Question 1

Which of the following substituents on benzene will most likely direct an incoming electrophile to the meta position during electrophilic aromatic substitution?

Accepted Answer

A nitro group ($$\ce{NO2})$$

Question 2

Why are halogens such as bromine ($$\ce{Br}) $$considered deactivators in electrophilic aromatic substitution, yet still direct substitution to the ortho and para positions?

Accepted Answer

Their lone pairs stabilize the carbocation intermediate at ortho and para positions via resonance.

Question 3

Which of the following reagents will react as an electrophile with benzene in an electrophilic aromatic substitution reaction?

Accepted Answer

$$\ce{Cl2}$$ with $$\ce{AlCl3}$$

Question 4

In the nitration of toluene ($$\ce{C6H5CH3}$$), which position is most favored for substitution and why?

Accepted Answer

Para position, due to steric hindrance and resonance stabilization

Question 5

Which compound is most reactive in a nucleophilic aromatic substitution reaction?

Accepted Answer

A benzene ring with a nitro group ($$\ce{NO2}) at $$the ortho and para positions

Question 6

During Friedel-Crafts alkylation, why is it difficult to obtain a linear alkyl chain on benzene using a primary alkyl halide?

Accepted Answer

Carbocation rearrangement leads to branched products

Question 7

Which resonance structure best explains why nitrobenzene is less reactive than benzene in electrophilic aromatic substitution?

Accepted Answer

A resonance form with a positive charge adjacent to the nitro group

Question 8

Which of the following is NOT a factor to consider when synthesizing 1-phenylpentane from benzene?

Accepted Answer

Using alkylation for linear side chains

Question 9

In a molecule with both an activator and a deactivator substituent, which group determines the major product's position in electrophilic aromatic substitution?

Accepted Answer

The activator group

Question 10

Why does the para product predominate when isopropyl ($$\ce{iPr}) is $$the substituent on benzene?

Accepted Answer

Steric repulsion at the ortho position and preference for groups to be farthest apart

Question 11

Which of the following statements about phenols is correct?

Accepted Answer

Phenoxide ion reacts with $$\ce{CO2} at $$the ortho position due to complexation with $$\ce{Na+}$$

Question 12

Which of the following is a correct statement about aromatic side chain oxidation?

Accepted Answer

The side chain must have at least one benzylic hydrogen for oxidation to occur

Question 13

Which of the following is a requirement for nucleophilic aromatic substitution to occur?

Accepted Answer

The benzene ring must have an electron-withdrawing group

Question 14

Which of the following is a real-world application of cross-coupling reactions?

Accepted Answer

Formation of carbon-carbon bonds in pharmaceutical synthesis

Question 15

In Friedel-Crafts acylation, which reagent is typically used to generate the acylium ion?

Accepted Answer

$$\ce{AlCl3}$$

Question 16

Which of the following statements about directive effects is correct?

Accepted Answer

Ortho position between two groups is often too hindered to form a product

Question 17

Which of the following is a plausible reason why Friedel-Crafts alkylation cannot be used to synthesize linear alkyl side chains on benzene?

Accepted Answer

Carbocation rearrangement leads to branched products

Question 18

Which of the following is a plausible explanation for why electrophilic aromatic substitution is less efficient with electron-withdrawing groups?

Accepted Answer

Electron-withdrawing groups decrease the electron density of the ring, making it less reactive toward electrophiles

Question 19

Which of the following is a correct statement about the directive effects of substituents in aromatic substitution?

Accepted Answer

Electron-donating groups are ortho, para directors

Aromatic Compounds: Electrophilic and Nucleophilic Substitution, Directive Effects, and Side Chain Reactions

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