Heptane or n-heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16, and is one of the main components of gasoline (petrol). When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale (the 100 point is 100% iso-octane). Octane number equates to the anti-knock qualities of a comparison mixture of heptane and isooctane which is expressed as the percentage of isooctane in heptane and is listed on pumps for alkane (petrol) dispensed globally.


Molar Weight100.2 g/mol
Melting Point−90.54 °C
Boiling Point98 °C
Flash Point-3.9 °C
Density0.684 g/mL at 20 °C
FormsFlammable, Liquid (clear), Colourless

Uses and Applications

Key applications

  • Adhesives and Sealants
  • Solvents
  • Pharmaceuticals
  • Personal care


  • Rubber
  • Coatings & Construction
  • Cosmetics
  • Oil & Gas

Synonyms: Heptane I n-heptane

Chemical Formula: C7H16

CAS Number: 142-82-5