Sodium tetrafluoroborate

Sodium tetrafluoroborate is an inorganic compound with formula NaBF₄. It is a salt that forms colorless or white rhombic crystals and is soluble in water (108 g/100 mL) but less soluble in organic solvents.^[1]

Sodium tetrafluoroborate

The sodium cation The tetrafluoroborate anion (ball-and-stick model)
Names
Other names sodium fluoroborate, NaBF4
Identifiers
CAS Number	13755-29-8 Y
3D model (JSmol)	Interactive image
ChemSpider	24462 N
ECHA InfoCard	100.033.931
PubChem CID	4343483
UNII	CFC805A5WR Y
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	109.794 g/mol
Density	2.47 g/cm3
Melting point	384 °C (723 °F; 657 K)
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). N verify (what is YN ?) Infobox references

Sodium tetrafluoroborate is used in some fluxes used for brazing and to produce boron trifluoride.^[2]

Preparation

Sodium tetrafluoroborate can be prepared by neutralizing tetrafluoroboric acid with sodium carbonate or sodium hydroxide.^[3]

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:^[2]

2H₃BO₃ + 8HF + Na₂CO₃ → 2NaBF₄ + 7H₂O + CO₂

Reactions and uses

On heating to its melting point, sodium tetrafluoroborate decomposes to sodium fluoride and boron trifluoride:^[4]

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.