Properties of Carbon Monoxide (CO)
Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that consists of one carbon atom and one oxygen atom. It is produced when carbon-containing fuels, such as gasoline, natural gas, or wood, do not burn completely due to a lack of oxygen. Carbon monoxide is toxic and can be harmful to humans and animals when inhaled.
The following table provides a comprehensive list of carbon monoxide 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 | 28.01 g/mol |
| Density (25°C) | 1.145 kg/m3 |
| Dynamic Viscosity (25°C) | 17.8 µPa·s |
| Speed of Sound in Gas (0°C) | 337 m/s |
| Thermal Properties | Metric |
| Melting Point | -205 °C |
| Boiling Point | -191.5 °C |
| Thermal Conductivity (25°C) | 0.025 W/m·K |
| Specific Heat Capacity (Cp) | 1040 J/kg·K |
| Critical Constants | Metric |
| Critical Temperature (Tc) | -140.2 °C |
| Critical Pressure (Pc) | 3.49 MPa |
| Critical Density (ρc) | 301 kg/m3 |
| Electrical Properties | Metric |
| Relative Permittivity (εr) | 1.00065 |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.000482 |
| Hazardous Data | Metric |
| Autoignition Temperature | 700 °C |
| Lower Flammability Limit | 12% |
| Upper Flammability Limit | 75% |
| NFPA Rating (Health) | 3 |
| 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.