Zinc pyrophosphate

Zinc pyrophosphate^[1]
Names
	Other names Dizinc diphosphate
Identifiers
CAS Number	7446-26-6 ;
3D model (JSmol)	Interactive image;
ChemSpider	56393 ;
ECHA InfoCard	100.028.367
PubChem CID	62641;
UNII	6ERT96A621 ;
CompTox Dashboard (EPA)	DTXSID0064705 ;
	InChI InChI=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 Key: OMSYGYSPFZQFFP-UHFFFAOYSA-J ; 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 Key: OMSYGYSPFZQFFP-XBHQNQODAA;
	SMILES [Zn+2].[Zn+2].[O-]P([O-])(=O)OP([O-])([O-])=O;
Properties
Chemical formula	Zn2P2O7
Molar mass	304.72 g/mol
Appearance	White crystalline powder
Density	3.75 g/cm3
Solubility in water	Insoluble
Solubility	Soluble in dilute acids
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

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.^[2]

2 ZnNH₄PO₄ → Zn₂P₂O₇ + 2 NH₃ + H₂O

It can also be obtained from the reaction between sodium carbonate, zinc oxide, and ammonium dihydrogen phosphate.^[3]

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.^[4]

2 ZnSO₄ + Na₄P₂O₇ → Zn₂P₂O₇ + 2 Na₂SO₄

Another method is precipitating zinc as a phosphate, then heating over 1123 K.^{[citation needed]}

Properties

Zinc pyrophosphate is a white crystalline solid that is insoluble in water.^[5] 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.^[2]^[3]

Uses

Zinc pyrophosphate is used as a pigment.^[5] It is useful in gravimetric analysis of zinc.^[6]

References

^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, Florida: CRC Press, pp. 4–96, ISBN 0-8493-0594-2
^ ^a ^b Calvo, Crispin (1965-05-01). "THE CRYSTAL STRUCTURE AND PHASE TRANSITIONS OF β-Zn 2 P 2 O 7". Canadian Journal of Chemistry. 43 (5): 1147–1153. doi:10.1139/v65-152. ISSN 0008-4042.
^ ^a ^b Jarboui, A.; Ben Rhaeim, A.; Hlel, F.; Guidara, K; Gargouri, M. (2010). "NMR study and electrical properties investigation of Zn2P2O7". Ionics. 16 (1): 67–73. doi:10.1007/s11581-009-0333-5. ISSN 0947-7047. S2CID 94790682.
^ Ochs, Rudolf (2013). Praktikum der Qualitativen Analyse Für Chemiker · Pharmazeuten und Mediziner. Berlin, Heidelberg: Springer-Verlag. p. 117. ISBN 978-3-662-28315-8. OCLC 860357745.
^ ^a ^b Perry, Dale L. (2016). Handbook of Inorganic Compounds (2nd ed.). Boca Raton, FL: CRC Press. p. 469. ISBN 978-1-4398-1462-8. OCLC 759865801.
^ Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1995). Lehrbuch der anorganischen Chemie (102nd ed.). Berlin: de Gruyter. p. 1493. ISBN 978-3-11-012641-9. OCLC 237142268.

[hand-1] Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, Florida: CRC Press, pp. 4–96, ISBN 0-8493-0594-2

[Calvo-2] Calvo, Crispin (1965-05-01). "THE CRYSTAL STRUCTURE AND PHASE TRANSITIONS OF β-Zn 2 P 2 O 7". Canadian Journal of Chemistry. 43 (5): 1147–1153. doi:10.1139/v65-152. ISSN 0008-4042.

[Jarboui-3] Jarboui, A.; Ben Rhaeim, A.; Hlel, F.; Guidara, K; Gargouri, M. (2010). "NMR study and electrical properties investigation of Zn2P2O7". Ionics. 16 (1): 67–73. doi:10.1007/s11581-009-0333-5. ISSN 0947-7047. S2CID 94790682.

[4] Ochs, Rudolf (2013). Praktikum der Qualitativen Analyse Für Chemiker · Pharmazeuten und Mediziner. Berlin, Heidelberg: Springer-Verlag. p. 117. ISBN 978-3-662-28315-8. OCLC 860357745.

[Perry-5] Perry, Dale L. (2016). Handbook of Inorganic Compounds (2nd ed.). Boca Raton, FL: CRC Press. p. 469. ISBN 978-1-4398-1462-8. OCLC 759865801.

[6] Holleman, Arnold F.; Wiberg, Egon; Wiberg, Nils (1995). Lehrbuch der anorganischen Chemie (102nd ed.). Berlin: de Gruyter. p. 1493. ISBN 978-3-11-012641-9. OCLC 237142268.

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