Calcium Orthoplumbate, Ca₂PbO₄

Calcium Orthoplumbate, Ca₂PbO₄, is obtained as a reddish compound by the action of air at red heat on a mixture of lead oxide and calcium carbonate. Kassner suggested the use of this compound for the extraction of oxygen from the air. At 880° C. the dissociation tension is 47 mm., and at 1100° C. 940 mm. It forms a hydrate with 4 molecules of water of crystallisation.