Benzene

Benzene is a colorless liquid with a sweet odor. It evaporates into the air very quickly and dissolves slightly in water. Because it contains only carbon and hydrogen atoms, benzene is classed as a hydrocarbon.

Benzene is a natural constituent of petroleum and is one of the elementary petrochemicals. Due to the cyclic continuous pi bonds between the carbon atoms, benzene is classed as an aromatic hydrocarbon. Benzene is a colorless and highly flammable liquid with a sweet smell, and is partially responsible for the aroma of gasoline.

Many important chemical compounds are derived from benzene by replacing one or more of its hydrogen atoms with another functional group. Examples of simple benzene derivatives are phenol, toluene, and aniline. Linking benzene rings gives biphenyl, C6H5–C6H5. Further loss of hydrogen gives “fused” aromatic hydrocarbons, such as naphthalene, anthracene, phenanthrene, and pyrene.