Strontium Periodate, Sr(IO₄)₂.6H₂O

Strontium Periodate, Sr(IO₄)₂.6H₂O, is obtained by solution of strontium carbonate in excess of periodic acid and evaporation over sulphuric acid in the cold. It separates in large monoclinic crystals with 6 molecules of water. By dehydration over sulphuric acid the dihydrate is formed. The aqueous solution has an acid reaction.

If periodic acid be practically neutralised with strontium carbonate, or if strontium hydroxide be precipitated with sodium periodate, an insoluble basic salt of composition SrO.Sr(IO₄)₂.4 or 3H₂O is formed.