Question 1

Which of the following statements best describes the effect of two electron-donating groups (EDGs) that are meta to each other on a benzene ring during electrophilic aromatic substitution?

Accepted Answer

They compete, and the EDG that is more activating dominates, directing substitution ortho and para to itself.

Question 2

In the presence of an electron-donating group (EDG) para to an electron-withdrawing group (EWG) on a benzene ring, where is electrophilic substitution most likely to occur?

Accepted Answer

Ortho to the EDG and meta to the EWG.

Question 3

Which of the following is the major product when nitration occurs on a benzene ring with a methoxy group (an EDG) at the para position to a nitro group (an EWG)?

Accepted Answer

Nitration occurs ortho to the methoxy group.

Question 4

What is the effect of two EDGs that are para to each other on a benzene ring during electrophilic aromatic substitution?

Accepted Answer

They create a mixture of products ortho to each EDG, with the major product ortho to the stronger EDG.

Question 5

Which of the following is the correct order of reactivity for the following substituents in electrophilic aromatic substitution: $$-NO_2$, $$-$$OCH_3$$, $$-CH_3$, -$$COOH$$?

Accepted Answer

$$-$$OCH_3$$ \u003e -CH_3$ \u003e -COOH \u003e -NO_2$

Question 6

Which of the following best describes the mechanism of the Birch reduction?

Accepted Answer

It is a dissolved electron reduction using sodium or lithium in liquid ammonia, resulting in a non-conjugated diene.

Question 7

During the Birch reduction of anisole (methoxybenzene), which positions on the ring are reduced?

Accepted Answer

The meta positions relative to the methoxy group.

Question 8

Which of the following is a key intermediate in the mechanism of electrophilic aromatic substitution?

Accepted Answer

A carbocation (arenium ion)

Question 9

A benzene ring has a methyl group at the para position to a nitro group. Which group will dominate the directing effects during bromination?

Accepted Answer

The methyl group, because it is an EDG and activates the ring.

Question 10

Which of the following best explains why electron-withdrawing groups (EWGs) deactivate the benzene ring toward electrophilic aromatic substitution?

Accepted Answer

EWGs withdraw electron density from the ring, making it less nucleophilic and less reactive toward electrophiles.

Question 11

Which of the following is the correct product for the nitration of toluene?

Accepted Answer

A mixture of ortho and para nitrotoluene, with the para product predominating.

Question 12

Which of the following is the correct sequence of steps in the mechanism of electrophilic aromatic substitution?

Accepted Answer

Aromatic ring attacks electrophile, formation of arenium ion, deprotonation to restore aromaticity.

Question 13

Which of the following substituents is most likely to direct incoming electrophiles to the ortho and para positions during electrophilic aromatic substitution?

Accepted Answer

$$-$$OCH_3$$

Question 14

Which of the following best describes the product of the Birch reduction of benzene?

Accepted Answer

1,4-cyclohexadiene

Question 15

A benzene ring has a nitro group at the meta position to a methyl group. Where will bromination most likely occur?

Accepted Answer

Ortho and para to the methyl group

Question 16

Which of the following is a common misconception about the Birch reduction?

Accepted Answer

It produces a conjugated diene as the major product.

Aromaticity and Reactions of Aromatic Compounds: Electrophilic Aromatic Substitution and Birch Reduction

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