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Zinc pyrophosphate

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-4Key: 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-4Key: OMSYGYSPFZQFFP-XBHQNQODAA
SMILES ..P()(=O)OP()()=O
Properties
Chemical formula	Zn2P2O7
Molar mass	304.72 g/mol
Appearance	White crystalline powder
Density	3.75 g/cm
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 , 100 kPa). N verify (what is  ?) Infobox references

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

Preparation

Zinc pyrophosphate can be obtained from the thermal decomposition of zinc ammonium phosphate.

2 ZnNH₄PO₄ → Zn₂P₂O₇ + 2 NH₃ + H₂O

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

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.

2 ZnSO₄ + Na₄P₂O₇ → Zn₂P₂O₇ + 2 Na₂SO₄

Another method is precipitating zinc as a phosphate, then heating over 1123 K.

Properties

Zinc pyrophosphate is a white crystalline solid that is insoluble in water. 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.

References

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
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.
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.
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.

• Pyrophosphate salts
• Zinc compounds