Step 1: Reaction of acetic acid with thionyl chloride.
Acetic acid reacts with thionyl chloride (SOCl\(_2\)) to form acetyl chloride.
Step 2: Friedel-Crafts acylation.
Acetyl chloride reacts with benzene in the presence of AlCl\(_3\) to form acetophenone.
Step 3: Hydrolysis.
The next reaction involves hydrolysis of the nitrile group to form a carboxylic acid, yielding the final product as \( \text{C}_6\text{H}_5\text{COOH} \) (benzoic acid).