Calcium oxide

Calcium oxide
Names
	IUPAC name Calcium oxide
	Other names Quicklime, burnt lime, unslaked lime, pebble lime, calcia
Identifiers
CAS Number	1305-78-8;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:31344;
ChEMBL	ChEMBL2104397;
ChemSpider	14095;
ECHA InfoCard	100.013.763
E number	E529 (acidity regulators, ...)
Gmelin Reference	485425
PubChem CID	14778;
RTECS number	EW3100000;
UNII	C7X2M0VVNH;
UN number	1910
CompTox Dashboard (EPA)	DTXSID5029631 ;
	SMILES [Ca]=O;
Properties
Chemical formula	CaO
Molar mass	56.0774 g/mol
Appearance	White to pale yellow/brown powder
Odor	Odorless
Density	3.34 g/cm3
Melting point	2,613 °C (4,735 °F; 2,886 K)
Boiling point	2,850 °C (5,160 °F; 3,120 K) (100 hPa)
Solubility in water	Reacts to form calcium hydroxide
Solubility in Methanol	Insoluble (also in diethyl ether, octanol)
Acidity (pKa)	12.8
Magnetic susceptibility (χ)	−15.0×10−6 cm3/mol
Structure
Crystal structure	Cubic, cF8
Thermochemistry
Std enthalpy of; formation ΔfHo298	−635 kJ·mol−1
Standard molar; entropy So298	40 J·mol−1·K−1
Pharmacology
ATCvet code	QP53AX18 (WHO)
Hazards
NFPA 704	0 3 2
Flash point	Non-flammable
U.S. Permissible; exposure limit (PEL)	TWA 5 mg/m3
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

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.

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).

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[crc-1] 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.

[r1-2] Calciumoxid Archived 2013-12-30 at the Wayback Machine. GESTIS database

[b1-3] 3.0 ^3.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A21. ISBN 978-0-618-94690-7.

[PGCH-4] NIOSH Pocket Guide to Chemical Hazards. "#0093". National Institute for Occupational Safety and Health (NIOSH).

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