Question 1

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

Accepted Answer

Formation of the arenium ion (σ-complex)

Question 2

What is the major product when benzene reacts with bromine in the presence of FeBr3?

Accepted Answer

Bromobenzene

Question 3

Which substituent on a benzene ring is a strong activator and an ortho/para director?

Accepted Answer

-NH2

Question 4

Why do Friedel-Crafts alkylation reactions often result in polyalkylation, but Friedel-Crafts acylation does not?

Accepted Answer

The acyl group deactivates the ring toward further substitution

Question 5

Which of the following is a limitation of Friedel-Crafts alkylation?

Accepted Answer

Carbocation rearrangement can occur, leading to unexpected products

Question 6

What is the electrophile generated in the nitration of benzene?

Accepted Answer

$$	ext{NO}_2^+$$

Question 7

Which of the following substituents is a meta director and strongly deactivates the benzene ring?

Accepted Answer

-NO2

Question 8

What is the product of the oxidation of the benzylic side chain of toluene with KMnO4?

Accepted Answer

Benzoic acid

Question 9

Which mechanism is involved in nucleophilic aromatic substitution (S_NAr) reactions?

Accepted Answer

Addition-elimination mechanism

Question 10

Which reagent is used in the reduction of aryl ketones to alkanes via the Clemmensen reduction?

Accepted Answer

Zn(Hg) in concentrated HCl

Question 11

What is the effect of a nitro group (-NO2) on the rate and orientation of aromatic electrophilic substitution?

Accepted Answer

Strongly decreases the rate and directs substitution to the meta position

Question 12

Which of the following is true about the reactivity of halobenzenes in electrophilic aromatic substitution?

Accepted Answer

Halogens are ortho/para directors but deactivate the ring

Question 13

What is the major product when anisole ($$	ext{C}_6	ext{H}_5	ext{OCH}_3) is $$nitrated?

Accepted Answer

Para-nitroanisole

Question 14

Which of the following best explains why electron-donating groups increase the rate of aromatic electrophilic substitution?

Accepted Answer

They stabilize the arenium ion intermediate via resonance

Question 15

Which of the following is a synthetic application of Friedel-Crafts acylation?

Accepted Answer

Preparation of aryl ketones

Question 16

What is the effect of an -OH group on the reactivity and orientation of aromatic electrophilic substitution?

Accepted Answer

Strongly activates the ring and directs substitution to ortho/para positions

Question 17

Which of the following is the correct order of relative rates for aromatic electrophilic substitution for the following compounds: benzene, toluene, anisole?

Accepted Answer

Anisole \u003e Toluene \u003e Benzene

Question 18

Which of the following statements about the Birch reduction is correct?

Accepted Answer

It reduces aromatic rings to non-aromatic cyclohexadienes

Question 19

What is the major product when methylbenzene (toluene) is treated with NBS and light?

Accepted Answer

Benzyl bromide

Question 20

Which of the following best describes the effect of resonance in the transition state of aromatic electrophilic substitution?

Accepted Answer

Resonance stabilizes the arenium ion intermediate, lowering activation energy

Aromatic Electrophilic Substitution and Reactivity of Aromatic Compounds

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