?

Accepted Answer

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

Question 2

What is the best choice of reagent to bring about the following transformation?

Accepted Answer

A)  [1] LiAlH4; [2]H2O 
B)  Zn (Hg), HCl 
C)  NH3, NaOH 
D)  H2, Pd-C 
A)  [1] LiAlH4; [2]H2O 
B)  Zn (Hg), HCl 
C)  NH3, NaOH 
D)  H2, Pd-C D

Question 3

What is the product of the following sequence of reactions?

Accepted Answer

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

Question 4

What is the first step in the general mechanism for electrophilic aromatic substitution?

Accepted Answer

A)  Protonation of the aromatic ring 
B)  Deprotonation of the aromatic ring 
C)  Addition of the electrophile to the aromatic ring 
D)  Loss of the electrophile from the aromatic ring 
A)  Protonation of the aromatic ring 
B)  Deprotonation of the aromatic ring 
C)  Addition of the electrophile to the aromatic ring 
D)  Loss of the electrophile from the aromatic ring

Question 5

What is the major product of the following reaction?

Accepted Answer

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

Question 6

Which of the following halides will not work as an electrophile in a Friedel-Crafts alkylation reaction?

Accepted Answer

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

Question 7

Which of the following statements about nucleophilic aromatic substitution is not true?

Accepted Answer

A)  Increasing the electronegativity of the halogen increases the reactivity of the aryl halide. 
B)  Increasing the number of electron-withdrawing groups increases the reactivity of the aryl halide. 
C)  Electron-withdrawing groups stabilize the intermediate carbanion, and lower the energy of the transition state. 
D)  When a nitro group is located meta to the halogen, the negative charge of the intermediate carbanion can be delocalized onto the NO2 group, thus stabilizing it. 
A)  Increasing the electronegativity of the halogen increases the reactivity of the aryl halide. 
B)  Increasing the number of electron-withdrawing groups increases the reactivity of the aryl halide. 
C)  Electron-withdrawing groups stabilize the intermediate carbanion, and lower the energy of the transition state. 
D)  When a nitro group is located meta to the halogen, the negative charge of the intermediate carbanion can be delocalized onto the NO2 group, thus stabilizing it.

Question 8

What is (are) the product(s) of the following reaction?

Accepted Answer

A)  Only I 
B)  Only II 
C)  Only III 
D)  Only I and II 
A)  Only I 
B)  Only II 
C)  Only III 
D)  Only I and II

Question 9

Which of the following substituents are activators in electrophilic aromatic substitution?

Accepted Answer

A)  CH3O F1F1F1S1F1F1F10 
B)  Cl F1F1F1S1F1F1F10 
C)  NO2 F1F1F1S1F1F1F10 
D)  HSO3 F1F1F1S1F1F1F10 
A)  CH3O F1F1F1S1F1F1F10 
B)  Cl F1F1F1S1F1F1F10 
C)  NO2 F1F1F1S1F1F1F10 
D)  HSO3 F1F1F1S1F1F1F10

Question 10

Rank the following compounds in order of decreasing reactivity in electrophilic aromatic substitution.

Accepted Answer

A)  II > IV > I > III 
B)  II > III > IV > I 
C)  IV > II > I > III 
D)  IV > I > II > III 
A)  II > IV > I > III 
B)  II > III > IV > I 
C)  IV > II > I > III 
D)  IV > I > II > III

Question 11

Why is the nitro group a meta director?

Accepted Answer

A)  Because it is sterically very large. 
B)  Because it adds electron density to the meta position, thus activating it. 
C)  Because it stabilizes the intermediate cation. 
D)  Because it removes more electron density from the ortho and para positions than the meta position, thus deactivating the meta position less. 
A)  Because it is sterically very large. 
B)  Because it adds electron density to the meta position, thus activating it. 
C)  Because it stabilizes the intermediate cation. 
D)  Because it removes more electron density from the ortho and para positions than the meta position, thus deactivating the meta position less.

Question 12

What are the product(s) of the following reaction?

Accepted Answer

A)  Only I 
B)  Only II 
C)  Only I and II 
D)  Only III 
A)  Only I 
B)  Only II 
C)  Only I and II 
D)  Only III

Question 13

What is the major product of the following reaction?

