Potassium iodate

From Wikipedia, the free encyclopedia

Potassium iodate
Other names	iodic acid, potassium salt
Identifiers
CAS number	[7758-05-6]
Properties
Molecular formula	KIO₃
Molar mass	214.00 g/mol
Appearance	white crystalline powder
Density	3.89 g/cm³, solid
Melting point	560°C partial decomposition
Solubility in water	32g/100ml (100°C)
Hazards
EU classification	not listed
Related compounds
Other anions	potassium iodide potassium periodate potassium bromate potassium chlorate
Other cations	sodium iodate silver iodate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Potassium iodate (K I O₃) is a chemical compound. It is sometimes used in radiation treatment, as it can replace radioactive iodine from the thyroid.

[edit] Chemical properties

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:

HIO₃ + KOH → KIO₃ + H₂O

It can also be prepared by adding iodine to a hot, concentrated solution of potassium hydroxide.

3 I₂ + 6 KOH → KIO₃ + 5 KI + 3 H₂O

Conditions/substances to avoid include: heat, shock, friction, combustible materials, reducing materials, aluminium, organic compounds, carbon, hydrogen peroxide and sulfides.

[edit] Use

Potassium iodate is used for iodination of table salt, because iodide can be oxidized by molecular oxygen to iodine under wet conditions. To prevent this US companies add thiosulfates or other antioxidants to the potassium iodide, while in some other countries potassium iodate is used as source for iodine. It is also an ingredient in baby formula milk.

Potassium iodate may be used to protect against accumulation of radioactive iodine in the thyroid by saturating the body with an alternative source of iodine. Only potassium iodide has been tested and approved for this use by FDA and hence potassium iodate is not approved in the U.S. for this purpose, although it is used in some other countries such as the Republic of Ireland (see illustration).

Like potassium bromate, potassium iodate is occasionally used as a maturing agent in baking.

An unopened box of potassium iodate tablets, produced and distributed to the population of the Republic of Ireland in case of a terror attack on the Sellafield nuclear power station in the United Kingdom.

Recommended Dosage for Radiological Emergencies involving radioactive iodine^[1]
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

[edit] References

This article does not cite any references or sources. (November 2007)
Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed.