Potassium iodate

Potassium iodate (KIO₃) is an ionic inorganic compound with the formula KIO₃. It is a white salt that is soluble in water.^[1]

Potassium iodate

Names
IUPAC name Potassium iodate
Other names Iodic acid, potassium salt
Identifiers
CAS Number	7758-05-6 Y
3D model (JSmol)	Interactive image
ChemSpider	22856 Y
DrugBank	DB15923
ECHA InfoCard	100.028.938
EC Number	231-831-9
E number	E917 (glazing agents, ...)
PubChem CID	23665710
RTECS number	NN1350000
UNII	I139E44NHL Y
CompTox Dashboard (EPA)	DTXSID5058480
InChI InChI=1S/HIO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 Y Key: JLKDVMWYMMLWTI-UHFFFAOYSA-M Y InChI=1/HIO3.K/c2-1(3)4;/h(H,2,3,4);/q;+1/p-1 Key: JLKDVMWYMMLWTI-REWHXWOFAL
SMILES [K+].[O-]I(=O)=O
Properties
Chemical formula	KIO3
Molar mass	214.001 g/mol
Appearance	white crystalline powder
Odor	odorless
Density	3.89 g/cm3
Melting point	560 °C (1,040 °F; 833 K) (decomposes)
Solubility in water	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
Magnetic susceptibility (χ)	−63.1·10−6 cm3/mol
Hazards
GHS labelling:
Pictograms
Hazard statements	H272, H302, H318
Precautionary statements	P210, P280, P301+P312+P330, P305+P351+P338+P310
NFPA 704 (fire diamond)	2 0 2 OX
Flash point	Non-flammable
Related compounds
Other anions	Potassium chlorate Potassium bromate
Other cations	Sodium iodate
Related compounds	Potassium iodide Potassium periodate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation and properties

It can be prepared by reacting a potassium-containing base such as potassium hydroxide with iodic acid, for example:^[1]

HIO₃ + KOH → KIO₃ + H₂O

It can also be prepared by adding iodine to a hot, concentrated solution of potassium hydroxide:^[1]

3 I₂ + 6 KOH → KIO₃ + 5 KI + 3 H₂O

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:^[2]

KI + KClO₃ → KIO₃ + KCl

The analogous reaction with potassium hypochlorite is also possible:^[3]

KI + 3KOCl → 3KCl + KIO₃

Conditions/substances to avoid include: heat, shock, friction,^[4] combustible materials,^[1] reducing materials, aluminium,^[4] organic compounds,^[1] carbon, hydrogen peroxide and sulfides.^[4]

Applications

Potassium iodate is sometimes used for iodination of table salt to prevent iodine deficiency. In the US, iodized salt contains antioxidants, because atmospheric oxygen can oxidize wet iodide to iodine; other countries simply use potassium iodate instead.^[5] Salt mixed with ferrous fumarate and potassium iodate, "double fortified salt", are used to address both iron and iodine deficiencies.^[6] Potassium iodate is also used to provide iodine in some baby formula.^[7]

Like potassium bromate, potassium iodate is occasionally used as a maturing agent in baking.^[8]

Radiation protection

An unopened box of potassium iodate tablets distributed in the early 2000s to Irish households in case of a terror attack on British nuclear facilities.

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.^[9] 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.^[10] The UK, Singapore, United Arab Emirates, and the U.S. states Idaho and Utah all maintain potassium iodate tablets towards this end.^{[citation needed]} Following the September 11 attacks, the government of Ireland issued potassium iodate tablets to all households for a similar purpose.^[11]

Recommended Dosage for Radiological Emergencies involving radioactive iodine^[12]

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

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.^[13][14]

Safety

Potassium iodate is an oxidizing agent and as such it can form explosive mixtures when combined with organic compounds.^[1]