Barium phosphate

Structural formula
General
Surname	Barium phosphate
other names	Barium orthophosphate
Molecular formula	Ba 3 (PO 4 ) 2
External identifiers / databases
CAS number 13517-08-3 EC number 236-856-9 ECHA InfoCard 100.033.491 PubChem 165803 Wikidata Q808224
properties
Molar mass	601.9 g · mol -1
Physical state	firmly
density	4.1 g cm −3
Melting point	1605 ° C
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 332-302 P: 305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Barium phosphate (more precisely: barium orthophosphate) is the barium salt of phosphoric acid .

Manufacturing

Bariumorthophosphat may consist Bariumhydrogenphosphat be prepared initially by heating at 900 ° C to Bariumdiphosphat is converted. This reacts with barium carbonate , splitting off carbon dioxide to form barium orthophosphate.

${\displaystyle \mathrm {2\ BaHPO_{4}\ {\xrightarrow {900^{o}C}}\ Ba_{2}P_{2}O_{7}+H_{2}O\uparrow } }$

${\displaystyle \mathrm {Ba_{2}P_{2}O_{7}+BaCO_{3}\ {\xrightarrow {1300^{o}C}}\ Ba_{3}(PO_{4})_{2}+CO_{2}\uparrow } }$

It is also formed when sodium phosphate reacts with barium chloride .

${\displaystyle \mathrm {3\ BaCl_{2}+2\ Na_{3}PO_{4}\ \longrightarrow \ Ba_{3}(PO_{4})_{2}+6\ NaCl} }$

The reaction of disodium hydrogen phosphate with barium chloride in the presence of ammonia has also been described.

${\displaystyle \mathrm {3\ BaCl_{2}+2\ Na_{2}HPO_{4}+2\ NH_{3}\ \longrightarrow } }$

${\displaystyle \mathrm {Ba_{3}(PO_{4})_{2}+4\ NaCl+2\ NH_{4}Cl} }$

properties

Barium orthophosphate exists in two different crystal structures . The phase transition takes place at 1360 ° C. Below the transition point it crystallizes in the trigonal crystal system in the space group R 3 m (space group no. 160) with the lattice parameters a = 7.696  Å and α = 42.58 °. There is a formula unit in the unit cell . The crystals are isomorphic to strontium phosphate .

use

Barium orthophosphate is used as a raw material for the production of special glass (e.g. uviol glass ) and as an opacifier for glass.

Individual evidence

1. ^ Jean D'Ans, Ellen Lax: Pocket book for chemists and physicists. Springer, 1998, ISBN 978-3-540-60035-0 , p. 328 ( limited preview in Google book search).
2. ↑ ^{a b c} E. Radominska, T. Znamierowska, W. Szuszkiewicz: Phase equilibria in the system Rb ₃ PO ₄ -Ba ₃ (PO ₄ ) ₂ . In: Journal of Thermal Analysis and Calorimetry 2011 , 103 (2). Pp. 761-766. doi : 10.1007 / s10973-010-0962-y
3. ↑ Entry on barium salts in the GESTIS substance database of the IFA , accessed on February 1, 2016 (JavaScript required)
4. ↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the indicated labeling it falls under the group entry barium salts, with the exception of barium sulphate, salts of 1-azo-2-hydroxynaphthalenyl aryl sulphonic acid, and of salts specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
5. ↑ Data sheet barium phosphate from Sigma-Aldrich , accessed on February 16, 2020 ( PDF ).
6. ^ M. Berthelot: Recherches sur les phosphates . In: Compt. Rend. Hebd. 1886 , 103 , p. 911.
7. ↑ ^{a b} R. Abegg, F. Auerbach: Handbuch der inorganic Chemie . Verlag S. Hirzel, Vol. 2, 1908. P. 282.
8. ↑ C. Rammelsberg: About the composition of some phosphoric acid salts . In: Pogg. Ann. 1846 , 68 , p. 383ff.
9. ^ ^{A b} W. H. Zachariasen: The Crystal Structure of the Normal Orthophosphates of Barium and Strontium . In: Acta Cryst. 1948 , 1 , pp. 263-265. doi : 10.1107 / S0365110X48000697
10. ↑ State Office of Saxony: Information sheet on glass ( Memento from May 14, 2013 in the Internet Archive )
11. ↑ Federal Customs Administration: Chapter 28: Inorganic Chemical Products; inorganic or organic compounds of precious metals, radioactive elements, rare earth metals or isotopes , accessed on June 17, 2017.