Question

Benzene reacts with acetyl chloride in presence of anhydrous aluminum chloride to form:
$(a)$ Acetophenone
$(b)$ Phenyl acetate
$(c)$ Chlorobenzene
$(d)$ Benzoic acid

Answer 1

The above reaction is a Friedel-craft reaction, it is a coupling reaction where electrophilic aromatic substitution takes place where an electrophile group is attached to the aromatic ring.

Complete answer:
The benzene reacts with acetyl chloride in presence of anhydrous aluminum chloride to form acetophenone. The reaction is a Friedel-craft reaction in which an acyl group is attached to the aromatic ring. The Friedel-craft acylation involves addition of acid chloride with the help of Lewis acid catalyst aluminum chloride $AlC{L_3}$ . In the Friedel-craft acylation reaction, ketone is formed as the main product.
The conversion of benzene into acetophenone is an electrophilic substitution, where an acyl group is attached to the benzene ring. In this reaction, first the Lewis acid catalyst reacts with acyl chloride to form a complex where the acyl chloride loses its chloride ion and forms acylium ion $RC{O^ + }$ which acts as an electrophile and stabilizes by resonance.
The reaction is as follow:

The acylium ion then attacks the benzene ring forming an intermediate complex which deprotonate and proton joins with the chloride to form hydrochloric acid.
Option: $(a)$ Acetophenone.

Note:
In Friedel craft acylation reaction, acid anhydride can also be used in place of acyl halide. In Friedel-craft acylation reaction benzene reacts with acid anhydride in presence of anhydrous aluminum chloride to form acetophenone and acetic acid.