|Calcium hypochlorite or Calcium oxychloride|
|Jmol-3D images||Image 1|
|Molar mass||142.98 g/mol|
|Density||2.35 g/cm3 (20 °C)|
|Melting point||100 °C (212 °F; 373 K)|
|Boiling point||175 °C (347 °F; 448 K) decomposes|
|Solubility in water||21 g/100 mL, reacts|
|Solubility||reacts in alcohol|
|EU classification||Oxidant (O)
Dangerous for the environment (N)
|R-phrases||R8, R22, R31, R34, R50|
|S-phrases||(S1/2), S26, S36/37/39, S45, S61|
|LD50||850 mg/kg (oral, rat)|
|Other anions||Calcium chloride|
|Other cations||Sodium hypochlorite|
|Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)|
|(what is: / ?)|
Calcium hypochlorite also known as chlorine powder or bleach powder is a chemical compound with formula Ca(ClO)2. It is widely used for water treatment and as a bleaching agent. This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochlorite (liquid bleach).
Calcium hypochlorite is used for the disinfection of drinking water or swimming pool water. Generally it is sold as 68% calcium hypochlorite combined with calcium chloride and other salts. It is used as a sanitizer in outdoor swimming pools in combination with a cyanuric acid stabilizer, which reduces the loss of chlorine due to ultraviolet radiation. The calcium content hardens the water and tends to clog up some filters; hence, some products containing calcium hypochlorite also contain anti-scaling agents.
Calcium hypochlorite is an ingredient in bleaching powder, used for bleaching cotton and linen. It is used in bathroom cleaners, household disinfectant sprays, moss and algae removers, and weedkillers.
In addition, calcium hypochlorite may be used to manufacture chloroform.
Calcium hypochlorite is best kept in a cool dry place away from any organic material. It is known to undergo self heating and rapid decomposition accompanied by the release of toxic chlorine gas.
- 2 Cl
2 + 2 Ca(OH)
2 → Ca(OCl)
2 + CaCl
2 + 2 H
Bleaching powder was made by passing chlorine gas with slightly moist slaked lime. This formed a white powder. The exact constitution depends on the maufacturing conditions. It is not a simple mixture of calcium hypochlorite, calcium chloride and calcium hydroxide. It is believed to be a variable mixture consisting pricipally of calcium hypochlorite Ca(OCl)2 , dibasic calcium hypochlorite, Ca3(OCl)2(OH)4 and dibasic calcium chloride, Ca3Cl2(OH)4.
Calcium hypochlorite is a yellow white solid which has a strong smell of chlorine. It is not highly soluble in water and is more preferably used in soft to medium-hard water. It has two forms: dry and hydrated. The hydrated form is safer to handle.
2 + CO
2 → CaCO
3 + Cl
A calcium hypochlorite solution is basic. This is due to the hydrolysis performed by the hypochlorite ion, as hypochlorous acid is weak, but calcium hydroxide is a strong base. As a result, the hypochlorite ion is a strong conjugate base, and the calcium ion is a weak conjugate acid:
+ H2O → HClO + OH−
- Ca(OCl)2 + 4 HCl → CaCl2 + 2 H2O + 2 Cl2
- Gerald F. Connell. "KEY OPERATING STRATEGIES FOR CHLORINE DISINFECTION OPERATING SYSTEMS". Retrieved 19 October 2014.
- Chemical Products Synopsis: Calcium Hypochlorite (Technical report). Asbuiy Park, NJ: Mannsvile Chemical Products. 1987.
- W.L Smith, Inorganic bleaches, Production of Hypochlorite in Handbook of Detergents,Part F, (2009) Ed. U Zoller and Paul Sosis, CRCPress, ISBN 978-0-8247-0349-3