Calcium oxide
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Calcium oxide (CaO), commonly kent as quicklime or burnt lime, is a widely uised chemical compoond. It is a white, caustic, alkaline crystalline solit at ruim temperatur. The braid uised term "lime" connotes calcium-containin inorganic materials, that include carbonates, oxides an hydroxides o calcium, silicon, magnesium, aluminium, an airn predominate, lik limestone. Bi contrast, "quicklime" specifically applies tae a single chemical compoond.
Quick Facts Names, Identifiers ...
Names | |
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IUPAC name
Calcium oxide | |
Ither names
Quicklime, burnt lime, unslaked lime | |
Identifiers | |
CAS Nummer |
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3D model (JSmol) |
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ChemSpider | |
PubChem CID |
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RTECS nummer | EW3100000 |
UNII | |
UN nummer | 1910 |
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SMILES
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Properties | |
CaO | |
Molar mass | 56.0774 g/mol |
Appearance | White tae fauch yellae/broun pouder |
Odour | odorless |
Density | 3.34 g/cm3[1] |
Meltin pynt | 2613 °C, 2886 K, 4735 °F[1] |
Bylin pynt | 2850 °C, 3123 K (100 hPa)[2] |
Solubility in watter |
1.19 g/L (25 °C), 0.57 g/L (100 °C), exothermic reaction[3] |
Solubility in acids | soluble (an aa in glycerol, succar solution) |
Solubility in methanol | insoluble (an aa in diethyl ether, n-octanol) |
Acidity (pKa) | 12.8 |
Thermochemistry | |
Staundart molar entropy S |
40 J·mol−1·K−1[4] |
Std enthalpy o formation ΔfH |
−635 kJ·mol−1[4] |
Hazards | |
NFPA 704 |
0
3
2 |
Flash pynt | Non-flammable |
Relatit compoonds | |
Ither anions |
Calcium sulfide Calcium hydroxide |
Ither cations |
Beryllium oxide Magnesium oxide Strontium oxide Barium oxide |
Except whaur itherwise notit, data are gien for materials in thair staundart state (at 25 °C [77 °F], 100 kPa). | |
Infobox references | |
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Quicklime is relatively inexpensive. Baith it an a chemical derivative (calcium hydroxide) is important commodity chemicals.