Potassium periodate

Potassium periodate has formula KIO4.

Density is 3,618 kg m-3. It melts at 581.85 °C.

It is slightly soluble in water (one of the less soluble of potassium salts, owing to a large anion), giving rise to a solution that is slightly alkaline. On heating (especially with manganese(IV) oxide as catalyst), it decomposes to form potassium iodate, releasing oxygen gas.

The low solubility of KIO4 makes it useful for the determination of potassium.

Note that the pronunciation is per-iodate, not period-ate.