Potassium periodate is an inorganic salt with the molecular formula . It is composed of a potassium cation and a periodate anion and may also be regarded as the potassium salt of periodic acid. Note that the pronunciation is per-iodate, not period-ate.
Unlike other common periodates, such as sodium periodate and periodic acid, it is only available in the meta-periodate form; the corresponding potassium ortho-periodate () has never been reported.
Preparation
Potassium periodate can be prepared by the oxidation of an aqueous solution of potassium iodate by chlorine and potassium hydroxide.
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It can also be generated by the electrochemical oxidation of potassium iodate, however the low solubility of makes this approach of limited use.
Chemical properties
Potassium periodate decomposes at to form potassium iodate and oxygen.
The low solubility of makes it useful for the determination of potassium and cerium.
On heating (especially with manganese(IV) oxide as catalyst), it decomposes to form potassium iodate, releasing oxygen gas.