Properties of Heptane (C7H16)
Heptane is a hydrocarbon compound with the chemical formula C7H16. It is a flammable, colorless liquid that is one of the many isomers of octane. Heptane is commonly used as a fuel additive and as a standard in octane rating to measure the antiknock quality of gasoline.
The following table provides a comprehensive list of heptane properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).
Click on the icon to switch between Metric and Imperial units.
| Physical Properties | Metric |
|---|---|
| Molar Mass | 100.2 g/mol |
| Density | 680 kg/m3 |
| Dynamic Viscosity | 0.409 mPa·s |
| Surface Tension | 19.7 mN/m |
| Thermal Properties | Metric |
| Melting Point | -90.5 °C |
| Boiling Point | 98.4 °C |
| Thermal Conductivity | 0.124 W/m·K |
| Specific Heat Capacity (Cp) | 2245 J/kg·K |
| Coefficient of Thermal Expansion (αV) | 1.26×10-3 1/°C |
| Vapor Pressure | 4.7 kPa |
| Critical Constants | Metric |
| Critical Temperature (Tc) | 267 °C |
| Critical Pressure (Pc) | 2.74 MPa |
| Critical Molar Volume (Vc) | 432 cm3/mol |
| Electrical Properties | Metric |
| Relative Permittivity (εr) | 1.921 |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.3855 |
| Hazardous Data | Metric |
| Flash Point | -4 °C |
| Autoignition Temperature | 204 °C |
| Lower Flammability Limit | 1.05% |
| Upper Flammability Limit | 6.7% |
| NFPA Rating (Health) | 1 |
| NFPA Rating (Fire) | 3 |
Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)
Related Pages
References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) Yaws, Carl L. The Yaws Handbook of Physical Properties for Hydrocarbons and Chemicals. Netherlands: Elsevier Science, 2015. 4) Fire Protection Guide to Hazardous Materials, 14th Edition. United States: National Fire Protection Association, 2010.