Benzene Concepts

Front

What is benzene?

Back

Benzene is a colorless, flammable liquid with a sweet odor and is a fundamental aromatic hydrocarbon with the formula C6H6.

Front

What is an activating group in electrophilic aromatic substitution?

Back

An activating group is a substituent that increases the electron density of the aromatic ring, making it more reactive towards electrophiles. Example: -NH2 (amino group).

Front

What is a deactivating group in electrophilic aromatic substitution?

Back

A deactivating group is a substituent that decreases the electron density of the aromatic ring, making it less reactive towards electrophiles. Example: -CHO (aldehyde group).

Front

What is electrophilic aromatic substitution?

Back

Electrophilic aromatic substitution is a reaction where an electrophile replaces a hydrogen atom on an aromatic ring.

Front

What is the role of a Lewis acid in Friedel-Crafts reactions?

Back

A Lewis acid acts as a catalyst that helps generate the electrophile needed for the reaction.

Front

What is the electrophile in the acylation of benzene?

Back

The electrophile in the acylation of benzene is R-CO+, where R is an alkyl group.

Front

What is the significance of resonance forms in electrophilic aromatic substitution?

Back

Resonance forms stabilize the carbocation intermediate formed during the reaction, facilitating the substitution process.

Front

What is a Friedel-Crafts reaction?

Back

A Friedel-Crafts reaction is an electrophilic substitution reaction that introduces an alkyl or acyl group into an aromatic ring.

Front

What happens to the aromaticity of benzene during electrophilic aromatic substitution?

Back

The aromaticity is temporarily lost during the formation of the non-aromatic carbocation intermediate but is restored after the substitution.

Front

What is the difference between ortho, meta, and para substitution?

Back

Ortho substitution occurs at adjacent carbon atoms, meta substitution occurs with one carbon in between, and para substitution occurs opposite each other on the ring.