 | |
| Names | |
|---|---|
| Other names Rubidium(I) Fluoride | |
| Identifiers | |
| CAS Number | |
| 3D model (JSmol) | |
| ChemSpider | |
| ECHA InfoCard | 100.033.262 
|
| PubChem CID | |
| RTECS number |
|
| UNII | |
| CompTox Dashboard (EPA) | |
InChI
| |
SMILES
| |
| Properties | |
| Chemical formula | RbF |
| Molar mass | 104.4662 g/mol |
| Appearance | white crystalline solid |
| Density | 3.557 g/cm |
| Melting point | 795 °C (1,463 °F; 1,068 K) |
| Boiling point | 1,408 °C (2,566 °F; 1,681 K) |
| Solubility in water | 130.6 g/100 mL (18 °C) |
| Magnetic susceptibility (χ) | −31.9·10 cm/mol |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
| Main hazards | Toxic |
| NFPA 704 (fire diamond) |
 |
| Flash point | Non-flammable |
| 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 , 100 kPa).
 Y verify (what is ?)
Infobox references
| |
Rubidium fluoride (RbF) is the fluoride salt of rubidium. It is a cubic crystal with rock-salt structure.
Synthesis
There are several methods for synthesising rubidium fluoride. One involves reacting rubidium hydroxide with hydrofluoric acid:
- RbOH + HF → RbF + H2O
Another method is to neutralize rubidium carbonate with hydrofluoric acid:
- 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:
- 2Rb + F2 → 2RbF
Properties
Rubidium fluoride is a white crystalline substance with a cubic crystal structure that looks very similar to common salt (NaCl). The crystals belong to the space group Fm3m (space group no. 225) with the lattice parameter a = 565 pm and four formula units per unit cell. The refractive index of the crystals is nD = 1.398. Rubidium fluoride colors a flame (Bunsen burner flame) purple or magenta red (spectral analysis).
Rubidium fluoride forms two different hydrates, a sesquihydrate with the stoichiometric composition 2RbF·3H2O and a third hydrate with the composition 3RbF·H2O.
In addition to simple rubidium fluoride, an acidic rubidium fluoride with the molecular formula HRbF2 is also known, which can be produced by reacting rubidium fluoride and hydrogen fluoride. The compounds H2RbF3 and H3RbF4 were also synthesized.
The solubility in acetone is 0.0036 g/kg at 18 °C and 0.0039 g/kg at 37 °C.
The standard enthalpy of formation of rubidium fluoride is ΔfH298 = −552.2 kJ mol−1, the standard free enthalpy of formation ΔG0 = −520.4 kJ mol−1, and the standard molar entropy S298 = 113.9 J K −1 ·mol−1. The enthalpy of solution of rubidium fluoride was determined to be −24.28 kJ/mol.
References
- ^ "WebElements". Archived from the original on 2008-04-18. Retrieved 23 February 2006.
- ^ Ans, Jean d'; Lax, Ellen (1998). Taschenbuch für Chemiker und Physiker (in German). Springer. ISBN 978-3-540-60035-0.
- 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.
- ^ 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.
- Aterton Seidell (1940). Solubilities Of Organic Compounds Vol - I. Carnegie-Mellon University Hunt Library, N.Sathyanarayanan. D.Van Nostrand Co.
- ^ Dickerson, Richard E. (1988). Prinzipien der Chemie (in German). Walter de Gruyter. ISBN 978-3-11-009969-0.
- 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.
- "Rubidium compounds: rubidium fluoride". WebElements: the periodic table on the web. WebElements. Retrieved 16 November 2011.
| Rubidium compounds | |
|---|---|