Iodate


An iodate is a conjugate base of iodic acid. In the iodate anion, iodine is bonded to three oxygen atoms and the molecular formula is. The molecular geometry of iodate is trigonal pyramidal.
Iodate can be obtained by reducing a periodate with a sulfide. The byproduct of the reaction is a sulfoxide.
Iodates are a class of chemical compounds containing this group. Examples are sodium iodate, silver iodate, and calcium iodate. Iodates resemble chlorates with iodine instead of chlorine.
In acidic conditions, iodic acid is formed. Potassium hydrogen iodate is a double salt of potassium iodate and iodic acid and an acid as well. Iodates are used in the iodine clock reaction.
Potassium iodate, like potassium iodide, has been issued as a prophylaxis against radioiodine absorption in some countries.

Other oxyanions

can assume oxidation states of −1, +1, +3, +5, or +7. A number of neutral iodine oxides are also known.
Iodine oxidation state−1+1+3+5+7
Nameiodidehypoioditeioditeiodateperiodate
FormulaI−IO− or

Natural occurrence

Minerals containing essential iodate anions are very rare. They are almost exclusively known from the caliche deposits of Chile. The deposits stand for the main source of nitrates, but iodate- and chromate-bearing minerals are also present there. The most important iodate minerals are lautarite and brüggenite, but also copper-bearing iodates are known. In the iodate minerals iodine is always pentavalent, i.e., present as the anions.