Potassium iodate (PotassiumIodineOxygen) is an ionic compound inorganic compound with the formula . It is a white salt that is soluble in water.
Preparation and properties
It can be prepared by reacting a potassium-containing base such as potassium hydroxide with
iodic acid, for example:
- Iodic acid + KOH → KIO3 + Water
It can also be prepared by adding iodine to a hot, concentrated solution of potassium hydroxide:
- 3 iodine + 6 KOH → KIO3 + 5 potassium iodide + 3 water
Or by fusing potassium iodide with potassium chlorate, bromate or perchlorate, the melt is extracted with water and potassium iodate is isolated from the solution by crystallization:[Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ]
- KI + KClO3 → KIO3 + KCl
The analogous reaction with potassium hypochlorite is also possible:
KI + 3KOCl → 3KCl + KIO3
Conditions/substances to avoid include:
heat, shock,
friction,
combustible materials,
reducing materials,
aluminium,
organic compounds,
, hydrogen peroxide and
.
Applications
Potassium iodate is sometimes used for iodination of table salt to prevent iodine deficiency. In the US,
Iodised salt contains
, because atmospheric oxygen can oxidize
Aqueous solution iodide to iodine; other countries simply use potassium iodate instead.
Salt mixed with
ferrous fumarate and potassium iodate, "double fortified salt", are used to address both iron and iodine deficiencies.
Potassium iodate is also used to provide iodine in some
Infant formula.
Like potassium bromate, potassium iodate is occasionally used as a maturing agent in baking.
Radiation protection
Potassium iodate may be used to protect against accumulation of
radioiodine 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 (KIO
3) is an alternative to
potassium iodide, which has poor
shelf life in hot and humid
.
The UK,
Singapore, United Arab Emirates, and the U.S. states
Idaho and
Utah all maintain potassium iodate tablets towards this end. Following the September 11 attacks, the government of Ireland issued potassium iodate tablets to all households for a similar purpose.
+ Recommended Dosage for Radiological Emergencies involving radioactive iodine |
| Over 12 years old | 130 | 170 |
| 3 – 12 years old | 65 | 85 |
| 1 – 36 months old | 32 | 42 |
| < 1 month old | 16 | 21 |
Potassium iodate 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.
Safety
Potassium iodate is an
oxidizing agent and as such it can form explosive mixtures when combined with organic compounds.
