Potassium tetrafluoroborate
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| IUPAC name Potassium tetrafluoroborate | |
| Other names Potassium borofluoride Potassium tetrafluoridoborate Borate(1-), tetrafluoro-, potassium (1:1) | |
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| ECHA InfoCard | 100.034.466 |
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| Properties | |
| K[BF4] | |
| Molar mass | 125.90 g·mol−1 |
| Appearance | white crystalline powder |
| Odor | odorless |
| Density | 2.5 g/mL |
| Melting point | 529.5 °C (985.1 °F; 802.6 K) |
| Boiling point | decomposes |
| 0.45g/100g | |
| Solubility in boiling alcohol | sightly soluble |
| Related compounds | |
Other anions | Potassium tetrahydroborate |
Other cations | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
Potassium tetrafluoroborate is an inorganic compound with the formula KBF4. It is a white, odorless crystalline powder, and crystallizes into orthorhombic space group Pbnm.[1]
Potassium tetrafluoroborate has been reacted with molten lithium chloride, sodium chloride, and potassium chloride.[2] Lithium ions cause the decomposition of tetrafluoroborate leading to the production of BCl3 gas. The other liquid alkali chlorides do not decompose the tetrafluoroborate, even though they are at higher temperatures.[2]
Preparation
Potassium fluoroborate is obtained by treating potassium carbonate with boric acid and hydrofluoric acid.
- B(OH)3 + 4 HF → HBF4 + 3 H2O
- 2 HBF4 + K2CO3 → 2 KBF4 + H2CO3
References
- ^ Clark, M. J. R.; Lynton, H. (July 1969). "Crystal structures of potassium, ammonium, rubidium, and cesium tetrafluoborates". Canadian Journal of Chemistry. 47 (14): 2579–2586. doi:10.1139/v69-426. Retrieved 29 July 2025.
- ^ a b Danek, V.; Votava, I.; Matiasovsky, K. (1976). "Reactions of potassium tetrafluoroborate in molten alkali chlorides" (PDF). Chem. Zvesti. 30 (3): 377–383. Retrieved 29 July 2025.
