Iodic acid, potassium salt
3D model (JSmol)
|E number||E917 (glazing agents, ...)|
|Molar mass||214.001 g/mol|
|Appearance||white crystalline powder|
|Melting point||560 °C (1,040 °F; 833 K) (decomposes)|
|4.74 g/100 mL (0 °C)
9.16 g/100 mL (25 °C)
32.3 g/100 mL (100 °C)
|Solubility||soluble in KI solution
insoluble in alcohol, liquid ammonia, nitric acid
|R-phrases (outdated)||R9, R22, R36, R37, R38|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Potassium iodate is an oxidizing agent and as such it can cause fires if in contact with combustible materials or reducing agents. It can be prepared by reacting a potassium-containing base such as potassium hydroxide with iodic acid, for example:
It can also be prepared by adding iodine to a hot, concentrated solution of potassium hydroxide.
- KI + KClO3 → KIO3 + KCl
Potassium iodate is sometimes used for iodination of table salt to prevent iodine deficiency. Because iodide can be oxidized to iodine by molecular oxygen under wet conditions, US companies add thiosulfates or other antioxidants to the potassium iodide. In other countries, potassium iodate is used as a source for dietary iodine. It is also an ingredient in some baby formula milk.
Potassium iodate may be used to protect against accumulation of radioactive iodine in the thyroid by saturating the body with a stable source of iodine prior to exposure. Approved by the World Health Organization for radiation protection, potassium iodate (KIO3) is an alternative to potassium iodide (KI), which has poor shelf life in hot and humid climates. The UK, Singapore, United Arab Emirates, and the U.S. states Idaho and Utah are known[by whom?] to stock potassium iodate in tablet form. The government of Ireland also, following the September 11 attacks, issued potassium iodate tablets to all households. It is not approved by the U.S. Food and Drug Administration (FDA) for use as a thyroid blocker, and the FDA has taken action against US websites that promote this use.
|Age||KI in mg||KIO3 in mg|
|Over 12 years old||130||170|
|3 – 12 years old||65||85|
|1 – 36 months old||32||42|
|< 1 month old||16||21|
|This article needs additional citations for verification. (January 2009) (Learn how and when to remove this template message)|
- Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
- Astbury, John; Horsley, Stephen; Gent, Nick (1999), "Evaluation of a scheme for the pre-distribution of stable iodine (potassium iodate) to the civilian population residing within the immediate countermeasures zone of a nuclear submarine construction facility", Journal of Public Health, 21 (4): 2008–10, PMID 11469363, doi:10.1093/pubmed/21.4.412
- Pahuja, D.N.; Rajan, M.G.; Borkar, A.V.; Samuel, A.M. (Nov 2008), "Potassium iodate and its comparison to potassium iodide as a blocker of 131I uptake by the thyroid in rats", Health physics, 65 (5): 545–9, PMID 8225995, doi:10.1097/00004032-199311000-00014
- Guidelines for Iodine Prophylaxis following Nuclear Accidents (PDF), Geneva: World Health Organization, 1999