water
H2O
Water has the molecular formula H2O and a molar mass of 18.02 g/mol, a melting point of 0 °C and a boiling point of 100 °C.
Properties
| Molecular formula | H2O |
|---|---|
| Molar mass | 18.015 g/mol |
| Exact (monoisotopic) mass | 18.01056 g/mol |
| Melting point | 0 °C |
| Boiling point | 99.97 °C |
| Density | 0.9653 g/cm³ |
| logP (octanol–water) | -0.5 |
| Topological polar surface area | 1 Ų |
| Hydrogen-bond donors / acceptors | 1 / 1 |
| Heavy atoms | 1 |
| InChIKey | XLYOFNOQVPJJNP-UHFFFAOYSA-N |
| IUPAC name | oxidane |
Elemental composition
3 atoms across 2 elements, by mass.
| Element | Atoms | Percent by mass |
|---|---|---|
| Oxygen (O) | 1 | 88.81% |
| Hydrogen (H) | 2 | 11.19% |
Calculate with water
- Molar mass and percent composition
- Convert between moles and grams
- Make up a solution of known molarity
- Gas density at any temperature and pressure
Related compounds
Molar mass and elemental composition are computed from IUPAC 2021 conventional atomic weights. Formula, exact mass and the computed descriptors come from PubChem, which is US government work and in the public domain. Melting point, boiling point and density come from Wikidata under CC0. Properties with no figure shown are absent from those sources rather than zero.