Sodium bromate
| Sodium bromate | |
|---|---|
| IUPAC name | Sodium bromate |
| Other names | Sodium bromate(V) |
| Identifiers | |
| InChI | InChI=1/BrHO3.Na/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 |
| InChIKey | XUXNAKZDHHEHPC-REWHXWOFAY |
| Standard InChI | InChI=1S/BrHO3.Na/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 |
| Standard InChIKey | XUXNAKZDHHEHPC-UHFFFAOYSA-M |
| CAS number | [] |
| EC number | |
| ChemSpider | |
| Properties[1] | |
| Chemical formula | NaBrO3 |
| Molar mass | 150.89 g mol−1 |
| Appearance | white crystalline solid |
| Density | 3.34 g cm−3 |
| Melting point |
381 °C decomp. |
| Solubility in water | 28.39 g/100 g (25 °C) 43.1 g/100 g (80 °C) |
| Hazards[2] | |
| Material safety data sheet (MSDS) | ICSC |
| GHS pictograms |   
|
| GHS signal word | DANGER |
| GHS hazard statements | H272, H301, H315, H319, H341, H351, H361 |
| GHS precautionary statements | P201, P202, P210, P220, P221, P264, P270, P280, P281, P301+312, P302+352, P305+351+338, P308+313, P321 |
| Related compounds | |
| Other anions | Sodium chlorate Sodium iodate |
| Other cations | Lithium bromate Potassium bromate Rubidium bromate Caesium bromate |
| Other compounds | Sodium bromide Sodium hypobromite Sodium bromite Sodium perbromate |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
Sodium bromate, NaBrO3, is the sodium salt of bromic acid. It is used as a neutralizer-oxidizer in hair-wave preparations and in textile bleaching.[1]
Preparation
Sodium bromate is usually prepared by the electrolysis of sodium 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 sodium bromate can be crystallized by cooling the electrolyte, and any unoxidized bromide recycled.[1]
Sodium bromate can also be prepared by reacting bromine with sodium 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]
Another approach is to oxidize the remaining bromide with chlorine:[5]
- Br2 + 2 Cl2 + 6 OH− → 2 BrO−3 + 4 Cl− + 6 H+
Notes and references
Notes
References
- ↑ 1.0 1.1 1.2 1.3 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.
- ↑ HSNO Chemical Classification Information Database, <http://www.ermanz.govt.nz/Chemicals/ChemicalDisplay.aspx?SubstanceID=1800> (accessed 3 January 2011), New Zealand Environmental Risk Management Authority.
- ↑ 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.
- ↑ Zhao, Naizhi; Wu, Zongsheng; Sun, Guishi (Daqinghe Saltern) 溴酸钠的生产方法 (Method of preparing sodium bromate). CN Patent 1102818, published 24 May 1995.
External links
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See also the corresponding article on Wikipedia. |
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