C6H5CH2CH3

Ethylbenzene (C6H5CH2CH3, molecular formula C8H10) is an aromatic hydrocarbon consisting of a benzene ring with an ethyl substituent. It is a colorless to pale-yellow liquid at room temperature with a characteristic sweet, aromatic odor. It is flammable and its vapors form explosive mixtures with air; handling requires adequate ventilation and avoidance of ignition sources. It is relatively immiscible with water and is soluble in many organic solvents. Its boiling point is about 136°C and its density is near 0.867 g/cm3 at 20°C.

Industrial production and uses: Ethylbenzene is produced primarily by the alkylation of benzene with ethene (ethylene) using solid-acid or traditional catalysts. It is the main feedstock for the production of styrene via dehydrogenation: ethylbenzene → styrene (C8H8) + H2. Styrene is a key monomer for polystyrene and various copolymers. Ethylbenzene is also used as a solvent and as an intermediate in the synthesis of other chemicals.

Safety and environmental notes: Exposure to ethylbenzene can irritate the skin and eyes; inhalation may affect the nervous system. It is a volatile organic compound and a potential environmental contaminant; releases should be controlled to prevent air and water pollution. Spills should be contained and absorbed, and contaminated soils should be treated to reduce impacts. Handling and storage require appropriate containment, grounding, and ventilation in well-ventilated areas away from ignition sources.