Properties of Methane (CH4)
Methane is a chemical compound with the molecular formula CH4. It is the simplest hydrocarbon, consisting of one carbon atom bonded to four hydrogen atoms. Methane is a colorless, odorless gas and is the primary component of natural gas. It is a potent greenhouse gas and is also used as a fuel for heating and electricity generation.
The following table provides a comprehensive list of methane 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 | 16.043 g/mol |
| Density (25°C) | 0.657 kg/m3 |
| Dynamic Viscosity (25°C) | 11.1 µPa·s |
| Speed of Sound in Gas (27°C) | 450 m/s |
| Thermal Properties | Metric |
| Melting Point | -182.5 °C |
| Boiling Point | -161.6 °C |
| Thermal Conductivity (25°C) | 0.0344 W/m·K |
| Specific Heat Capacity (Cp) | 2225 J/kg·K |
| Critical Constants | Metric |
| Critical Temperature (Tc) | -82.6 °C |
| Critical Pressure (Pc) | 4.6 MPa |
| Critical Density (ρc) | 162 kg/m3 |
| Electrical Properties | Metric |
| Relative Permittivity (εr) | 1.000944 |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.000444 |
| Hazardous Data | Metric |
| Autoignition Temperature | 540 °C |
| Lower Flammability Limit | 5% |
| Upper Flammability Limit | 15% |
| NFPA Rating (Health) | 2 |
| NFPA Rating (Fire) | 4 |
| NFPA Rating (Reactivity) | 0 |
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.