Water Properties
Physical and thermodynamic properties of water — density, viscosity, specific heat, phase transitions.
Reference
Molecular
- Formula
- H₂O
- Molar mass
- 18.015 g/mol
- Bond angle
- 104.5°
- O–H bond length
- 0.9584 Å
Thermal
- Melting point (1 atm)
- 0.00 °C (273.15 K)
- Boiling point (1 atm)
- 99.974 °C (373.12 K)
- Triple point
- 0.01 °C @ 611.657 Pa
- Critical point
- 374 °C @ 22.064 MPa
- Heat capacity (liquid, 25 °C)
- 4181.3 J/(kg·K)
- Heat of fusion
- 334 kJ/kg
- Heat of vaporization
- 2257 kJ/kg (at 100 °C)
- Thermal conductivity
- 0.598 W/(m·K) at 20 °C
Density (liquid)
| Temperature | Density (kg/m³) |
|---|---|
| 0 °C | 999.84 |
| 4 °C | 999.97 (max) |
| 10 °C | 999.70 |
| 20 °C | 998.21 |
| 25 °C | 997.05 |
| 50 °C | 988.04 |
| 100 °C | 958.37 |
Viscosity
| Temperature | Dynamic (mPa·s) | Kinematic (mm²/s) |
|---|---|---|
| 0 °C | 1.793 | 1.793 |
| 20 °C | 1.002 | 1.004 |
| 40 °C | 0.653 | 0.658 |
| 80 °C | 0.355 | 0.365 |
Other
- Surface tension (20 °C)
- 72.8 mN/m
- Refractive index (589 nm)
- 1.333
- Dielectric constant (20 °C)
- 80.1
- Dissociation constant pKw
- 14.0 at 25 °C
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