1692. Calcium Phosphate, Dibasic

Nomenclature

CAS number: 7757-93-9
Calcium monohydrogen phosphate; dicalcium orthophosphate; secondary calcium phosphate.
CaHO4P; mol wt 136.06.
Ca 29.46%, H 0.74%, O 47.04%, P 22.76%.
CaHPO4.

Description and references

Occurs in nature as the mineral monetite. Prepn from CaCl2 and Na2HPO4: Jensen, Rathley, Inorg. Synth. 4, 19, 20 (1953); from Ca3(PO4)2 and H3PO4: Perloff, Posner, ibid. 6, 16 (1960), where it is an intermediate in the preparation of hydroxyapatite.

Properties

Triclinic crystals. At red heat dehydrated to calcium pyrophosphate. Practically insol in water, alcohol.

Derivative

Dihydrate.

Nomenclature

Brushite.

Properties

Monoclinic crystals. Loses water of crystn slowly below 100°. Dehydr at red heat to calcium pyrophosphate. d 2.31. Practically insol in water, alcohol; sol in dil HCl or HNO3; slightly sol in dil acetic acid.

Use

Chiefly in animal feeds; mineral supplement in cereals and other foods; manuf of glass; in dental products, fertilizers (see also Calcium Phosphate, Monobasic).

Therapeutic Category

Calcium replenisher.

Therapeutic Category (Veterinary)

Has been used as a dietary supplement, and as an antacid.

Keywords

Replenishers/Supplements; Calcium