File:Calcium-oxide-3D-vdW.png · Wikimedia Commons · See Wikimedia Commons
calcium oxide
Sign in to saveAlso known as caustic lime, quicklime, calx, calcium monoxide, limestone, burned lime, burnt lime, lime
chemical compound
OverviewAI-generated
Calcium oxide, also referred to as oxocalcium, is a chemical compound with the formula CaO. It has a density of 3.34 and a mass of 55.958. The substance exhibits a melting point of 4662 and a boiling point of 5162. Its standard enthalpy of formation is -635.09, while its ionization energy is 6.90. The compound has a vapor pressure of 0 and a charge of 0.
In terms of molecular properties, calcium oxide has a topological polar surface area of 17.1. It contains 0 hydrogen bond donors and 1 hydrogen bond acceptor. Safety guidelines indicate a time-weighted average exposure limit of 5 and an immediately dangerous to life or health level of 25. The compound is associated with a PubMed query count of 10410 and is referenced by 976 other encyclopedia articles.
Synthesized by Vinony from 26 facts across 4 sources: Wikidata, PubChem, PubMed, Vinony graph. Generated from structured data (not the Wikipedia text) and checked against those facts — may still contain errors.
Chemical data
- Formula
- CaO
- Molecular weight
- 56.08 g/mol
- IUPAC name
- oxocalcium
- SMILES
- O=[Ca]
- InChIKey
- ODINCKMPIJJUCX-UHFFFAOYSA-N
- Polar surface area
- 17.1 Ų
- H-bond donors
- 0
- H-bond acceptors
- 1
- Formal charge
- 0
via PubChem
Research
10,410 papers- Effects of Calcium-Oxide-Modified Biochar on the Anaerobic Digestion of Vacuum Blackwater.ReviewMolecules (Basel, Switzerland) · 2025Chiang PF, Zhang TL, Giwa AS et al.DOI: 10.3390/molecules30020215
- Advances in the fabrication, modification, and performance of biochar, red mud, calcium oxide, and bentonite catalysts in waste-to-fuel conversion.ReviewEnvironmental research · 2023Nganda A, Srivastava P, Lamba BY et al.DOI: 10.1016/j.envres.2023.116284
- Systematic review of antibacterial potential in calcium oxide and silicon oxide nanoparticles for clinical and environmental infection control.Journal of applied biomedicine · 2025Algadi H, Abdelfatah Alhoot M, Yaaqoob LADOI: 10.32725/jab.2025.001
- Calcium oxide enhances the anaerobic co-digestion of excess sludge and plant waste: performance and mechanism.Water science and technology : a journal of the International Association on Water Pollution Research · 2024Wang Y, Wang K, Zhou X et al.DOI: 10.2166/wst.2024.268
- Calcium oxide adsorption of gas phase PCDD/Fs and its impact on the adsorption properties of activated carbon.Environmental pollution (Barking, Essex : 1987) · 2024Lai J, Wang P, Qi H et al.DOI: 10.1016/j.envpol.2024.124750
- Recent Progress in the Development of Disinfectants from Scallop Shell-Derived Calcium Oxide for Clinical and Daily Use.ReviewBiocontrol science · 2021Hata Y, Ishihara M, Hiruma S et al.DOI: 10.4265/bio.26.129
- Calcium oxide nanoparticles ameliorate cadmium toxicity in alfalfa seedlings by depriving its bioaccumulation, enhancing photosystem II functionality and antioxidant gene expression.The Science of the total environment · 2024Hussan MU, Hussain S, Adeel M et al.DOI: 10.1016/j.scitotenv.2024.176797
- Calcium oxide nanoparticles mitigate lead stress in Abelmoschus esculentus though improving the key antioxidative enzymes, nutritional content and modulation of stress markers.Plant physiology and biochemistry : PPB · 2024Raza HZ, Shah AA, Noreen Z et al.DOI: 10.1016/j.plaphy.2023.108171
via PubMed
~8 min read
Encyclopedic overview
Calcium oxide (formula: CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature. The broadly used term lime connotes calcium-containing inorganic compounds, in which carbonates, oxides, and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate. By contrast, quicklime specifically applies to the single compound calcium oxide. Calcium oxide that survives processing without reacting in building products, such as cement, is called free lime.
Quicklime is relatively inexpensive. Both it and the chemical derivative calcium hydroxide (of which quicklime is the base anhydride) are important commodity chemicals.
Excerpted from Wikipedia’s “calcium oxide” article, available under the CC BY-SA 4.0 licence.
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