Potassium bromate
| Potassium bromate | |
|---|---|
| IUPAC name | Potassium bromate |
| Other names | Potassium bromate(V) |
| Identifiers | |
| InChI | InChI=1/BrHO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 |
| InChIKey | OCATYIAKPYKMPG-REWHXWOFAM |
| Standard InChI | InChI=1S/BrHO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 |
| Standard InChIKey | OCATYIAKPYKMPG-UHFFFAOYSA-M |
| CAS number | [] |
| EC number | |
| ChemSpider | |
| Properties[1] | |
| Chemical formula | KBrO3 |
| Molar mass | 167.00 g mol−1 |
| Appearance | white crystalline solid |
| Density | 3.27 g cm−3 |
| Melting point |
327 °C decomp. |
| Solubility in water | 7.53 g/100 g (25 °C) 25.4 g/100 g (80 °C) |
| Hazards[2] | |
| Material safety data sheet (MSDS) | ICSC |
| GHS pictograms |   
|
| GHS signal word | DANGER |
| GHS hazard statements | H271, H301, H350 |
| GHS precautionary statements | P201, P202, P210, P220, P221, P264, P270, P280, P281, P283, P301+312, P302+352, P321, P330 |
| Related compounds | |
| Other anions | Potassium chlorate Potassium iodate |
| Other cations | Lithium bromate Sodium bromate Rubidium bromate Caesium bromate |
| Other compounds | Potassium bromide Potassium hypobromite Potassium bromite Potassium perbromate |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
Potassium bromate is the potassium salt of bromic acid. It is a food additive (INS 924a), especially used for preparing bromated flour.
Contents
Preparation
Potassium bromate is usually prepared by the electrolysis of potassium bromide solution at 65–70 °C, in the presence of dichromate and using anodes of lead dioxide or iron and cathodes of stainless steel or copper.[3] The potassium bromate can be crystallized by cooling the electrolyte, and any unoxidized bromide recycled.[1]
Potassium bromate can also be prepared by reacting bromine with potassium hydroxide solution at 50–90 °C.[4]
- 3 Br2 + 3 OH− ⇌ BrO−3 + 5 Br− + 3 H+
The disadvantage of this approach is that only one-sixth of the bromine is converted into bromate. However, bromide/bromate mixtures are useful in gold mining, and so this method finds some commercial use.[1] The mixture has also been proposed as a safe way of transporting bromine, as the equilibrium can be reversed by the addition of strong acid.[4]
Notes and references
Notes
References
- ↑ 1.0 1.1 1.2 Ukeles, S. D.; Freiberg, M. Bromine, Inorganic Compounds. In Kirk-Othmer Encyclopedia of Chemical Technology; John Wiley: New York, 2002. DOI: 10.1002/0471238961.021815131001031.
- ↑ Index no. 035-003-00-6 of Annex VI, Part 3, to Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006. OJEU L353, 31.12.2008, pp 1–1355 at p 429.
- ↑ Osuga, Takasi; Sugino, Kiichiro Electrolytic Production of Bromates. J. Electrochem. Soc. 1957, 104 (7), 448–51. DOI: 10.1149/1.2428623.
- ↑ 4.0 4.1 Prager, Aavi; Smilovitch, Shaul; Freiberg, Mira, et al. (Bromine Compounds Ltd.) Alkali and alkaline earth metal bromide and bromate solid mixtures and process for preparation thereof. IL Patent 84830, published 24 January 1995.
Further reading
- Potassium bromate. In Some Chemicals that Cause Tumours of the Kidney or Urinary Bladder in Rodents and Some Other Substances; IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 73; International Agency for Research on Cancer: Lyon, France, 1999; pp 481–96. ISBN 92-832-1273-8, <http://monographs.iarc.fr/ENG/Monographs/vol73/mono73-22.pdf>.
- Kim, Yoon J. (Research Resources Inc.) Potassium bromate replacer composition. US Patent 5510129, published 23 April 1996.
External links
 |
See also the corresponding article on Wikipedia. |
- FAO/WHO Joint Expert Committee on Food Additives (JECFA) evaluation (summary): Potassium bromate
- FAO/WHO Joint Expert Committee on Food Additives (JECFA) monograph: Potassium bromate (WHO Food Additives Series 30)
| Error creating thumbnail: Unable to save thumbnail to destination |
This page is currently licensed under the Creative Commons Attribution 3.0 Unported license and any later versions of that license. |
