nhexán

n-hexane, or normal hexane, is a straight-chain alkane with six carbon atoms and the formula C6H14. It is the unbranched isomer of hexane and the principal member of the hexane family used as a nonpolar solvent. At room temperature it is a colorless, highly flammable liquid with a characteristic odor.

Production and occurrence

It is produced mainly during petroleum refining and from natural gas liquids. It is a common component of industrial hydrocarbon solvents and is present in trace amounts in gasoline and other fuels.

Properties

Boiling point 68.7 °C; melting point around -95 °C; density about 0.66 g/mL at 20 °C; insoluble in water and miscible with many organic solvents. It is nonpolar and has a relatively low viscosity, evaporating readily at room temperature.

Applications

n-Hexane is widely used as a solvent in the extraction of edible oils from seeds and vegetables, in cleaning and adhesive formulations, and in printing inks and paints. It is also used in chromatography as a nonpolar eluent and serves as a feedstock in the production of certain chemicals.

Safety and environmental considerations

It is flammable and forms hazardous vapors. Inhalation of high concentrations can cause dizziness, euphoria, or narcosis; long-term exposure has been linked to peripheral neuropathy due to metabolites such as 2,5-hexanedione. Proper ventilation, storage away from ignition sources, and protective equipment are advised. Environmentally, n-hexane has moderate aquatic toxicity and tends to volatilize; spills should be contained to prevent groundwater and air contamination.

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