Calcium oxide
CaO56.08 g/mol Calculated
Also called quicklime, caustic lime, calx and calcium monoxide.
Quicklime, made by roasting limestone. It gets hot when it meets water, which is how self-heating cans work and why lime mortar sets.
Sources and notes
- The introductionfrom sourceMoleculeFinder curated
- Other namesfrom sourceWikidataIts English label and aliases on Wikidata.
- Formula and weightcomputedPubChem
- 2D drawingcomputedPubChem structure, drawn by RDKit
Properties and sources
Calculated by PubChem
- Molecular formula
- CaO
- Molecular weight
- 56.08 g/mol
- Polar surface areatopological
- 17.1 Ų
- H-bond donors
- 0
- H-bond acceptors
- 1
- Rotatable bonds
- 0
- Complexity
- 2
Reported Hazard label (GHS), ECHA, Safe Work Australia via PubChem
Danger Corrosive pictogram (GHS05) and Irritant pictogram (GHS07); hazard statements H302, H314, H315, H318, H335
Groups it belongs to
- Category
- Everyday chemistry
- Family
- Inorganic compounds
- Elements
- Calcium
- Hazard classes
- Corrosive, Irritant, GHS Danger
- Size
- Under 100 g/mol
SMILES
O=[Ca]PubChem CID 14778 · Wikidata Q185006 · InChIKey ODINCKMPIJJUCX-UHFFFAOYSA-N · Data refreshed
Questions
- What is Calcium oxide?
- Quicklime, made by roasting limestone. It gets hot when it meets water, which is how self-heating cans work and why lime mortar sets.
- How toxic is Calcium oxide?
- Its GHS hazard label carries the signal word Danger and the hazard pictograms Corrosive and Irritant. from source
- What kind of molecule is Calcium oxide?
- Calcium oxide has the formula CaO and a molecular weight of 56.08 g/mol. MoleculeFinder files it under inorganic compounds, in the everyday chemistry group. from sourcefrom sourcefrom sourcefrom source
- What else is Calcium oxide called?
- Calcium oxide is also called caustic lime, quicklime, calx and calcium monoxide. from source
Sources and notes
- Calculated valuescomputedPubChemComputed from the structure, so no laboratory conditions apply; complexity is PubChem's own structural score.
- Hazard labelfrom sourceECHA, Safe Work Australia via PubChemThe label combines these classifications.
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- Safe Work Australiafrom sourceAttributionSource: Safe Work Australia, Hazardous Chemical Information System, © Commonwealth of Australia, CC BY 4.0.
- Data refreshedfrom sourceMoleculeFinder2026-11-09