Sodium tetrafluoroborate
Chemical compound
From Wikipedia, the free encyclopedia
Sodium tetrafluoroborate is an inorganic compound with formula NaBF4. It is a salt that forms colorless or white rhombic crystals.[1]
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Other names
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| Identifiers | |||
3D model (JSmol) |
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| ChemSpider | |||
| ECHA InfoCard | 100.033.931 | ||
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PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |||
| NaBF4 | |||
| Molar mass | 109.79 g·mol−1 | ||
| Density | 2.47 g/cm3 | ||
| Melting point | 384 °C (723 °F; 657 K) | ||
| 108 g/100mL[1] | |||
| Hazards | |||
| GHS labelling:[2] | |||
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| Danger | |||
| H314 | |||
| P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340+P310, P305+P351+P338+P310, P363, P405, P501 | |||
| NFPA 704 (fire diamond) | |||
Threshold limit value (TLV) |
2.5 mg/m3[3] (TWA) | ||
| NIOSH (US health exposure limits):[3] | |||
PEL (Permissible) |
2.5 mg/m3 (TWA) | ||
REL (Recommended) |
5 mg/m3 (TWA) | ||
IDLH (Immediate danger) |
250 mg/m3 | ||
| Related compounds | |||
Other cations |
Nitrosonium tetrafluoroborate | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium tetrafluoroborate is used in some fluxes used for brazing[citation needed] and to produce boron trifluoride.[4]
Preparation
Sodium tetrafluoroborate can be prepared by neutralizing tetrafluoroboric acid with sodium carbonate or sodium hydroxide.[5]
- NaOH + HBF4 → NaBF4 + H2O
- Na2CO3 + 2 HBF4 → 2 NaBF4 + H2O + CO2
Alternatively the chemical can be synthesized from boric acid, hydrofluoric acid, and sodium carbonate:[4]
- 2H3BO3 + 8HF + Na2CO3 → 2NaBF4 + 7H2O + CO2
Reactions and uses
On heating to its melting point, sodium tetrafluoroborate decomposes to sodium fluoride (NaF) and boron trifluoride (BF3):[6]
- NaBF4 → NaF + BF3
It is a source of tetrafluoroborate anion, which is used in organic chemistry for the preparation of salts. Sodium tetrafluoroborate can be used for synthesis of ionic liquids, where tetrafluoroborate is the anion.[citation needed]