Properties of Carbonyl Sulfide (COS)
Carbonyl sulfide (COS) is a chemical compound composed of one carbon atom, one oxygen atom, and one sulfur atom. It is a colorless, flammable gas with an unpleasant odor that can be found in small quantities in Earth’s atmosphere.
The following table provides a comprehensive list of carbonyl sulfide 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 | 60.076 g/mol |
| Density (0°C) | 2.54 kg/m3 |
| Dynamic Viscosity (25°C) | 11.3 µPa·s |
| Thermal Properties | Metric |
| Melting Point | -138.8 °C |
| Boiling Point | -50.2 °C |
| Thermal Conductivity (25°C) | 0.014 W/m·K |
| Specific Heat Capacity (Cp) | 690 J/kg·K |
| Critical Constants | Metric |
| Critical Temperature (Tc) | 101.8 °C |
| Critical Pressure (Pc) | 5.87 MPa |
| Critical Density (ρc) | 440 kg/m3 |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.00147 |
| Hazardous Data | Metric |
| 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.