heptan

Heptane, or n-heptane for the normal straight-chain form, is an aliphatic hydrocarbon with the formula C7H16. It is part of the saturated acyclic hydrocarbons known as alkanes. For C7H16, nine constitutional isomers exist, including the linear n-heptane and several branched derivatives.

Occurrence and production: Heptane occurs naturally in crude oil and is produced commercially by distillation and refining of petroleum fractions. It is a common component of gasoline and is also manufactured as a solvent for laboratory and industrial use.

Physical properties: Heptane is a colorless, volatile liquid with low water solubility. It is nonpolar and dissolves readily in many organic solvents. The straight-chain isomer has a boiling point near 98°C; branched isomers have similar, slightly different boiling points and densities.

Uses: It is widely used as a solvent in chemical synthesis, extraction, and cleaning applications. It serves as a calibration standard in gas chromatography and as a component of fuels and octane rating discussions.

Safety and environmental: Heptane is highly flammable. Vapors can form explosive mixtures with air, and exposure may affect the central nervous system; prolonged contact with skin or eyes can cause irritation. It should be handled with good ventilation, away from heat and ignition sources, and disposed of according to regulations. It is a volatile organic compound that can contribute to air pollution if released.