:Zinc pyrophosphate

{{chembox

| Verifiedfields = changed

| verifiedrevid = 470636803

| Name = Zinc pyrophosphate

| Reference =

{{Citation

| last = Lide

| first = David R.

| year = 1998

| title = Handbook of Chemistry and Physics

| edition = 87

| location = Boca Raton, Florida

| publisher = CRC Press

| isbn = 0-8493-0594-2

| pages = 4–96

}}

| ImageFile = Zinc_pyrophosphate.svg

| ImageSize = 200px

| ImageName = Zinc pyrophosphate

| OtherNames = Dizinc diphosphate

| Section1 = {{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 56393

| PubChem = 62641

| InChI = 1/H4O7P2.2Zn/c1-8(2,3)7-9(4,5)6;;/h(H2,1,2,3)(H2,4,5,6);;/q;2*+2/p-4

| InChIKey = OMSYGYSPFZQFFP-XBHQNQODAA

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

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/H4O7P2.2Zn/c1-8(2,3)7-9(4,5)6;;/h(H2,1,2,3)(H2,4,5,6);;/q;2*+2/p-4

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = OMSYGYSPFZQFFP-UHFFFAOYSA-J

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

| CASNo = 7446-26-6

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

| UNII = 6ERT96A621

}}

| Section2 = {{Chembox Properties

| Formula = Zn2P2O7

| MolarMass = 304.72 g/mol

| Appearance = White crystalline powder

| Density = 3.75 g/cm3

| MeltingPt =

| BoilingPt =

| Solubility = Insoluble

| SolubleOther = Soluble in dilute acids

}}

| Section3 = {{Chembox Structure

| CrystalStruct =

}}

| Section7 = {{Chembox Hazards

| HPhrases =

| PPhrases =

}}

}}

Zinc pyrophosphate (Zn2P2O7) is an ionic inorganic chemical compound composed of Zn2+ cations and pyrophosphate anions.

Preparation

Zinc pyrophosphate can be obtained from the thermal decomposition of zinc ammonium phosphate.{{Cite journal|last=Calvo|first=Crispin|date=1965-05-01|title=THE CRYSTAL STRUCTURE AND PHASE TRANSITIONS OF β-Zn 2 P 2 O 7|journal=Canadian Journal of Chemistry|language=en|volume=43|issue=5|pages=1147–1153|doi=10.1139/v65-152|issn=0008-4042|doi-access=free}}

:2 ZnNH4PO4 → Zn2P2O7 + 2 NH3 + H2O

It can also be obtained from the reaction between sodium carbonate, zinc oxide, and ammonium dihydrogen phosphate.{{Cite journal|last1=Jarboui|first1=A.|last2=Ben Rhaeim|first2=A.|last3=Hlel|first3=F.|last4=Guidara|first4=K|last5=Gargouri|first5=M.|date=2010|title=NMR study and electrical properties investigation of Zn2P2O7|url=http://link.springer.com/10.1007/s11581-009-0333-5|journal=Ionics|language=en|volume=16|issue=1|pages=67–73|doi=10.1007/s11581-009-0333-5|s2cid=94790682 |issn=0947-7047|url-access=subscription}}

:Na2CO3 + 2 ZnO + 2 (NH4)H2PO4 → Zn2P2O7 + 2 NaOH + 2 NH3 + 2 H2O + CO2

It is also produced when a strongly acidic solution of zinc sulfate is heated with sodium pyrophosphate.{{Cite book|last=Ochs|first=Rudolf|url=https://books.google.com/books?id=1hmBBwAAQBAJ&pg=PA117|title=Praktikum der Qualitativen Analyse Für Chemiker · Pharmazeuten und Mediziner|publisher=Springer-Verlag|year=2013|isbn=978-3-662-28315-8|location=Berlin, Heidelberg|pages=117|oclc=860357745}}

:2 ZnSO4 + Na4P2O7 → Zn2P2O7 + 2 Na2SO4

Another method is precipitating zinc as a phosphate, then heating over 1123 K.{{Citation needed|date=May 2009}}

Properties

Zinc pyrophosphate is a white crystalline solid that is insoluble in water.{{Cite book|last=Perry|first=Dale L.|url=https://books.google.com/books?id=SFD30BvPBhoC&pg=PA469|title=Handbook of Inorganic Compounds|publisher=CRC Press|year=2016|isbn=978-1-4398-1462-8|edition=2nd|location=Boca Raton, FL|pages=469|oclc=759865801}} On heating in water, it decomposes to form Zn3(PO4)2 and ZnHPO4. It crystallizes in the monoclinic system. The α-form crystallizes at low temperatures and the β-form crystallizes at high temperatures.

Uses

Zinc pyrophosphate is used as a pigment. It is useful in gravimetric analysis of zinc.{{Cite book|last1=Holleman|first1=Arnold F.|title=Lehrbuch der anorganischen Chemie|last2=Wiberg|first2=Egon|last3=Wiberg|first3=Nils|publisher=de Gruyter|year=1995|isbn=978-3-11-012641-9|edition=102nd|location=Berlin|pages=1493|oclc=237142268}}

References

{{Reflist}}

{{Zinc compounds}}

Category:Pyrophosphate salts

pyrophosphate