Zinc pyrophosphate[ 1]
Names
Other names
Dizinc diphosphate
Identifiers
ChemSpider
ECHA InfoCard
100.028.367
UNII
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
Y Key: OMSYGYSPFZQFFP-UHFFFAOYSA-J
Y 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
[Zn+2].[Zn+2].[O-]P([O-])(=O)OP([O-])([O-])=O
Properties
Zn2 P2 O7
Molar mass
304.72 g/mol
Appearance
White crystalline powder
Density
3.75 g/cm3
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).
Chemical compound
Zinc pyrophosphate (Zn2 P2 O7 ) 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 ZnNH4 PO4 → Zn2 P2 O7 + 2 NH3 + H2 O
It can also be obtained from the reaction between sodium carbonate , zinc oxide , and ammonium dihydrogen phosphate .[ 3]
Na2 CO3 + 2 ZnO + 2 (NH4 )H2 PO4 → Zn2 P2 O7 + 2 NaOH + 2 NH3 + 2 H2 O + CO2
It is also produced when a strongly acidic solution of zinc sulfate is heated with sodium pyrophosphate .[ 4]
2 ZnSO4 + Na4 P2 O7 → Zn2 P2 O7 + 2 Na2 SO4
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 .