Potassium iodate

• Potassium iodate
• Iodsaures potassium

White crystalline solid

Fixed

3.98 g · cm -3

560 ° C ( decomposition)

Moderately in water ( 92 g · l-1 at 25 ° C)

Risk

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Potassium is the potassium salt of iodic acid. The white, crystalline solid is oxidizing and can be used as an oxidant.

Production

Iodate can be obtained from iodine and hot alkali solution. The result of iodine and potassium iodate hot potassium hydroxide solution:

This reaction is analogous to the preparation of chlorates of chlorine and hot water.

Properties and Uses

Potassium forms colorless crystals which are moderately soluble in water. The solubility increases with increasing temperature.

Iodates are marked oxidant. If their solutions are acidified, they are in equilibrium with their acid before; the solution then acts strongly oxidizing where the oxidation potential of 1.196 V. React with iodide iodate in acid solution to iodine, so there is a comproportionation instead:

This reaction is a reaction part of the Landolt reaction in which a color change takes place only after a certain time, and is preferably used in the potassium iodate.

The most important applications of potassium iodate are in analytical chemistry, where it is used as a primary standard.

Iodized table salt contains about 20 ppm of potassium or sodium iodate (0.020 mg / g). Potassium iodide can not use this, because it can be too easily oxidized. Medical iodine deficiency tablets contain about the recommended daily allowance, approximately 0.1 mg / piece. Special radiation protection iodine tablets, however, are dosed with 100 mg / unit by a factor of 1000 higher.

Safety

Iodate are away as a strong oxidizing agent from reducing agents such as sulfur, metal powders and organic substances. In animal experiments with rabbits potassium iodate showed strong irritation to the eyes and skin.