Properties of Pyridine (C5H5N)
Pyridine is a heterocyclic organic compound with a six-membered ring structure containing five carbon atoms and one nitrogen atom. It is a colorless, flammable liquid with a pungent odor and is often used as a basic solvent and reagent in various chemical reactions.
The following table provides a comprehensive list of pyridine 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 | 79.1 g/mol |
| Density | 982 kg/m3 |
| Dynamic Viscosity | 0.974 mPa·s |
| Thermal Properties | Metric |
| Melting Point | -41.6 °C |
| Boiling Point | 115.2 °C |
| Thermal Conductivity (25°C) | 0.166 W/m·K |
| Vapor Pressure | 2.09 kPa |
| Critical Constants | Metric |
| Critical Temperature (Tc) | 347 °C |
| Critical Pressure (Pc) | 5.63 MPa |
| Critical Molar Volume (Vc) | 248 cm3/mol |
| Electrical Properties | Metric |
| Relative Permittivity (εr) | 13.26 |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.5095 |
| Hazardous Data | Metric |
| Flash Point | 20 °C |
| Autoignition Temperature | 482 °C |
| Lower Flammability Limit | 1.8% |
| Upper Flammability Limit | 12.4% |
| NFPA Rating (Health) | 3 |
| NFPA Rating (Fire) | 3 |
| 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.