What are the products of each aromatic substitution reaction? b.

Verified step by step guidance

1. Identify the type of reaction: This is an electrophilic aromatic substitution reaction.
2. Recognize the reactants: Benzene (C6H6) and methyl bromide (CH3Br) in the presence of aluminum bromide (AlBr3).
3. Understand the role of the catalyst: AlBr3 acts as a Lewis acid, facilitating the formation of the electrophile.
4. Generate the electrophile: CH3Br reacts with AlBr3 to form the methyl cation (CH3+), which is the electrophile.
5. Substitute the electrophile: The methyl cation (CH3+) substitutes one of the hydrogen atoms on the benzene ring, forming methylbenzene (toluene).

Key Concepts

Aromatic Substitution Reactions

Aromatic substitution reactions involve the replacement of a hydrogen atom in an aromatic compound, such as benzene, with another substituent. These reactions typically preserve the aromaticity of the compound, which is crucial for the stability of the aromatic system. Common types include electrophilic aromatic substitution (EAS), where an electrophile attacks the aromatic ring.

Electrophilic Aromatic Substitution (EAS)

Electrophilic aromatic substitution is a specific type of aromatic substitution where an electrophile reacts with the aromatic ring. In this process, the aromatic system temporarily loses its aromaticity as the electrophile forms a sigma complex, which is then deprotonated to restore aromaticity. The reaction often requires a catalyst, such as AlBr3, to facilitate the formation of the electrophile.

Role of Catalysts in EAS

Catalysts, like AlBr3 in this reaction, are substances that increase the rate of a chemical reaction without being consumed. In EAS, AlBr3 helps generate a more reactive electrophile from CH3Br, allowing it to effectively attack the benzene ring. The presence of a catalyst is essential for overcoming the activation energy barrier associated with the reaction.