Benzene Concepts

Which of these is an activating group?

• NH2

• NO2

• COCH3

• SO3H

Which is deactivating group?

• OH

• CHO

• CH3

• OCH3

Which of the following act as catalysis in the nitration of benzene?

• Conc. HCl

• Dil. HCl

• Conc. H₂SO₄

• Dil. H₂SO₄

What is electrophilic substitution?

• A substitution reaction in which an electrophile is substituted for the electrons in the benzene ring

• A substitution reaction in which the benzene ring is attacked by a lone pair of electrons from an electrophile

• A substitution reaction in which an electrophile is attacked by the electrons in the benzene ring

Which is least reactive in aromatic electrophilic substitution?

• Ethyl Benzene

• Anisole

• Acetophenone

• Chlorobenzene

With respect to the electrophilic aromatic substitution of benzene which of the following is not true?

• A non-aromatic intermediate is formed

• Benzene acts as an electrophile

• A proton is lost in the final step

• Resonance forms are important

What is acylation?

• Substitution of one of the hydrogen atoms of a benzene ring by an acyl group from an acyl chloride

• Addition to the benzene ring of an alkyl group from a halogenoalkane

• Addition to the benzene ring of an acyl group from an acyl chloride

What is a Friedel-Crafts reaction?

• An electrophilic substitution reaction

• A reaction to form a C-C bond to an aromatic ring

• A reaction involving a Lewis acid

Which of the following statements regarding electrophilic aromatic substitution is wrong?

• Acetyl and cyano substituents are both deactivating and m-directing.

• Alkyl groups are activating and o,p-directing.

• Ammonium groups are m-directing but amino groups are and o,p-directing.

• Chloro and methoxy substituents are both deactivating and o,p-directing.

What is the electrophile in the acylation of benzene?

• AlCl3

• CO+

• Cl+

• R-CO+