CH3CH2CH2CH3

CH3CH2CH2CH3 is the structural representation of n-butane, a straight-chain alkane with four carbon atoms. Its molecular formula is C4H10. It is one of the two structural isomers of C4H10; the other is isobutane (2-methylpropane).

In its pure form, n-butane is a colorless, flammable gas at room temperature and pressure, becoming a liquid under sufficient pressure. It is nonpolar and only sparingly soluble in water, but readily dissolves in many organic solvents. Its boiling point is about -0.5°C, and it condenses into a liquid under modest pressure.

Production and occurrence: N-butane is obtained from petroleum fractions by fractional distillation and from natural gas processing; it is a major component of liquefied petroleum gas (LPG) mixtures, often blended with propane and isobutane.

Applications: It serves as a fuel for portable stoves and lighters, a propellant in aerosol formulations, and a feedstock for chemical synthesis and petrochemical processing. It is also used in refineries for alkylation to produce higher-octane fuels.

Safety: As with other alkanes, n-butane is highly flammable and forms flammable mixtures with air. Leaking gas may accumulate in confined spaces; proper ventilation is required. Handling requires avoiding ignition sources and storage in appropriate pressurized containers.