Chemistry:Potassium hypochlorite

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Potassium hypochlorite
Potassium hypochlorite
Potassium-3D.png
Hypochlorite-3D-vdW.png
Identifiers
3D model (JSmol)
ChemSpider
EC Number
  • 231-909-2
UNII
UN number 1791
Properties
KClO
Molar mass 90.55 g/mol
Appearance light grey liquid
Odor Chlorine-like
Density 1.160 g/cm3
Melting point −2 °C (28 °F; 271 K)
Boiling point 102 °C (216 °F; 375 K) (decomposes)
25%
Pharmacology
1=ATC code }} D08 (WHO)
Hazards
Safety data sheet MSDS
GHS pictograms GHS07: HarmfulGHS09: Environmental hazard
GHS Signal word Warning
H336, H411
P261, P271, P273, P304+340, P312, P391, P403+233, P405, P501
Related compounds
Other anions
Potassium chloride
Potassium chlorite
Potassium chlorate
Potassium perchlorate
Other cations
Sodium hypochlorite
Lithium hypochlorite
Calcium hypochlorite
Related compounds
Hypochlorous acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Potassium hypochlorite (chemical formula KClO) is the potassium salt of hypochlorous acid. It is used in variable concentrations, often diluted in water solution. It has a light grey color and a strong chlorine smell. It can be used as a disinfectant.

Preparation

Potassium hypochlorite is produced by the disproportionation reaction of chlorine with a solution of potassium hydroxide:[1]

Cl2 + 2 KOH → KCl + KClO + H2O

This is the traditional method, first used by Claude Louis Berthollet in 1789.[2]

Another production method is electrolysis of potassium chloride solution. With both methods, the reaction mixture must be kept cold to prevent formation of potassium chlorate.

Uses

Potassium hypochlorite is used for sanitizing surfaces as well as disinfecting drinking water. Because its degradation leaves behind potassium chloride rather than sodium chloride, its use has been promoted in agriculture, where addition of potassium to soil is desired.[3]

History

Potassium hypochlorite was first produced in 1789 by Claude Louis Berthollet in his laboratory located in Javel in Paris, France, by passing chlorine gas through a solution of potash lye. The resulting liquid, known as "Eau de Javel" ("Javel water"), was a weak solution of potassium hypochlorite. Due to production difficulties, the product was then modified using sodium instead of potassium, giving rise to sodium hypochlorite, widely used today as a disinfectant.

Safety and toxicology

Like sodium hypochlorite, potassium hypochlorite is an irritant. It can cause severe damage on contact with the skin, eyes, and mucous membranes.[4] Inhalation of a mist of KClO can cause bronchial irritation, difficulty breathing, and in severe cases pulmonary edema. Ingestion of strong concentrations can be lethal.[5]

Potassium hypochlorite is not considered a fire or explosive hazard by itself.[5] However, it can react explosively with numerous chemicals, including urea, ammonium salts, methanol, acetylene, and many organic compounds. Heating and acidification can produce toxic chlorine gas.[6]

References

  1. Uri Zoller, Paul Sosis (20 November 2008). Handbook of Detergents, Part F: Production. CRC Press. p. 452. ISBN 9781420014655. https://books.google.com/books?id=dXn3aB1DKk4C&pg=PA452. Retrieved 4 May 2016. 
  2. Helmut Vogt; Jan Balej; John E. Bennett; Peter Wintzer; Saeed Akhbar Sheikh; Patrizio Gallone (2007), "Chlorine Oxides and Chlorine Oxygen Acids", Ullmann's Encyclopedia of Industrial Chemistry (7th ed.), Wiley, p. 2 
  3. "Enviro Klor: 12.5% POTASSIUM HYPOCHLORITE BLEACH ALTERNATIVE". http://www.envirotech.com/pdf/EnviroKlor.pdf. 
  4. , Environmental Protection Agency.2 March 2011.
  5. 5.0 5.1 "Material Safety Data Sheet: Potassium Hypochlorite". http://www.kasteelchemicals.com/tinymce/filemanager/files/pot_hypo.pdf. 
  6. "Potassium Hypochlorite". http://www.chemicalbook.com/ChemicalProductProperty_EN_CB8332697.htm.