Barium bromate

Barium bromate IUPAC name Barium bromate Other names Barium bromate(V) Identifiers InChI InChI=1/Ba.2BrHO3/c;2*2-1(3)4/h;2*(H,2,3,4)/q+2;;/p-2 InChIKey VEASZGAADGZARC-NUQVWONBAI Standard InChI InChI=1S/Ba.2BrHO3/c;2*2-1(3)4/h;2*(H,2,3,4)/q+2;;/p-2 Standard InChIKey VEASZGAADGZARC-UHFFFAOYSA-L ChemSpider 55607 Properties Chemical formula Ba(BrO3)2 Molar mass 393.13 g mol−1 Appearance white crystalline solid Melting point 270 °C decomp. Related compounds Other anions Barium chlorate Barium iodate Other cations Calcium bromate Strontium bromate Other compounds Barium bromide Barium hypobromite Barium bromite Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Barium bromate monohydrate IUPAC name Barium bromate — water (1/1) Identifiers Standard InChI InChI=1S/Ba.2BrHO3.H2O/c;2*2-1(3)4;/h;2*(H,2,3,4);1H2/q+2;;;/p-2 Standard InChIKey SRLAISWMODXCQE-UHFFFAOYSA-L CAS number [10326-26-8] Properties Chemical formula Ba(BrO3)2·H2O Molar mass 411.15 g mol−1 Appearance white crystalline solid Density 4.0 g cm−3 Melting point 180–200 °C dehydr. Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Barium bromate, Ba(BrO₃)₂, is the barium salt of bromic acid. It is used as a corrosion inhibitor.

Preparation

Barium 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. The sodium bromate can be crystallized by cooling the electrolyte, and any unoxidized bromide recycled.

Barium bromate can also be prepared by reacting bromine with sodium hydroxide solution at 50–90 °C.

3 Br₂ + 3 OH⁻ ⇌ BrO−3 + 5 Br⁻ + 3 H⁺

Decomposition

Anhydrous barium bromate decomposes at about 270 °C to give barium bromide and oxygen:

Ba(BrO₃)₂ → BaBr₂ + 3 O₂

Controlled decomposition in vacuo at 250 °C gives barium bromite:

Ba(BrO₃)₂ → Ba(BrO₂)₂ + O₂