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calcium oxide
calcium oxide chemical compound, CaO, a colorless, cubic crystalline or white amorphous substance. It is also called lime, quicklime, or caustic lime, but commercial lime often contains impurities, e.g., silica, iron, alumina, and magnesia. It is prepared by heating calcium carbonate (e.g., limestone ) in a special lime kiln to about 500°C to 600°C, decomposing it into the oxide and carbon dioxide. Calcium oxide is widely used in industry, e.g., in making porcelain and glass; in purifying sugar; in preparing bleaching powder , calcium carbide, and calcium cyanamide; in water softeners; and in mortars and cements. In agriculture it is used for treating acidic soils ( liming ). It is incandescent when heated to high temperatures; the Drummond light, or limelight, provides a brilliant white light by heating a cylinder of lime with the flame of an oxyhydrogen torch. Calcium oxide is a basic anhydride, reacting with water to form calcium hydroxide ; during the reaction (slaking) much heat is given off and the solid nearly doubles its volume. |
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"calcium oxide." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "calcium oxide." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1E1-calciumo.html "calcium oxide." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-calciumo.html |
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calcium oxide
calcium oxide (quicklime) White solid (CaO) made by heating calcium carbonate (CaCO3) at high temperatures. It is used industrially to treat acidic soil and to make porcelain and glass, bleaching powder, caustic soda, mortar and cement. Calcium oxide reacts with water to form calcium hydroxide (Ca(OH)2).
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"calcium oxide." World Encyclopedia. 2005. Encyclopedia.com. 10 Feb. 2012 <http://www.encyclopedia.com>. "calcium oxide." World Encyclopedia. 2005. Encyclopedia.com. (February 10, 2012). http://www.encyclopedia.com/doc/1O142-calciumoxide.html "calcium oxide." World Encyclopedia. 2005. Retrieved February 10, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-calciumoxide.html |
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