Strontium Dichromate, SrCr₂O₇.3H₂O

Strontium Dichromate, SrCr₂O₇.3H₂O, is formed by dissolving the normal chromate in chromic acid solution and allowing to crystallise, or by treating freshly precipitated strontium chromate with solid chromic anhydride. It yields large reddish-brown monoclinic crystals,

a:b:c = 0.6023:1:0.5460; γ = 87° 28',

readily soluble in water. On heating, the water of crystallisation is completely expelled at 110° C.

The additive compound SrCr₂O₇.SrCl₂.4HgCl₂.H₂O has been obtained.