Barium Iodate, Ba(IO3)2, is obtained by precipitating a soluble barium salt with sodium iodate in dilute boiling solutions, by treating barium hydroxide with excess of iodic acid, or by the action of iodine on powdered barium hydroxide. The precipitate is composed of small opaque monoclinic prisms containing 1 molecule of water of crystallisation, but it may be obtained in clear crystals by recrystallisation from nitric acid. It is isomorphous with the bromate and chlorate, loses its water at 180° C., and is decomposed by heat, giving off oxygen and iodine. The decomposition takes place explosively in contact with carbon. Sulphuric acid liberates iodine from barium iodate.
The solubility, even in hot water, is only small. In 100 grm. of the solution at 20° C. there is 0.022 grm. of the anhydrous salt. |