|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 commonly used to sanitize public swimming pools and disinfect drinking water. Generally the commercial substance is sold with a purity of a 68% (with other additives and contaminants varying based upon the product's intended purpose). For instance as a swimming pool chemical it is often mixed with cyanuric acid stabilizers and anti-scaling agents (in order to reduce the loss of chlorine from ultraviolet radiation and to prevent calcium hardening). Calcium hypochlorite is also used in kitchens to disinfect surfaces and equipment. Other common uses include bathroom cleansers, household disinfectant sprays, algaecides, herbicides, and laundry detergents.
Calcium hypochlorite is a general oxidizing agent and therefore has many uses in organic chemistry. For instance the compound is used to cleave glycols, α-hydroxy carboxylic acids and keto acids to yield fragmented aldehydes or carboxylic acids. Calcium hypochlorite is also used in the haloform reaction 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.
- Nwaukwa, Stephen; Keehn, Philip (1982). "The oxidation of aldehydes to acids with calcium hypochlorite [Ca(OCl)2]". Tetrahedron Letters 23 (31): 3131–3134. doi:10.1016/S0040-4039(00)88577-9.
- Nwaukwa, Stephen; Keehn, Philip (1982). "Oxidative cleavage of α-diols, α-diones, α-hydroxy-ketones and α-hydroxy- and α-keto acids with calcium hypochlorite [Ca(OCl)2]". Tetrahedron Letters 23 (31): 3135–3138. doi:10.1016/S0040-4039(00)88578-0.
- Cohen, Julius (1900). Practical Organic Chemistry for Advanced Students. Newyork: Macmillan & Co. p. 63.
- 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