Rubidium fluoride
| Names | |
|---|---|
| Other names
Rubidium(I) Fluoride
| |
| Identifiers | |
3D model (JSmol)
|
|
| ChemSpider | |
| ECHA InfoCard | 100.033.262 |
PubChem CID
|
|
| RTECS number |
|
| UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
| Properties | |
| RbF | |
| Molar mass | 104.4662 g/mol |
| Appearance | white crystalline solid |
| Density | 3.557 g/cm3 |
| Melting point | 795 °C (1,463 °F; 1,068 K) |
| Boiling point | 1,408 °C (2,566 °F; 1,681 K) |
| 130.6 g/100 mL (18 °C) | |
| Solubility in acetone | 0.0036 g/kg (18 °C)[1] 0.0039 g/kg (37 °C)[1] |
| −31.9·10−6 cm3/mol | |
Refractive index (nD)
|
1.398[2] |
| Structure[2] | |
| Fm3m (No. 225) | |
a = 565 pm
| |
Formula units (Z)
|
4 |
| Thermochemistry[3] | |
Std molar
entropy (S⦵298) |
113.9 J·mol-1·K-1 |
Std enthalpy of
formation (ΔfH⦵298) |
−552.2 kJ/mol |
Gibbs free energy (ΔfG⦵)
|
−520.4 kJ/mol |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards
|
Toxic |
| GHS labelling:[4] | |
| Danger | |
| H301, H302, H311, H312, H315, H319, H331, H332, H335, H351 | |
| P203, P261, P262, P264, P264+P265, P270, P271, P280, P301+P316, P301+P317, P302+P352, P304+P340, P305+P351+P338, P316, P317, P318, P319, P321, P330, P332+P317, P337+P317, P361+P364, P362+P364, P403+P233, P405, P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
Threshold limit value (TLV)
|
2.5 mg/m3, as F |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
|
2.5 mg/m3, as F |
| Related compounds | |
Other anions
|
Rubidium chloride Rubidium bromide Rubidium iodide Rubidium astatide |
Other cations
|
Lithium fluoride Sodium fluoride Potassium fluoride Caesium fluoride Francium fluoride |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
| |
Rubidium fluoride (RbF) is the fluoride salt of rubidium. It is a white crystalline solid with a cubic crystal structure, similar to common salt. It forms two different hydrates, a sesquihydrate with the stoichiometric composition 2RbF·3H2O and a third hydrate with the composition 3RbF·H2O.[5]
Synthesis
There are several methods for synthesising rubidium fluoride. One involves reacting rubidium hydroxide with hydrofluoric acid:[6]
- RbOH + HF → RbF + H2O
Another method is to neutralize rubidium carbonate with hydrofluoric acid:[6]
- Rb2CO3 + 2HF → 2RbF + H2O + CO2
Another possible method is to react rubidium hydroxide with ammonium fluoride:
- RbOH + NH4F → RbF + H2O + NH3
The least used method due to expense of rubidium metal is to react it directly with fluorine gas, as rubidium reacts violently with halogens:[6]
- 2Rb + F2 → 2RbF
Properties
The enthalpy of solution of rubidium fluoride was determined to be −24.28 kJ/mol.[7]
Rubidium fluoride has a purple or magenta red flame test.
Related compounds
In addition to simple rubidium fluoride, an acidic rubidium fluoride with the molecular formula HRbF2 is also known,[8] which can be produced by reacting rubidium fluoride and hydrogen fluoride.[8] The compounds H2RbF3 and H3RbF4 were also synthesized.[9][8]
References
- ^ a b Aterton Seidell (1940). Solubilities Of Organic Compounds Vol - I. Carnegie-Mellon University Hunt Library, N.Sathyanarayanan. D.Van Nostrand Co.
- ^ a b Ans, Jean d'; Lax, Ellen (1998). Taschenbuch für Chemiker und Physiker (in German). Springer. ISBN 978-3-540-60035-0.
- ^ Dickerson, Richard E. (1988). Prinzipien der Chemie (in German). Walter de Gruyter. ISBN 978-3-11-009969-0.
- ^ PubChem. "Rubidium fluoride". pubchem.ncbi.nlm.nih.gov. Retrieved 2026-01-19.
- ^ texte, Académie des sciences (France) Auteur du (1911-01-01). "Comptes rendus hebdomadaires des séances de l'Académie des sciences / publiés... par MM. les secrétaires perpétuels". Gallica. Retrieved 2023-12-24.
- ^ a b c "WebElements". Archived from the original on 2008-04-18. Retrieved 23 February 2006.
- ^ texte, Académie des sciences (France) Auteur du (1911-01-01). "Comptes rendus hebdomadaires des séances de l'Académie des sciences / publiés... par MM. les secrétaires perpétuels". Gallica. Retrieved 2023-12-24.
- ^ a b c Eggeling, Hans; Meyer, Jullius (1905-08-19). "Über die Fluoride des Rubidiums". Zeitschrift für anorganische Chemie. 46 (1): 174–176. doi:10.1002/zaac.19050460111. ISSN 0863-1778.
- ^ A Text-Book of Inorganic Chemistry. Forgotten Books. ISBN 978-1-4510-0469-4.