Reactions of benzene are primarily characterized by its ability to undergo electrophilic substitution, a process where an electrophile replaces one of the hydrogen atoms on the benzene ring while maintaining the aromatic stability of the compound. Common electrophilic substitution reactions include nitration, sulfonation, and halogenation, where nitro, sulfonic acid, and halogen groups are introduced, respectively. Benzene can also participate in Friedel-Crafts reactions, which involve the introduction of alkyl or acyl groups using appropriate catalysts. Although benzene can undergo addition reactions under specific conditions, such as hydrogenation to form cyclohexane, these are less common due to the stability of its aromatic structure. Overall, the reactions of benzene highlight its unique chemical properties and the influence of substituents on its reactivity and orientation in further reactions.
Which catalyst is commonly used in the halogenation of benzene?
Catalysts such as FeBr₃ or AlCl₃ are commonly used in the halogenation of benzene.
What is Friedel-Crafts alkylation?
Friedel-Crafts alkylation is a reaction where an alkyl group is introduced to the benzene ring using an alkyl halide and a Lewis acid catalyst.
What happens to benzene when it is subjected to strong oxidation?
Strong oxidation can convert benzene into carboxylic acids, such as benzoic acid, by breaking the aromatic ring.
What is the mechanism of electrophilic substitution in benzene?
The mechanism involves the formation of a sigma complex (arenium ion) when the electrophile attacks the benzene ring, followed by deprotonation to restore aromaticity.
How does benzene react with hydrogen in the presence of a catalyst?
Benzene reacts with hydrogen in the presence of a catalyst (like Pt or Ni) to undergo hydrogenation, forming cyclohexane.
What type of reaction does benzene primarily undergo?
a) Addition reaction
b) Electrophilic substitution
c) Nucleophilic substitution
d) Elimination reaction
Answer: b) Electrophilic substitution
Which of the following is a product of the nitration of benzene?
a) Toluene
b) Nitrobenzene
c) Benzoic acid
d) Phenol
Answer: b) Nitrobenzene
What catalyst is commonly used in the Friedel-Crafts alkylation of benzene?
a) H₂SO₄
b) AlCl₃
c) NaOH
d) K₂Cr₂O₇
Answer: b) AlCl₃
What is the main product when benzene is sulfonated?
a) Benzaldehyde
b) Benzenesulfonic acid
c) Nitrobenzene
d) Toluene
Answer: b) Benzenesulfonic acid
Which reaction involves the introduction of a halogen into the benzene ring?
a) Nitration
b) Halogenation
c) Sulfonation
d) Alkylation
Answer: b) Halogenation