Benzene

Benzene is an aromatic hydrocarbon with the chemical formula C6H6. It is the simplest member of the aromatic family, a colorless, flammable liquid with a characteristic sweet odor. It is soluble in organic solvents but only sparingly soluble in water, and it boils at 80.1 degrees Celsius while freezing at -5.5 degrees Celsius.

Structurally, benzene consists of a planar ring of six carbon atoms with a uniform arrangement of bonds. Each carbon is sp2-hybridized, and the ring contains a delocalized pi electron system of six electrons. This delocalization, described by aromaticity and following Huckel’s rule (4n+2, with n=1), provides stability beyond that of typical alkenes.

Benzene occurs in small amounts in crude oil and is produced on an industrial scale from fossil fuels. Historically derived from coal tar, today it is primarily generated as a byproduct of petroleum refining and various chemical syntheses. It is also encountered in the environment as a volatile organic atmospheric contaminant.

As a chemical feedstock, benzene is used to manufacture a wide range of products, including styrene (for plastics and resins), phenol (and its derivatives), aniline, nylon precursors, and numerous solvents. It serves as a foundational building block for many intermediates in the chemical industry.

Safety and regulation: benzene is a known human carcinogen. Long-term exposure is associated with an increased risk of leukemia and other blood disorders. Occupational exposure limits are strictly regulated, and handling emphasizes closed systems, proper ventilation, and protective equipment. Benzene vapors are flammable and can form explosive mixtures with air.