Zinc diphosphate

Structural formula
General
Surname	Zinc diphosphate
other names	Zinc pyrophosphate
Molecular formula	Zn 2 P 2 O 7
Brief description	colorless solid
External identifiers / databases
EC number	231-203-4
ECHA InfoCard	100.028.367
PubChem	62641
Wikidata	Q3560487
properties
Molar mass	304.72 g mol −1
Physical state	firmly
density	3.75 g cm −3
Melting point	980 ° C
solubility	practically insoluble in water; soluble in acids, alkalis and aqueous ammonia;
Refractive index	1.633
safety instructions
GHS labeling of hazardous substances
H and P phrases	H: 410
	P: ?
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Zinc diphosphate is an inorganic chemical compound of zinc from the group of diphosphates .

Extraction and presentation

Zinc diphosphate can be obtained by thermal decomposition of ammonium zinc phosphate .

{\ displaystyle \ mathrm {2 \ ZnNH_ {4} PO_ {4} \ longrightarrow Zn_ {2} P_ {2} O_ {7} +2 \ NH_ {3} + H_ {2} O}}

It can also be obtained by reacting sodium carbonate , zinc oxide and ammonium dihydrogen phosphate .

It can also be represented by heating a strongly acetic acid solution of zinc sulfate with sodium pyrophosphate .

{\ displaystyle \ mathrm {2 \ ZnSO_ {4} + Na_ {4} P_ {2} O_ {7} \ longrightarrow Zn_ {2} P_ {2} O_ {7} +2 \ Na_ {2} SO_ {4} }}

properties

Zinc diphosphate is a crystalline colorless solid that is practically insoluble in water. When heated in water, it decomposes into Zn ₃ (PO ₄ ) ₂ and ZnHPO ₄ . It has a monoclinic crystal structure with the space group I 2 / c (space group no. 15, position 6) with a structure similar to thortveitite. At higher temperatures (T> 408 K) it first goes into an intermediate phase α ₂ with the space group C 2 / m (space group no.12) and from 500 K into the β aristotype also with the space group C 2 / m (space groups No. 12) above. Hydrates with 2, 3, 4 and 5 parts of water of crystallization are also known of the compound. The pentahydrate converts to the trihydrate from 358 K and this in turn from 410 K to the anhydrate. The pentahydrate has an orthorhombic crystal structure with the space group Pmmm (space group no. 47) . Template: room group / 15.6 Template: room group / 12 Template: room group / 12 Template: room group / 47

use

Zinc diphosphate is used as a pigment . It can also be used for the gravimetric determination of zinc.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Entry on zinc pyrophosphate in the GESTIS substance database of the IFA , accessed on January 9, 2019(JavaScript required) .
↑ ^a ^b A. Durif: Crystal Chemistry of Condensed Phosphates . Springer Science & Business Media, 2013, ISBN 978-1-4757-9894-4 , pp. 28 ( limited preview in Google Book search).
^ ^A ^b R. Blachnik: Pocket book for chemists and physicists Volume 3: Elements, inorganic compounds and materials, minerals . Springer-Verlag, 2013, ISBN 978-3-642-58842-6 ( limited preview in the Google book search).
↑ MA Petrova, VI Shitova, GA Mikirticheva, VF Popova, AE Malshikov: New data on Zn2P2O7 phase transformations. In: Journal of Solid State Chemistry. 119, 1995, p. 219, doi : 10.1016 / 0022-4596 (95) 80035-N .
↑ Crispin Calvo: THE CRYSTAL STRUCTURE AND PHASE TRANSITIONS OF β-Zn2P2O7. In: Canadian Journal of Chemistry. 43, 1965, p. 1147, doi : 10.1139 / v65-152 .
↑ A. Jarboui, A. Ben Rhaeim, F. Hlel, K. Guidara, M. Gargouri: NMR study and electrical properties investigation of Zn2P2O7. In: Ionics. 16, 2010, p. 67, doi : 10.1007 / s11581-009-0333-5 .
↑ Rudolf Ochs: Practical training in qualitative analysis for chemists · pharmacists and physicians . Springer-Verlag, 2013, ISBN 978-3-662-28315-8 , pp. 117 ( limited preview in Google Book search).
↑ Stöger B., Weil M., Dušek M .: The α ↔ β phase transitions of Zn2P2O7 revisited: existence of an additional intermediate phase with an incommensurately modulated structure . In: Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials . tape 70 , no. 3 , June 1, 2014, doi : 10.1107 / s205252061401049x .
^ Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . CRC Press, 2016, ISBN 978-1-4398-1462-8 , pp. 469 ( limited preview in Google Book search).
^ Arnold F. Holleman, Egon Wiberg: Textbook of inorganic chemistry . de Gruyter, 1995, ISBN 978-3-11-012641-9 , pp. 1493 ( limited preview in Google Book Search).

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f Entry on zinc pyrophosphate in the GESTIS substance database of the IFA , accessed on January 9, 2019(JavaScript required) .

[A._Durif-2] A. Durif: Crystal Chemistry of Condensed Phosphates . Springer Science & Business Media, 2013, ISBN 978-1-4757-9894-4 , pp. 28 ( limited preview in Google Book search).

[R._Blachnik-3] A ^b R. Blachnik: Pocket book for chemists and physicists Volume 3: Elements, inorganic compounds and materials, minerals . Springer-Verlag, 2013, ISBN 978-3-642-58842-6 ( limited preview in the Google book search).

[DOI10.1016/0022-4596(95)80035-N-4] MA Petrova, VI Shitova, GA Mikirticheva, VF Popova, AE Malshikov: New data on Zn2P2O7 phase transformations. In: Journal of Solid State Chemistry. 119, 1995, p. 219, doi : 10.1016 / 0022-4596 (95) 80035-N .

[DOI10.1139/v65-152-5] Crispin Calvo: THE CRYSTAL STRUCTURE AND PHASE TRANSITIONS OF β-Zn2P2O7. In: Canadian Journal of Chemistry. 43, 1965, p. 1147, doi : 10.1139 / v65-152 .

[DOI10.1007/s11581-009-0333-5-6] A. Jarboui, A. Ben Rhaeim, F. Hlel, K. Guidara, M. Gargouri: NMR study and electrical properties investigation of Zn2P2O7. In: Ionics. 16, 2010, p. 67, doi : 10.1007 / s11581-009-0333-5 .

[Rudolf_Ochs-7] Rudolf Ochs: Practical training in qualitative analysis for chemists · pharmacists and physicians . Springer-Verlag, 2013, ISBN 978-3-662-28315-8 , pp. 117 ( limited preview in Google Book search).

[8] Stöger B., Weil M., Dušek M .: The α ↔ β phase transitions of Zn2P2O7 revisited: existence of an additional intermediate phase with an incommensurately modulated structure . In: Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials . tape 70 , no. 3 , June 1, 2014, doi : 10.1107 / s205252061401049x .

[Dale_L._Perry-9] Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . CRC Press, 2016, ISBN 978-1-4398-1462-8 , pp. 469 ( limited preview in Google Book search).

[Arnold_F._Holleman,_Egon_Wiberg-10] Arnold F. Holleman, Egon Wiberg: Textbook of inorganic chemistry . de Gruyter, 1995, ISBN 978-3-11-012641-9 , pp. 1493 ( limited preview in Google Book Search).