Sodium bromate

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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 [7789-38-0]
EC number 232-160-4
ChemSpider 23009
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)
Related compounds
Other anions Sodium chlorate
Sodium iodate
Other cations Potassium 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 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.[2] 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.[3]

3 Br2 + 3 OH BrO3 + 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. Another approach is to oxidize the remaining bromide with chlorine:[4]

Br2 + 2 Cl2 + 6 OH → 2 BrO3 + 4 Cl + 6 H+

Notes and references

Notes

References

  1. 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.
  2. Osuga, Takasi; Sugino, Kiichiro Electrolytic Production of Bromates. J. Electrochem. Soc. 1957, 104 (7), 448–51. DOI: 10.1149/1.2428623.
  3. 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.
  4. Zhao, Naizhi; Wu, Zongsheng; Sun, Guishi (Daqinghe Saltern) (Method of preparing sodium bromate). CN Patent 1102818.

External links

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