Chlorobenzene is prepared commercially by

Chlorobenzene is prepared commercially through a process known as chlorination. There are several methods for producing chlorobenzene, but one of the most common industrial methods is the direct chlorination of benzene. Here is a general overview of the process:

Feedstock preparation: Benzene, which is derived from petroleum or other sources, is usually the starting material. It undergoes purification to remove impurities that may interfere with the chlorination process.

Chlorination reaction: The purified benzene is then mixed with chlorine gas (Cl2) in the presence of a catalyst, typically an iron or iron(III) chloride catalyst. The reaction occurs at elevated temperatures (usually around 300-400°C) and is typically carried out in the liquid or vapor phase.

The chlorination reaction can be represented by the following equation:
C6H6 + Cl2 -> C6H5Cl + HCl

In this reaction, one chlorine atom replaces one of the hydrogen atoms in benzene to form chlorobenzene, along with the production of hydrogen chloride (HCl) as a byproduct.

Separation and purification: After the chlorination reaction, the mixture is cooled and undergoes several separation and purification steps. These steps may include distillation, extraction, and other techniques to separate chlorobenzene from the reaction mixture and remove impurities.

Further processing: The obtained chlorobenzene can be further processed for various applications. It is commonly used as an intermediate in the production of other chemicals, such as pesticides, dyes, and pharmaceuticals.

It's important to note that industrial processes may vary, and there might be alternative methods or variations used for the commercial production of chlorobenzene. However, the general principles outlined above provide a typical overview of the process.