Sodium iodate sulphate

Formerly all the iodine was made from the ash of seaweed, and potash was a remunerative appendix to the iodine industry but just as the Stassfurt salts killed those industries which extracted potash from other sources, so did the separation of iodine from the caliche mother-liquors threaten the industrial extraction of iodine from seaweed with extinction. Iodine in a very crude form was exported from Chili in 1874—e.g. a sample was reported with iodine 52-5 per cent. iodine chloride, 3-3 sodium iodate, 13 potassium and sodium nitrate and sulphate, 15 9 magnesium chloride, 0 4 insoluble matter, 1 5 water, 25-2 per cent. About that time much of the iodine was imported as cuprous iodide. This rendered necessary the purification of the Chilian product but now the iodine is purified in Chili before it is exported. The capacity of the Chilian nitre works for the extraction of iodine is greater than the world s demand. It is said that the existing Chilian factories could produce about 5100 tons of iodine per annum whereas the... 

A. Connell (1802) 140 obtained a white precipitate—ferrous iodate—by boiling a soln. of iron in iodic acid, and C. F. Rammelsberg found that the addition of potassium iodate to ferrous sulphate gives a yellowish-white precipitate which is decomposed when heated. It is sparingly soluble in nitric acid, and it dissolves in an excess of ferrous sulphate, and the soln., when heated, precipitates basic ferric iodate. A. Ditte mixed boiling soln. of a ferric salt and an alkali iodate and obtained a brown precipitate—ferric iodate—insoluble in hot nitric acid diluted with its own volume of water. Crystals can be obtained by mixing warm dil. soln. of ferric nitrate, acidified with nitric acid, and sodium iodate. The precipitate... 

Stir 2.35 g (0.011 mol) of sodium metaperiodate (Section 4.2.55, p. 454) in 45 ml of a 1 1 mixture of water and methanol held at 0°C. Add portionwise 2.14 g (0.01 mol) of dibenzyl sulphide (Expt 5.204) and continue to stir the mixture at 0 °C for several hours, preferably overnight. Extract the reaction mixture (which contains precipitated sodium iodate) with three 20 ml portions of chloroform. Dry the combined chloroform extracts over magnesium sulphate and remove the solvent on a rotary evaporator. Recrystallise the product from ethanol. The yield of dibenzyl sulphoxide is 2.2 g (96%), m.p. 135 °C. 

A monohydrate, Ni(I03)2.H20, was obtained by Rammelsberg4 as a bright green powder by concentrating solutions of nickel sulphate and sodium iodate or a solution of nickel hydroxide in aqueous hydriodic acid. Clarke 5 was unable to find this salt. 

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. 

Reaction of Potassium lodate with Sodium Sulphite in a Sulphate Medium. Pour 20jml of a sodium sulphite solution acidified with sulphuric acid and containing a small amount of starch into a 100-ml beaker. Pour 20 ml of a potassium iodate solution into a second 100-ml beaker. The potassium iodate solution must contain... 

Magnesium carbonate V Manganese carbonate P. 70 Manganese dioxide, powder IV, XI Nickel carbonate XI Phosphorus, red II, X Porcelain chips, unglazed E. 5, P. 56 Potassium carbonate IX Potassium chlorate III, VIII Potassium dichromate IV Potassium hydroxide II, III Potassium iodate VIII Potassium iodide IV, VIII Potassium nitrate IV, XI Potassium permanganate IV, VIII Potassium sulphate Q. 3 Silicon dioxide, precipitated IX Silicon dioxide, coarse sand P. 66, 67 Silicon dioxide, fine sand P. 8, 43 Sodium bicarbonate P. 55 Sodium bromide IV Sodium carbonate, anhydrous III, IX, XI... 

In alkaline solution, the permanganate is decolourized, but manganese dioxide is precipitated. In the presence of sodium hydroxide solution, potassium iodide is converted into potassium iodate, and sodium sulphite solution into sodium sulphate on boiling. 

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