An iodate is the polyatomic anion with the formula IO−3. It is the most common form of iodine in nature, as it comprises the major iodine-containing ores. Iodate salts are often colorless. They are the salts of iodic acid.
The iodate anion, IO−3
Space-filling model of the iodate anion
3D model (JSmol)
|Molar mass||174.902 g·mol−1|
|Periodate, Fluoroiodate, Bromate, Chlorate|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Iodate is pyramidal in structure. The O–I–O angles range from 97° to 105°, somewhat smaller than the O–Cl–O angles in chlorate.
Iodate is one of several oxyanions of iodine, and has an oxidation number of +5. It participates in several redox reactions, such as the iodine clock reaction. Iodate shows no tendency to disproportionate to periodate and iodide, in contrast to the situation for chlorate.
- 6HSO−3 + 2IO−3 → 2I− + 6HSO−4
Iodate oxidizes iodide:
- 5I− + IO−3 + 3H2SO4 → 3I2 + 3H2O + 3SO4^−2
Similarly, chlorate oxidizes iodide to iodate:
- I− + ClO−3 → Cl− + IO−3
- IO−3 + HIO3 → H(IO3)−2
The anion H(IO3)−2 is referred to as biiodate.
Principal compounds Edit
- Calcium iodate, Ca(IO3)2, is the principal ore of iodine. It is also used as a nutritional supplement for cattle.
- Potassium iodate, KIO3, like potassium iodide, has been issued as a prophylaxis against radioiodine absorption in some countries.
- Potassium hydrogen iodate (or potassium biiodate), KH(IO3)2, is a double salt of potassium iodate and iodic acid, as well as an acid itself.
- When some oxygen is replaced by fluorine, fluoroiodates are produced.
Natural occurrence Edit
- Lyday, Phyllis A. (2005). "Iodine and Iodine Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. pp. 382–390. doi:10.1002/14356007.a14_381.
- Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
- Qiu, Chao; Sheng Han; Xingguo Cheng; Tianhui Ren (2005). "Distribution of Thioethers in Hydrotreated Transformer Base Oil by Oxidation and ICP-AES Analysis" (abstract). Industrial & Engineering Chemistry Research. 44 (11): 4151–4155. doi:10.1021/ie048833b. Retrieved 2007-05-03.
Thioethers can be oxidized to sulfoxides by periodate, and periodate is reduced to iodate
- "Radiological Protection Institute of Ireland | | Media | Press releases | Radioactivity released from Wylfa nuclear power plant is extremely low and of no health significance". Archived from the original on 2013-10-17. Retrieved 2013-04-08.
- "Decision to Discontinue the Future Distribution of Iodine Tablets". Archived from the original on 2013-10-18. Retrieved 2013-05-22.
- "Home". mindat.org.