Praseodymium (III) sulfate

Structural formula
${\displaystyle \mathrm {\ {\Biggl [}} }$ ${\displaystyle \mathrm {\ \!\ {\Biggr ]}_{2}} }$ ${\displaystyle \mathrm {\ {\Biggl [}} }$ ${\displaystyle \mathrm {\ \!\ {\Biggr ]}_{3}} }$
General
Surname	Praseodymium (III) sulfate
other names	Praseodymium sulfate
Molecular formula	Pr 2 (SO 4 ) 3 Pr 2 (SO 4 ) 3 · n H 2 O, n = 5; 8
Brief description	green monoclinic crystals
External identifiers / databases
CAS number 10277-44-8 (anhydrous) 13510-41-3 (octahydrate) PubChem 165851 Wikidata Q408825
properties
Molar mass	570.00 g mol −1 714.15 g mol −1 (octahydrate)
Physical state	firmly
density	2.83 g cm −3 (octahydrate)
solubility	soluble in water, 170 g l −1 (20 ° C) (octahydrate)
safety instructions
GHS hazard labeling no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Praseodymium (III) sulfate (Pr ₂ (SO ₄ ) ₃ ) is a salt of the rare earth metal praseodymium with sulfuric acid . As an octahydrate, it forms green monoclinic crystals.

presentation

Praseodymium (III) sulfate octahydrate

Crystals of the octahydrate can be grown from solutions obtained by dissolving moistened Pr ₂ O ₃ powder with sulfuric acid. This process can be optimized by evaporation or dissolution steps with the participation of methanol and small amounts of 2,2'-bipyridine .

properties

Praseodymium (III) sulfate is stable under normal conditions. At elevated temperatures it gradually loses its water of crystallization , becoming pale and finally colorless as anhydrous Pr ₂ (SO ₄ ) ₃ .

The octahydrate crystallizes monoclinically in the space group C 2 / c (space group no. 15) with the lattice parameters a  = 1370  pm , b  = 686 pm, c  = 1845 pm and β  = 102.8 ° as well as four formula units per unit cell . Like all rare earth metal sulfates, praseodymium sulfate is less soluble in hot water than in cold water. When a saturated solution is heated, a part crystallizes out.

A pentahydrate is also known.

Individual evidence

1. ↑ ^{a b c d} David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Properties of the Elements and Inorganic Compounds, pp. 4-84.
2. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
3. ↑ ^{a b} Y.-Q. Zheng, Y.-J. Zhu and J.-L. Lin: Redeterminaton of the crystal structure of praseodymium sulfate octahydrate, Pr ₂ (SO ₄ ) ₃  · 8H ₂ O . In: Journal of Crystallography - New Crystal Structures . 217, 2002, pp. 299-300. pdf doi : 10.1524 / ncrs.2002.217.jg.299
4. ^ National Research Council (US): Bulletin of the National Research Council , 1919, National Academies, p. 97 ( limited preview in Google Book Search).