Barium iodate

When concentrated aqueous solutions of barium nitrate, Ba(NO )2, and ammonium iodate, NH4I03, are mixed, insoluble barium iodate, Ba(I03)2, forms. The chemical equation for the precipitation reaction is... 

Barium bromate, 0202 Barium iodate, Barium iodate, 0211 Bromic acid, 0248 Lead bromate, 0278... 

Iodic acid may be prepared by the reaction of sulfuric acid with barium iodate. The solution is fdtered to remove barium sulfate and then crystaUized to obtain iodic acid ... 

Ammonium iodate, NH4IO3.—This salt is formed by H. Kammerer68 as a sparingly soluble white crystalline powder by the neutralisation of aq. iodic acid, or iodine trichloride with ammonia or ammonium carbonate from iodine water and ammonia from cold soln. of ammonium carbonate and barium iodate. A. Guyard, and F. D. Chattaway and K. J. P. Orton, also noticed that when nitrogen iodide is suspended in aqua ammonia and exposed to sunlight, ammonium iodide and iodate are formed. 

W. D. Harkins and W. J. Winninghoff have measured the effect of variohs salts on the solubility of barium iodate. The b.p. of the sat. soln. at 735 mm. is 99 2°. The soln. in cold hydrochloric acid decomposes. Barium iodate is slightly soluble in warm nitric acid, and, according to W. Eidmann, insoluble in acetone. 

Potassium iodide can also be obtained from the aq. extract of kelp or from the mother liquid remaining after the separation of sodium chloride and potassium sulphate from sea-water by evaporation. In E. Allary and J. Pellieux process,8 the liquid is evaporated to dryness and roasted in a special furnace so as to avoid a loss of iodine. The product is fractionally extracted with cold water, when a soln. is obtained which on evaporation gives a residue with 50 per cent, of alkali iodide. This product is extracted.in a special digester with 50 per cent, alcohol. The solvent dissolves little more than the iodides. The alcohol is distilled off, and on evaporation a residue containing about 34 per cent, of potassium iodide, and 66 per cent, of sodium iodide is obtained. To convert the latter into potassium iodide, the proper quantity of a soln. of potassium carbonate is added and carbon dioxide passed into the liquid whereby sodium bicarbonate is precipitated. The precipitate is separated by a filter press, and the small amount of sodium bicarbonate remaining in the soln. is separated by the addition of a little hydrochloric acid and the sodium chloride and potassium iodide separated by fractional crystallization. In E. Sonstadt s process, the mother liquid is treated with chlorine mixed with potassium chlorate or permanganate so as to convert the iodine into iodate. A soln. of a barium salt is added, and the barium iodate treated with potassium sulphate. Barium sulphate is precipitated, and the soln. of potassium iodate is evaporated to dryness and calcined to convert the iodate to iodide. The latter is purified by crystallization. 

Barium iodate (H2O) [10567-69-8] M 505.2. Crystd from a large volume of hot water by cooling. 

Twenty grams of barium iodate monohydrate are added with mechanical stirring to 120ml of gently boiling IN sulfuric acid. Heating and agitation are maintained for about one hour a little water is added from time to time... 

Barium bromate, 0202 Barium iodate, 0211 Bromic acid, 0248 Lead bromate, 0277 Mercury(I) bromate, 0270 Potassium iodate, 4614 Silver iodate, 0020 Sodium iodate, 4619 Zinc bromate, 0278 See other METAL OXOHALOGENATES... 

Hypoiodites. — The formation of hypoiodites is analogous to that of hypochlorites but the salts are known only in solution mixed with iodide. Again, like the hypochlorites, they change on heating they yield a mixture of iodide and iodate and from barium iodate iodic acid can be prepared. But it is more readily obtained by boiling iodine with nitric acid for iodine is more easily oxidised than either chlorine or bromine or chlorine and water may be used as an oxidising agent. 

Barium chloride White precipitate of barium iodate sparingly soluble in hot water or dilute nitric acid insoluble in ethanol and methanol... 

IV.21 IODATES, IO3 Solubility The iodates of the alkali metals are soluble in water those of the other metals are sparingly soluble and, in general, less soluble than the corresponding chlorates and bromates. Some solubilities in g -1 at 20° are lead iodate 0 03 (25°), silver iodate 0-06, barium iodate O 22, calcium iodate 3-7, potassium iodate 81-3, and sodium iodate 90 0. Iodic acid is a crystalline solid, and has a solubility of 2,330 g t 1 at 20°. 

Barium chloride solution white precipitate of barium iodate (difference from chlorate), sparingly soluble in hot water and in dilute nitric acid, but insoluble in alcohol (difference from iodide). If the precipitate of barium iodate is well washed, treated with a little sulphurous acid solution and 1-2 ml carbon tetrachloride, the latter is coloured violet by the liberated iodine, and barium sulphate is precipitated ... 

Action of heat The alkali iodates decomposed into oxygen and an iodide. Most iodates of the bivalent metals yield iodine and oxygen and leave a residue of oxide barium iodate, exceptionally, gives the periodate (more precisely, hexoxoperiodate) ... 

An iodate does not react with concentrated sulphuric acid in the cold or upon gentle heating. A solution of an iodate gives with silver nitrate solution a white precipitate of silver iodate, insoluble in m nitric acid but soluble in dilute ammonia solution, thus simulating the behaviour of a chloride towards these reagents. Iodates, however, give a white precipitate of barium iodate, Ba(I03)2, with barium chloride solution the precipitate is sparingly soluble in dilute nitric acid. 

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