Dimagnesium phosphate

{{About|Dimagnesium phosphate||magnesium phosphate}}

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| Verifiedfields = changed

| verifiedrevid = 446246173

| ImageFile = Magnesium phosphate dibasic.png

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| IUPACName =

| OtherNames = Magnesium hydrogen phosphate; Magnesium phosphate dibasic

| Section1 = {{Chembox Identifiers

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 7757-86-0

| CASNo2_Ref = {{cascite|correct|CAS}}

| CASNo2 = 7782-75-4

| CASNo2_Comment = (trihydrate)

| PubChem = 123955

| EC_number = 231-823-5

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = A1Y870209Z

| UNII1_Ref = {{fdacite|correct|FDA}}

| UNII1 = HF539G9L3Q

| UNII1_Comment = (trihydrate)

| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}

| ChemSpiderID = 110477

| StdInChI_Ref = {{stdinchicite|changed|chemspider}}

| StdInChI = 1S/Mg.H3O4P/c;1-5(2,3)4/h;(H3,1,2,3,4)/q+2;/p-2

| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}

| StdInChIKey = MHJAJDCZWVHCPF-UHFFFAOYSA-L

| SMILES = O=P([O-])(O)[O-].[Mg+2]

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| Section2 = {{Chembox Properties

| Mg = 1 | P = 1 | H = 1 | O = 4

| Appearance =

| Density = 2.13 g/cm3 trihydrate

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| Section3 = {{Chembox Hazards

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| NFPA-H = 0

| NFPA-F = 0

| NFPA-R = 0

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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.{{cite book|author1=Klaus Schrödter|author2=Gerhard Bettermann|author3=Thomas Staffel|author4=Friedrich Wahl|author5=Thomas Klein|author6=Thomas Hofmann|title=Ullmann's Encyclopedia of Industrial Chemistry|chapter=Phosphoric acid and phosphates|series=Ullmann’s Encyclopedia of Industrial Chemistry|year=2008|publisher=Wiley-VCH|place=Weinheim|doi=10.1002/14356007.a19_465.pub3|isbn=978-3527306732|s2cid=94458523 }}

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.Relevant part of the German “[http://www.gesetze-im-internet.de/zzulv_1998/anlage_4_16.html Zusatzstoff-Zulassungsverordnung] {{Webarchive|url=https://web.archive.org/web/20120518144419/http://www.gesetze-im-internet.de/zzulv_1998/anlage_4_16.html |date=2012-05-18 }}”, the official German implementation of the respective regulation of the European Union