Properties of Water (H2O)
Water is a colorless, odorless, and tasteless chemical substance composed of two hydrogen atoms bonded to one oxygen atom, chemically represented as H2O. It is essential for life and exists in three common states: solid (ice), liquid (water), and gas (water vapor).
The following table provides a comprehensive list of water 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 | 18.015 g/mol |
| Density | 998 kg/m3 |
| Dynamic Viscosity (25°C) | 0.89 mPa·s |
| Surface Tension | 72.75 mN/m |
| Thermal Properties | Metric |
| Melting Point | 0 °C |
| Boiling Point | 100 °C |
| Thermal Conductivity (25°C) | 0.6062 W/m·K |
| Specific Heat Capacity (Cp) | 4184 J/kg·K |
| Coefficient of Thermal Expansion (αV) | 2.06×10-4 1/°C |
| Vapor Pressure (25°C) | 3.17 kPa |
| Critical Constants | Metric |
| Critical Temperature (Tc) | 374 °C |
| Critical Pressure (Pc) | 22.05 MPa |
| Critical Molar Volume (Vc) | 56 cm3/mol |
| Electrical Properties | Metric |
| Relative Permittivity (εr) | 80.1 |
| Optical Properties | Metric |
| Refractive Index (589 nm) | 1.333 |
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.