Final answer:
The starting material used in the industrial preparation of phenol is usually benzene or toluene, which are processed through the cumene process to yield phenol.
Step-by-step explanation:
The starting material used in the industrial preparation of phenol is typically benzene or toluene. In the most common process, benzene is first converted into cumene, which is then oxidized to produce cumene hydroperoxide.
Through the process known as the cumene process, cumene hydroperoxide undergoes acid-catalyzed cleavage to form phenol and acetone as a co-product. Phenol is an important chemical with various applications including as a starting material for the synthesis of plastics, dyes, drugs, resins, varnishes, and perfumes.
It is also used as a solvent and in products like soaps and shoe polish. Phenols are derivatives of benzene with one or more hydroxyl groups (-OH) directly attached to the aromatic ring, which gives them certain chemical properties such as slight acidity.