Sodium bromate

Crystal structure
__ Na + __ Br 5+ __ O 2−
Crystal system	cubic
Space group	P 2 1 3 (No. 198)
Lattice parameters	a 6.70717 Å
General
Surname	Sodium bromate
other names	Sodium bromate (V)
Ratio formula	NaBrO 3
Brief description	colorless odorless solid
External identifiers / databases
CAS number 7789-38-0 EC number 232-160-4 ECHA InfoCard 100.029.237 PubChem 23668195 Wikidata Q414567
properties
Molar mass	150.89 g mol −1
Physical state	firmly
density	3.34 g cm −3
Melting point	381 ° C (decomposition)
solubility	Easily soluble in water (364 g l −1 at 20 ° C)
Refractive index	1.6168
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 271-302-315-319-335-341-350 P: 210-221-283-305 + 351 + 338-306 + 360-370 + 380 + 375-420-501
Toxicological data	140 mg kg −1 ( LD 50 ,  mouse ,  ip ) 250 mg kg −1 ( LD 50 ,  rabbit ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Sodium bromate is a chemical compound from the groups of sodium compounds and bromates .

Extraction and presentation

Sodium bromate can be represented by the reaction of liquid bromine with a solution of sodium hydroxide :

${\displaystyle {\ce {3Br2 + 6Na+ + 6OH- <=> 6Na+ + BrO3- + 5Br- + 3H2O}}}$

This leaves five molecules of NaBr and one molecule of sodium bromate (NaBrO ₃ ).

Sodium bromate can also be obtained by dissolving sodium carbonate in water and then reacting it with bromine.

properties

Sodium bromate is a colorless, odorless, hygroscopic solid that is a strong oxidizing agent . It decomposes above 381 ° C, producing oxygen . It crystallizes cubically , space group P 2 ₁ 3 (space group no. 198) , with the lattice parameter a = 6.707 Å .

The salt is very soluble in water. The solubility increases with increasing temperature.

solubility in water
temperature	in ° C	0	20th	40	60	80	100
solubility	in g / 100 g H 2 O	27.5	36.4	48.8	62.6	75.8	90.8

use

Sodium bromate is used as an oxidizing agent (e.g. as a bleaching agent and in textile dyeing) and as a piezoelectric single crystal. In combination with sodium bromide , it is used in gold washing. In organic chemistry, sodium bromate is used as a bromination reagent for aromatic compounds such as nitrobenzene , benzoic acid and benzaldehyde .

Related links

• Sodium bromite NaBrO ₂ , CAS number: 7486-26-2
• Sodium chlorate

Individual evidence

1. ↑ ^{a b} S. C. Abrahams, JL Bernstein: Remeasurement of optically active NaClO ₃ and NaBrO ₃ . In: Acta Crystallographica . B33, 1977, pp. 3601-3604, doi: 10.1107 / S0567740877011637 .
2. ↑ ^{a b c d e f g h} Entry on sodium bromate in the GESTIS substance database of the IFA , accessed on January 8, 2018(JavaScript required) .
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Index of Refraction of Inorganic Crystals, pp. 10-247.
4. ↑ Sodium bromate data sheet , ≥99% from Sigma-Aldrich , accessed on May 18, 2017 ( PDF ).
5. ↑ ^{a b c d e} D. Yoffe, R. Frim, SD Ukeles, MJ Dagani, HJ Barda, TJ Benya, DC Sanders: Bromine Compounds. In: Ullmann's Encyclopedia of Technical Chemistry . Wiley-VCH Verlag, Weinheim 2013, doi : 10.1002 / 14356007.a04_405.pub2 .
6. ↑ Production of bromine compounds (Weizmann) (PDF; 4.8 MB)
7. ↑ ^{a b} Bromine, Inorganic Compounds (ICL)  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.  
8. ↑ A. Groweiss: Use of Sodium bromate for Aromatic Bromination: Research and Development. In: Org. Process Res. Dev. 4, 2000, pp. 30-33, doi: 10.1021 / op9901947 .