$$\text{SO}_3$$ and $$\text{H}_2\text{SO}_4$$

$$\text{H}_2\text{N-NH}_2$$ and $$\text{NaOH}$$

Question 1

Which of the following is the correct electrophile generated during the nitration of benzene?

Accepted Answer

$$	ext{NO}_2^+$$

Question 2

What is the major product when benzene reacts with bromine ($$	ext{Br}_2) in $$the presence of iron(III) bromide ($$	ext{FeBr}_3$$)?

Accepted Answer

Bromobenzene

Question 3

Which of the following substituents is a strong activator and an ortho/para director in aromatic electrophilic substitution?

Accepted Answer

$$	ext{-NH}_2$$

Question 4

Why do Friedel-Crafts alkylation reactions often fail with benzene rings containing strong electron-withdrawing groups?

Accepted Answer

The ring is deactivated and cannot stabilize the carbocation intermediate.

Question 5

Which of the following is the rate-determining step in the general mechanism for aromatic electrophilic substitution?

Accepted Answer

Formation of the arenium ion (sigma complex)

Question 6

What is the effect of a methyl group ($$	ext{-CH}_3) on $$the rate and orientation of nitration of benzene?

Accepted Answer

Increases the rate and directs substitution to the ortho and para positions

Question 7

Which limitation is NOT associated with Friedel-Crafts alkylation reactions?

Accepted Answer

Formation of acylium ions

Question 8

What is the product of the reduction of an aryl ketone using the Clemmensen reduction?

Accepted Answer

Arene (alkylbenzene)

Question 9

Which of the following statements about halogen substituents on benzene is correct?

Accepted Answer

Halogens are weak deactivators and ortho/para directors.

Question 10

Which mechanism is responsible for nucleophilic aromatic substitution in compounds with strong electron-withdrawing groups?

Accepted Answer

S$$_NAr $$mechanism

Question 11

What is the major product when toluene ($$	ext{C}_6	ext{H}_5	ext{CH}_3) is $$nitrated with $$	ext{HNO}_3$$ and $$	ext{H}_2	ext{SO}_4$$?

Accepted Answer

Ortho- and para-nitrotoluene

Question 12

Which of the following is a consequence of resonance effects in aromatic electrophilic substitution?

Accepted Answer

Stabilization of the arenium ion intermediate

Question 13

Which reagent is used for the sulfonation of benzene?

Accepted Answer

$$	ext{SO}_3$$ and $$	ext{H}_2	ext{SO}_4$$

Question 14

Which of the following is the correct order of radical stability?

Accepted Answer

Methyl \u003c 1° \u003c 2° \u003c 3° \u003c benzylic ≈ allylic

Question 15

What is the effect of an electron-donating group on the rate of aromatic electrophilic substitution?

Accepted Answer

Increases the rate

Question 16

Which product is formed when benzene reacts with acetyl chloride ($$	ext{CH}_3	ext{COCl}) $$and aluminum chloride ($$	ext{AlCl}_3$$)?

Accepted Answer

Acetophenone

Question 17

Which of the following is a limitation of Friedel-Crafts alkylation but NOT acylation?

Accepted Answer

Polyalkylation

Question 18

What is the major product when ethylbenzene is oxidized with potassium permanganate ($$	ext{KMnO}_4$$)?

Accepted Answer

Benzoic acid

Question 19

Which reagent is used for the Wolff-Kishner reduction of aryl ketones?

Accepted Answer

$$	ext{H}_2	ext{N-NH}_2$$ and $$	ext{NaOH}$$

Question 20

Which of the following best explains why halogen substituents are ortho/para directors but deactivators in aromatic electrophilic substitution?

Accepted Answer

Halogens donate electrons by resonance but withdraw electrons by induction.

Aromatic Compounds: Electrophilic Substitution and Reactivity (Chapter 15 Study Guide)

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