Dimagnesium phosphate

This article is about Dimagnesium phosphate. For other uses, see magnesium phosphate.

Dimagnesium phosphate is a compound with formula MgHPO₄. It is a Mg²⁺ salt of monohydrogen phosphate. The trihydrate is well known, occurring as the mineral newberyite.^[1]

Dimagnesium phosphate

Names
Other names Magnesium hydrogen phosphate; Magnesium phosphate dibasic
Identifiers
CAS Number	7757-86-0 Y 7782-75-4 (trihydrate) Y
3D model (JSmol)	Interactive image
ChemSpider	110477 N
ECHA InfoCard	100.028.930
EC Number	231-823-5
E number	E343(ii) (antioxidants, ...)
PubChem CID	123955
UNII	A1Y870209Z Y HF539G9L3Q (trihydrate) Y
CompTox Dashboard (EPA)	DTXSID00872522
InChI InChI=1S/Mg.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+2;/p-2 N Key: MHJAJDCZWVHCPF-UHFFFAOYSA-L N
SMILES O=P([O-])(O)[O-].[Mg+2]
Properties
Chemical formula	HMgO4P
Molar mass	120.283 g·mol−1
Density	2.13 g/cm3 trihydrate
Hazards
NFPA 704 (fire diamond)	0 0 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

It can be formed by reaction of stoichiometric quantities of magnesium oxide with phosphoric acid.

MgO + H₃PO₄ → MgHPO₄ + H₂O

Dissolving monomagnesium phosphate in water, forms phosphoric acid and depositing a solid precipitate of dimagnesium phosphate trihydrate:

Mg(H₂PO₄)₂ + 3 H₂O → Mg(HPO₄)^.3H₂O + H₃PO₄

The compound is used as a nutritional supplement, especially for infants and athletes. Its E number is E343.^[2]

See also

• Magnesium phosphate