Accepted Answer

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

Question 14

How can polyalkylation be minimized in Friedel-Crafts alkylation?

Accepted Answer

A)  Use a large excess of alkyl halide relative to the aromatic compound. 
B)  Use a large excess of benzene relative to the alkyl halide. 
C)  Use an alkyl halide without a Lewis acid catalyst. 
D)  Use a large excess of the Lewis acid catalyst. 
A)  Use a large excess of alkyl halide relative to the aromatic compound. 
B)  Use a large excess of benzene relative to the alkyl halide. 
C)  Use an alkyl halide without a Lewis acid catalyst. 
D)  Use a large excess of the Lewis acid catalyst.

Question 15

What is the product of the following reaction?

Accepted Answer

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

Question 16

What is the electrophile in aromatic nitration?

Accepted Answer

A)  NO+ 
B)  NO2+ 
C)  NO3+ 
D)  NO2H 
A)  NO+ 
B)  NO2+ 
C)  NO3+ 
D)  NO2H

Question 17

Which set of reagents would most likely bring about the following transformation?

Accepted Answer

A)  Br2 and FeBr3 
B)  NBS and light 
C)  Br2 in CCl4 
D)  NaBr and H2O 
A)  Br2 and FeBr3 
B)  NBS and light 
C)  Br2 in CCl4 
D)  NaBr and H2O

Question 18

What is the major organic product obtained from the following reaction?

Accepted Answer

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

Question 19

What is the product of the following reaction?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  None of the above 
A)  I 
B)  II 
C)  III 
D)  None of the above

Question 20

What are the two distinct pathways for nucleophilic aromatic substitution?

Accepted Answer

A)  Addition-substitution and substitution-addition 
B)  Addition-elimination and elimination-addition 
C)  Addition-addition and elimination-elimination 
D)  Elimination-substitution and substitution-elimination 
A)  Addition-substitution and substitution-addition 
B)  Addition-elimination and elimination-addition 
C)  Addition-addition and elimination-elimination 
D)  Elimination-substitution and substitution-elimination

Exam 18: Electrophilic Aromatic Substitution

What is the major organic product obtained from the following reaction?

What is the best choice of reagent to bring about the following transformation?

What is the product of the following sequence of reactions?

What is the first step in the general mechanism for electrophilic aromatic substitution?

What is the major product of the following reaction?

Which of the following halides will not work as an electrophile in a Friedel-Crafts alkylation reaction?

Which of the following statements about nucleophilic aromatic substitution is not true?

What is (are) the product(s) of the following reaction?

Which of the following substituents are activators in electrophilic aromatic substitution?

Rank the following compounds in order of decreasing reactivity in electrophilic aromatic substitution.

Why is the nitro group a meta director?

What are the product(s) of the following reaction?

What is the major product of the following reaction?

How can polyalkylation be minimized in Friedel-Crafts alkylation?

What is the product of the following reaction?

What is the electrophile in aromatic nitration?

Which set of reagents would most likely bring about the following transformation?

What is the major organic product obtained from the following reaction?

What is the product of the following reaction?

What are the two distinct pathways for nucleophilic aromatic substitution?

Structure and Bonding

Acids and Bases

Introduction to Organic Molecules and Functional Groups

Alkanes

Stereochemistry

Understanding Organic Reactions

Alkyl Halides and Nucleophilic Substitution

Alkyl Halides and Elimination Reactions

Alcohols, Ethers and Epoxides

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Mass Spectrometry and Infrared Spectroscopy

Nuclear Magnetic Resonance Spectroscopy

Radical Reactions

Conjugation, Resonance, and Dienes

Benzene and Aromatic Compounds

Carboxylic Acids and the Acidity of the O-H Bond

Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Aldehydes and Ketones Nucleophilic Addition

Carboxylic Acids and Derivatives

Substitution Reactions of Carbonyl Compounds at the Alpha-Carbon

Carbonyl Condensation Reactions

Amines

Carbon-Carbon Bond Forming Reactions in Organic Synthesis

Pericyclic Reactions

Carbohydrates

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