Adding water to quicklime is strongly exothermic: CaO + H₂O → Ca(OH)₂ + heat.
How it is made
Heat limestone: CaCO₃ → CaO + CO₂
Uses
Making slaked lime, cement and glass, drying gases.
What it is made of
| Element | Atoms | % by mass |
|---|---|---|
| Ca | 1 | 71.5% |
| O | 1 | 28.5% |
Molar mass = 56.08 g/mol.
Common names and formulas
| Common name | Formula |
|---|---|
| Baking sodasodium hydrogen carbonate (sodium bicarbonate) | NaHCO3 |
| Washing sodasodium carbonate decahydrate | Na2CO3·10H2O |
| Soda ashanhydrous sodium carbonate | Na2CO3 |
| Bleaching powdercalcium oxychloride (calcium hypochlorite chloride) | CaOCl2 |
| Plaster of Pariscalcium sulphate hemihydrate | CaSO4·½H2O |
| Gypsumcalcium sulphate dihydrate | CaSO4·2H2O |
| Quicklimecalcium oxide | CaO |
| Slaked limecalcium hydroxide | Ca(OH)2 |
| Limestone (chalk, marble)calcium carbonate | CaCO3 |
| Common saltsodium chloride | NaCl |
| Caustic sodasodium hydroxide | NaOH |
| Caustic potashpotassium hydroxide | KOH |
| Blue vitriolcopper(II) sulphate pentahydrate | CuSO4·5H2O |
| Green vitrioliron(II) sulphate heptahydrate | FeSO4·7H2O |
| White vitriolzinc sulphate heptahydrate | ZnSO4·7H2O |
| Epsom saltmagnesium sulphate heptahydrate | MgSO4·7H2O |
| Glauber's saltsodium sulphate decahydrate | Na2SO4·10H2O |
| Potash alumpotassium aluminium sulphate dodecahydrate | K2SO4·Al2(SO4)3·24H2O |
| Boraxsodium tetraborate decahydrate | Na2B4O7·10H2O |
| Mohr's saltferrous ammonium sulphate hexahydrate | FeSO4·(NH4)2SO4·6H2O |
| Hyposodium thiosulphate pentahydrate | Na2S2O3·5H2O |
| Laughing gasnitrous oxide (dinitrogen monoxide) | N2O |
| Dry icesolid carbon dioxide | CO2 |
| Marsh gasmethane | CH4 |
| Muriatic acidhydrochloric acid | HCl |
| Oil of vitriolsulphuric acid | H2SO4 |
| Sal ammoniacammonium chloride | NH4Cl |
| Lunar causticsilver nitrate | AgNO3 |
| Chile saltpetresodium nitrate | NaNO3 |
| Saltpetre (Indian saltpetre)potassium nitrate | KNO3 |
| Calomelmercury(I) chloride | Hg2Cl2 |
| Corrosive sublimatemercury(II) chloride | HgCl2 |
| Philosopher's woolzinc oxide | ZnO |
| Red lead (sindhur)triplumbic tetroxide (lead(II,IV) oxide) | Pb3O4 |
| Liquid bleachsodium hypochlorite | NaOCl |
| Vinegarethanoic acid (acetic acid), 5–8% in water | CH3COOH |
| Table sugarsucrose | C12H22O11 |
| Spirit (grain alcohol)ethanol | C2H5OH |
| Wood spiritmethanol (methyl alcohol) | CH3OH |
| Chloroformtrichloromethane | CHCl3 |
| Carbamideurea | CO(NH2)2 |
Questions students ask
What is the chemical formula of quicklime?
CaO. Its chemical name is calcium oxide.
What is the chemical name of quicklime?
Calcium oxide, CaO.
What is the molar mass of quicklime?
56.08 g/mol (about 56 g/mol with exam atomic masses).
How is quicklime made?
Heat limestone: CaCO₃ → CaO + CO₂.
What are the uses of quicklime?
Making slaked lime, cement and glass, drying gases.