Barium Bromate, Ba(BrO₃)₂

Barium Bromate, Ba(BrO₃)₂, may be prepared by precipitation from boiling solutions of potassium bromate and barium chloride, or, preferably, acetate. It is also formed by the action of barium hydroxide on bromine chloride, and by the action of bromine on a boiling solution of barium hydroxide. It forms monoclinic prisms, of density 3.82, isomorphous with the chlorate and containing 1 molecule of water of crystallisation, which is not removed until a temperature of 170° C. is reached. At about 260° C. the salt begins to decompose. The decomposition apparently takes place in two stages, because there is an intermediate slowing down. Potilitzin attributes this to the formation of two isomeric bromates, BaO₂.Br₂O₄ and Ba(BrO₃)₂, bromine being penta-valent in the first and heptavalent in the second.

The following values have been obtained for the solubility at different temperatures: -

Temperature, °C.	-0.034±0.002° cryohydric point	0	10	20	30	40	50	60	70	80	90	98.7	100.39° boiling-point
Grams Ba(BrO3)2 per 100 grams solution	0.280	0.286	0.439	0.652	0.95	1.31	1.72	2.271	2.922	3.521	4.260	5.256	5.39

The solubility is increased by potassium nitrate and diminished by barium nitrate and potassium bromate.