Rubidium perchlorate
Crystal structure | ||||||||||||||||
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__ Rb + __ Cl 7+ __ O 2− | ||||||||||||||||
Crystal system |
orthorhombic |
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Space group |
Pnma (No. 62) |
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Lattice parameters |
a = 749.0 pm, b = 926.9 pm, c = 581.4 pm, Z = 4 |
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General | ||||||||||||||||
Surname | Rubidium perchlorate | |||||||||||||||
Ratio formula | RbClO 4 | |||||||||||||||
Brief description |
white, odorless, hygroscopic crystals |
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External identifiers / databases | ||||||||||||||||
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properties | ||||||||||||||||
Molar mass | 184.92 g · mol -1 | |||||||||||||||
Physical state |
firmly |
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density |
2.8 g cm −3 |
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Melting point |
192 ° C |
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solubility |
poor in water (10.9 g l −1 at 21.3 ° C, 180 g l −1 at 100 ° C) |
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safety instructions | ||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Rubidium perchlorate is the rubidium salt of perchloric acid .
Manufacturing
Rubidium perchlorate can be produced by carefully heating a rubidium chlorate solution, the rubidium chlorate then disproportionates to rubidium perchlorate and rubidium chloride . This releases oxygen .
Rubidium perchlorate can also be obtained by chemical oxidation of rubidium chlorate by mixing aqueous rubidium chlorate solutions with strong oxidizing agents such as e.g. B. converts potassium permanganate and suitable catalysts . The easiest way is to react or neutralize a rubidium carbonate or rubidium hydroxide solution with perchloric acid :
properties
Physical Properties
The solubility of rubidium perchlorate in water increases with increasing temperature and is shown in the table below.
Solubility of RbClO 4 in Water Temperature [° C] 0 10 20th 25th 30th 40 50 60 70 80 90 100 Solubility [g / l] 5 6th 10 12 15th 23 35 48.5 67.2 92 127 180
Rubidium perchlorate is also almost insoluble in common organic solvents:
Solubility of RbClO 4 in organic solvents
(given in g RbClO 4 in 100 g saturated solution at 25 ° C)Methanol 0.060 Ethanol 0.009 n-propanol 0.006 n-butanol 0.002 Isobutanol 0.004 acetone 0.095 Ethyl acetate 0.0016
Rubidium perchlorate crystallizes in the orthorhombic crystal system in the space group Pbnm (space group no.62 , position 3) with the lattice parameters a = 749.0 pm, b = 926.9 pm and c = 581.4 pm, in the unit cell there are four formula units . At 279 ° C there is a phase transformation into a cubic crystal structure with a = 770 pm, in which four formula units are also arranged per unit cell. The crystals are isomorphic to the crystals of potassium perchlorate .
Chemical properties
When heated to red heat, rubidium perchlorate decomposes into rubidium chloride and oxygen.
use
Due to its poor solubility, rubidium perchlorate can be used in addition to rubidium hexachloridoplatinate , rubidium hexafluoridosilicate and rubdium tetrafluoridoborate for the analytical separation of rubidium and potassium .
Individual evidence
- ↑ a b c d e f Jean D'Ans, Ellen Lax: Pocket book for chemists and physicists. 3. Elements, inorganic compounds and materials, minerals, Volume 3. 4. Edition, Springer, 1997, ISBN 978-3-5406-0035-0 , p. 686 ( limited preview in the Google book search).
- ↑ a b Data sheet rubidium perchlorate from AlfaAesar, accessed on June 18, 2010 ( PDF )(JavaScript required) .
- ↑ Data sheet Rubidium perchlorate, anhydrous (PDF) from Strem, accessed on December 25, 2012.
- ↑ a b c R. Abegg, F. Auerbach: Handbuch der inorganic Chemie , Verlag S. Hirzel, Vol. 2, 1908. P. 431; Full text .
- ↑ a b data sheet Rubidium perchlorate from Sigma-Aldrich , accessed on April 22, 2011 ( PDF ).
- ↑ Aterton Seidell: Solubilities Of Organic Compounds Vol - I , p. 1435; Full text .
- ^ KA Hofmann: Textbook of Inorganic Chemistry , 2nd edition 1919. Verlag F. Vieweg & Sohn, p. 439; Full text .