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calcium hypochlorite

 
Dictionary: calcium hypochlorite

n.
A white crystalline solid, Ca(OCl)2·4H2O, used as a bactericide, fungicide, and bleaching agent.


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Medical Dictionary: calcium hypochlorite
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n.

A white crystalline solid used as a bactericide, fungicide, and bleaching agent.

WordNet: calcium hypochlorite
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Note: click on a word meaning below to see its connections and related words.

The noun has one meaning:

Meaning #1: any hypochlorite of calcium; used as a bleaching agent


Wikipedia: Calcium hypochlorite
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Calcium hypochlorite
Other names Hypochlorous acid, calcium salt
Bleaching powder
Identifiers
CAS number 7778-54-3 Yes check.svgY
EC number 231-908-7
UN number 1748
RTECS number NH3485000
SMILES
InChI
InChI key ZKQDCIXGCQPQNV-UHFFFAOYAV
ChemSpider ID 22912
Properties
Molecular formula Ca(ClO)2
Molar mass 142.985 g/mol
Appearance white/gray powder
Density 2.35 g/cm3 (20 °C)
Melting point

100°C

Boiling point

175°C, decomposes

Solubility in water 21 g/100 ml, reacts
Solubility reacts in alcohol
Hazards
MSDS ICSC 0638
EU Index 017-012-00-7
EU classification Oxidant (O)
Corrosive (C)
Harmful (Xn)
Dangerous for the environment (N)
R-phrases R8, R22, R31, R34, R50
S-phrases (S1/2), S26, S36/37/39, S45, S61
NFPA 704
NFPA 704.svg
0
3
1
OX
Flash point Non-flammable
LD50 850 mg/kg (oral, rat)
Related compounds
Other anions Calcium chloride
Other cations Sodium hypochlorite
 Yes check.svgY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Calcium hypochlorite is a chemical compound with formula Ca(ClO)2. It is widely used for water treatment and as a bleaching agent (bleaching powder). This chemical is considered to be relatively stable and has greater available chlorine than sodium hypochlorite (liquid bleach).

Contents

Preparation

It is manufactured using the calcium process or the sodium process.

Calcium Process

2 Ca(OH)2 + 2 Cl2 → Ca(ClO)2 + CaCl2 + 2 H2O

Sodium Process

2 Ca(OH)2 + 3 Cl2 + 2 NaOH → Ca(ClO)2 + CaCl2 + 2 H2O + 2 NaCl

Bleaching powder is actually a mixture of calcium hypochlorite Ca(ClO)2 and the basic chloride CaCl2, Ca(OH)2, H2O with some slaked lime, Ca(OH)2.

Properties

It is a yellow white solid which has a strong smell of chlorine. Calcium hypochlorite is not highly soluble in water. For that reason it should preferably be used in soft to medium-hard water. There are two types of calcium hypochlorite - a dry form and a hydrated form. The hydrated form is safer to handle.

Calcium hypochlorite reacts with carbon dioxide to form calcium carbonate and release chlorine:

2Ca(ClO)2 + 2CO2 → 2CaCO3 + 2Cl2 + O2

Calcium hypochlorite reacts with hydrochloric acid to form calcium chloride:

Ca(ClO)2 + 4 HCl → CaCl2 + 2 H2O + 2 Cl2

Extreme care should be used in handling this product. Always keep in a cool dry place away from any organic material. When mixing it with water, it is safest to add the calcium hypochlorite to water. This material has been known to undergo self heating and rapid decomposition accompanied by the release of toxic chlorine gas.

Uses

Calcium hypochlorite is used for the disinfection of drinking water or swimming pool water. For use in outdoor swimming pools, calcium hypochlorite can be used as a sanitizer in combination with a cyanuric acid stabilizer. The stabilizer will reduce the loss of chlorine because of UV radiation. Calcium does make the water 'hard' and tends to clog up some filters. However, some types of calcium hypochlorite do contain anti-scaling agents in order to prevent clogging up of pipes/filters. This grade of calcium hypochlorite can also be used in hard waters. The main advantage of calcium hypochlorite is that it is unstabilized unlike chlorinated isocyanurates such as sodium dichloroisocyanurate or trichloroisocyanuric acid. Latter products do contain cyanuric acid. If the level of cyanuric acid becomes too high, it will influence the performance of the chlorine. Pools running on chlorinated isocyanurates should maintain a free chlorine level between 2 and 5 ppm (mg/L), whereas pools running on calcium hypochlorite should have a chlorine level of 1-2 ppm (mg/L).

Calcium hypochlorite (known as 'bleaching powder') is also used for bleaching cotton and linen and is used in the manufacture of chloroform.

Other uses are: 1. As bathroom cleaner 2. Clean secondhand items 3. Glow to glass dish ware 4. Household disinfectant spray 5. Remove moss and alga 6. Sanitize garden tools 7. Kill weeds in walkways 8. Preserve the cut flowers fresh 9. Clean lawn furniture

References

http://chemicalland21.com/industrialchem/inorganic/CALCIUM%20HYPOCHLORITE.htm

http://www.clean-pool-and-spa.com/swimming-pool-chlorine.html




 
 

 

Copyrights:

Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.  Read more
Medical Dictionary. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company Read more
WordNet. WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved.  Read more
Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Calcium hypochlorite" Read more