Calcium oxide
chemical compound
Calcium oxide is a chemical compound of calcium and oxygen. Its chemical formula is CaO. It is known as quicklime. It is made in a lime kiln. It releases heat when dissolved in water and changes into calcium hydroxide. It is a white powder.
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IUPAC name
Calcium oxide
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Other names
Quicklime, burnt lime, unslaked lime, pebble lime, calcia
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Identifiers | |
3D model (JSmol)
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ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard | 100.013.763 |
E number | E529 (acidity regulators, ...) |
Gmelin Reference | 485425 |
PubChem CID
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RTECS number |
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UNII | |
UN number | 1910 |
CompTox Dashboard (EPA)
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Properties | |
CaO | |
Molar mass | 56.0774 g/mol |
Appearance | White to pale yellow/brown powder |
Odor | Odorless |
Density | 3.34 g/cm3[1] |
Melting point | 2,613 °C (4,735 °F; 2,886 K)[1] |
Boiling point | 2,850 °C (5,160 °F; 3,120 K) (100 hPa)[2] |
Reacts to form calcium hydroxide | |
Solubility in Methanol | Insoluble (also in diethyl ether, octanol) |
Acidity (pKa) | 12.8 |
−15.0×10−6 cm3/mol | |
Structure | |
Cubic, cF8 | |
Thermochemistry | |
Std enthalpy of formation ΔfH |
−635 kJ·mol−1[3] |
Standard molar entropy S |
40 J·mol−1·K−1[3] |
Pharmacology | |
QP53AX18 (WHO) | |
Hazards | |
NFPA 704 |
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Flash point | Non-flammable |
U.S. Permissible exposure limit (PEL) |
TWA 5 mg/m3[4] |
Related compounds | |
Other anions | Calcium sulfide Calcium hydroxide |
Other cations | Beryllium oxide Magnesium oxide Strontium oxide Barium oxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Infobox references | |
It is also a base. It reacts with acids to make calcium salts. Quicklime is an important ingredient of cement.
Related pagesEdit
ReferencesEdit
- ↑ 1.0 1.1 Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.55. ISBN 1439855110.
- ↑ Calciumoxid Archived 2013-12-30 at the Wayback Machine. GESTIS database
- ↑ 3.0 3.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A21. ISBN 978-0-618-94690-7.
- ↑ NIOSH Pocket Guide to Chemical Hazards. "#0093". National Institute for Occupational Safety and Health (NIOSH).