Chromous Orthophosphate, Cr₃(PO₄)₂

Chromous Orthophosphate, Cr₃(PO₄)₂.H₂O, is the abundant blue gelatinous precipitate obtained when ordinary sodium phosphate is added to chromous chloride solution. It is readily soluble in acids, and on exposure to air rapidly changes to the green chromic salt. It does not form double salts with ammonium phosphate.