Fluorosulfuric acid

Fluorosulfuric acid
Names
	IUPAC name Sulfurofluoridic acid
	Systematic IUPAC name Fluorosulfuric acid
	Other names Fluorosulfonic acid,; Fluorosulphonic acid,; Fluorinesulfonic acid,; Fluorinesulphonic acid,; Fluoridosulfonic acid,; Fluoridosulphonic acid,; Sulfuric fluorohydrin, ; Epoxysulfonyl fluoride
Identifiers
CAS Number	7789-21-1 ;
3D model (JSmol)	Interactive image; Interactive image;
ChemSpider	23005 ;
ECHA InfoCard	100.029.227
EC Number	232-149-4;
MeSH	Fluorosulfonic+acid
PubChem CID	24603;
RTECS number	LP0715000;
UNII	PPX0648643 ;
UN number	1777
CompTox Dashboard (EPA)	DTXSID3033511 ;
	InChI InChI=1S/FHO3S/c1-5(2,3)4/h(H,2,3,4) Key: UQSQSQZYBQSBJZ-UHFFFAOYSA-N ; InChI=1/FHO3S/c1-5(2,3)4/h(H,2,3,4) Key: UQSQSQZYBQSBJZ-UHFFFAOYAW;
	SMILES OS(F)(=O)=O; FS(=O)(=O)O;
Properties
Chemical formula	FHO3S
Molar mass	100.06 g·mol−1
Appearance	Colorless liquid
Density	1.726 g cm−3
Melting point	−87.5 °C; −125.4 °F; 185.7 K
Boiling point	165.4 °C; 329.6 °F; 438.5 K
Acidity (pKa)	−10
Conjugate base	Fluorosulfate
Structure
Coordination geometry	Tetragonal at S
Molecular shape	Tetrahedral at S
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314, H332
Precautionary statements	P261, P271, P280, P303+P361+P353, P304+P340+P310, P305+P351+P338
NFPA 704 (fire diamond)	4 0 3 W; OX
Safety data sheet (SDS)	ICSC 0996
Related compounds
Related compounds	Antimony pentafluoride; Trifluoromethanesulfonic acid; Hydrofluoric acid; Sulfurous acid; Sulfuric acid; Sulfur hexafluoride
	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

Fluorosulfuric acid (IUPAC name: sulfurofluoridic acid) is the inorganic compound with the chemical formula HSO₃F. It is one of the strongest acids commercially available. It is a tetrahedral molecule and is closely related to sulfuric acid, H₂SO₄, substituting a fluorine atom for one of the hydroxyl groups. It is a colourless liquid, although commercial samples are often yellow.