Sodium tetrafluoroborate

Sodium tetrafluoroborate
The sodium cation	The tetrafluoroborate anion (ball-and-stick model)
Names
	Other names Sodium fluoroborate; Borate(1-), tetrafluoro-, sodium;
Identifiers
CAS Number	13755-29-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	24462 ;
ECHA InfoCard	100.033.931
EC Number	237-340-6;
PubChem CID	4343483;
UNII	CFC805A5WR ;
CompTox Dashboard (EPA)	DTXSID9021477 ;
	InChI InChI=1S/BF4.Na/c2-1(3,4)5;/q-1;+1;
	SMILES [B-](F)(F)(F)F.[Na+];
Properties
Chemical formula	NaBF4
Molar mass	109.79 g·mol−1
Density	2.47 g/cm3
Melting point	384 °C (723 °F; 657 K)
Solubility in water	108 g/100mL
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340+P310, P305+P351+P338+P310, P363, P405, P501
NFPA 704 (fire diamond)	3 0 0
Threshold limit value (TLV)	2.5 mg/m3 (TWA)
	NIOSH (US health exposure limits):
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). verify (what is ?) Infobox references

Sodium tetrafluoroborate is an inorganic compound with formula NaBF₄. It is a salt that forms colorless or white rhombic crystals.^[1]

Sodium tetrafluoroborate is used in some fluxes used for brazing 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.

References

^ ^a ^b Milne, G. W. A (2005-07-11). Gardner's Commercially Important Chemicals: Synonyms, Trade Names, and Properties. John Wiley & Sons. ISBN 9780471735182.
^ ^a ^b ^c "SDS - Sodium tetrafluoroborate". fishersci.com. ThermoFisher Scientific. 26 March 2024. Retrieved 7 November 2025.
^ Sigma-Aldrich Co., Sodium tetrafluoroborate.
^ ^a ^b Kwasnik, W. Brauer, Georg (ed.). Handbook of Preparative Inorganic Chemistry Vol. 1, 2nd Ed. New York: Academic Press. p. 220. ISBN 978-0121266011.
^ Eagleson, Mary (1994). Concise Encyclopedia Chemistry. Walter de Gruyter. ISBN 9783110114515.
^ Lewis Sr., Richard J. (2008-07-14). Hazardous Chemicals Desk Reference. Wiley. ISBN 9780470334454.

[Gardners-1] Milne, G. W. A (2005-07-11). Gardner's Commercially Important Chemicals: Synonyms, Trade Names, and Properties. John Wiley & Sons. ISBN 9780471735182.

[FisherSDS-2] "SDS - Sodium tetrafluoroborate". fishersci.com. ThermoFisher Scientific. 26 March 2024. Retrieved 7 November 2025.

[3] Sigma-Aldrich Co., Sodium tetrafluoroborate.

[Georg-4] Kwasnik, W. Brauer, Georg (ed.). Handbook of Preparative Inorganic Chemistry Vol. 1, 2nd Ed. New York: Academic Press. p. 220. ISBN 978-0121266011.

[concise-5] Eagleson, Mary (1994). Concise Encyclopedia Chemistry. Walter de Gruyter. ISBN 9783110114515.

[6] Lewis Sr., Richard J. (2008-07-14). Hazardous Chemicals Desk Reference. Wiley. ISBN 9780470334454.

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