Rubidium carbonate

Structural formula
General
Surname	Rubidium carbonate
Molecular formula	Rb 2 CO 3
Brief description	white odorless solid
External identifiers / databases
CAS number 584-09-8 EC number 209-530-9 ECHA InfoCard 100.008.666 PubChem 11431 Wikidata Q424915
properties
Molar mass	230.95 g mol −1
Physical state	firmly
density	3.55 g cm −3
Melting point	837 ° C
solubility	very light in water (4500 g l −1 at 20 ° C) hardly in ethanol
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 315-319-335 P: 261-305 + 351 + 338
Toxicological data	2630 mg kg −1 ( LD 50 ,  rat ,  oral )
Thermodynamic properties
ΔH f 0	−1136.0 kJ / mol
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Rubidium carbonate is a chemical compound from the group of rubidium compounds and carbonates .

Extraction and presentation

Rubidium carbonate can be obtained by reacting ammonium carbonate with rubidium hydroxide.

${\displaystyle \mathrm {(NH_{4})_{2}CO_{3}+2\ RbOH\longrightarrow Rb_{2}CO_{3}+2\ NH_{3}\uparrow +\ 2\ H_{2}O} }$

Another method is the oxidation of rubidium oxalate .

${\displaystyle \mathrm {2\ Rb_{2}C_{2}O_{4}+O_{2}\longrightarrow 2\ Rb_{2}CO_{3}+2\ CO_{2}\uparrow } }$

When processing the mineral lepidolite , a mixture of potassium carbonate, rubidium carbonate and cesium carbonate is obtained.

properties

Physical Properties

Rubidium carbonate is a white, odorless, moisture-sensitive, air-sensitive, hygroscopic solid. It occurs in three crystal modifications, with only the alpha form being present at room temperature. The space groups for the modifications are P 2 ₁ / c (space group no.14 ) with the lattice parameters a = 734.4 pm, b = 1011.6 pm, c = 587.26 pm, as well as four formula units per unit cell , Pnma ( No. 62) and P 6 ₃ / mmc (No. 194) . They therefore correspond to those of potassium and cesium carbonate .

0.74 g of rubidium carbonate dissolve in 100 g of absolute ethanol .

The standard enthalpy of formation of rubidium carbonate is −1150 kJ mol ⁻¹ .

Chemical properties

Rubidium carbonate dissociates above 900 ° C.

${\displaystyle \mathrm {Rb_{2}CO_{3}\longrightarrow Rb_{2}O+CO_{2}} }$

When carbon dioxide is introduced into the aqueous solution, rubidium hydrogen carbonate is formed .

${\displaystyle \mathrm {Rb_{2}CO_{3}+CO_{2}+H_{2}O\longrightarrow 2\ RbHCO_{3}} }$

When heated with magnesium in a hydrogen stream, rubidium hydride is formed .

${\displaystyle \mathrm {Rb_{2}CO_{3}+Mg+H_{2}\ {\xrightarrow {\ \Delta \ }}\ 2\ RbH+MgO+CO_{2}\uparrow } }$

use

Rubidium carbonate is used for the production of special glasses and as a catalyst for the production of short-chain alcohols from natural gas and for the production of other rubidium compounds.

Rubidium carbonate can be used for the analytical separation of rubidium and cesium , since it is hardly soluble in ethanol, but cesium carbonate is readily soluble.

Individual evidence

1. ↑ ^{a b c d e f} Entry on rubidium carbonate in the GESTIS substance database of the IFA , accessed on February 14, 2017(JavaScript required) .
2. ^ ^{A b} Jean D'Ans, Ellen Lax: Paperback for chemists and physicists . 3. Elements, inorganic compounds and materials, minerals . Volume 3. 4th edition. Springer, 1997, ISBN 978-3-540-60035-0 , p. 684 ( limited preview in Google book search).
3. ↑ ^{a b} K. A. Hofmann: Textbook of inorganic chemistry. 2nd edition 1919. Verlag F. Vieweg & Sohn, p. 439 ( Textarchiv - Internet Archive ).
4. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-20.
5. ^ Rubidium . In: Encyclopædia Britannica . 11th edition. tape 23 : Refectory - Sainte-Beuve . London 1911, p. 808 (English, full text [ Wikisource ]).
6. ↑ Sascha Vensky: Conformational elucidation of inorganic oxo anions of carbon and solid-state synthesis by electrocrystallization of Ag ₃ O ₄ and Na ₃ BiO ₄ . Stuttgart 2004, DNB  97181533X , urn : nbn: de: bsz: 93-opus-19129 (dissertation, University of Stuttgart).
7. ↑ Aterton Seidell: Solubilities Of Organic Compounds Vol - I. S. 1432 ( Text archive - Internet Archive ).
8. ↑ Fania Moriseevna Perelman: rubidium and cesium. Verlag Pergamon Press, 1965, p. 46, doi: 10.1002 / anie.19660780727 ( limited preview in the Google book search).
9. ^ Dale L. Perry, Sidney L. Phillips: Handbook of inorganic compounds . CRC Press, 1995, ISBN 978-0-8493-8671-8 , p. 333 ( limited preview in Google book search).
10. ↑ R. Abegg, F. Auerbach: Handbuch der inorganic Chemie . Volume 2. Verlag S. Hirzel, 1908, p. 435 ( Textarchiv - Internet Archive ).
11. ↑ JW Mellor: A comprehensive treatise on inorganic and theoretical chemistry. Volume 2. Verlag Wiley, 1962, p. 2186 ( limited preview in Google book search).
12. ↑ Winfried Lenk, Horst Prinz, Anja Steinmetz: Rubidium and Rubidium Compounds . In: Ullmann's Encyclopedia of Industrial Chemistry . Wiley-VCH Verlag, 2000, ISBN 978-3-527-30673-2 , doi : 10.1002 / 14356007.a23_473.pub2 .
13. ↑ Rubidium carbonate (micronmetals) ( Memento from October 6, 2010 in the Internet Archive )