Hydroiodic acid

Hydroiodic acid
Names
	Other names Aqueous hydrogen iodide; Hydriodic acid; Hydrogen iodide, hydrous; Hydronium iodide;
Identifiers
CAS Number	10034-85-2 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:43451 ;
ChemSpider	23224 ;
EC Number	233-109-9;
PubChem CID	24841;
RTECS number	MW3760000;
UNII	694C0EFT9Q ;
	InChI InChI=1S/BrH/h1H Key: CPELXLSAUQHCOX-UHFFFAOYSA-N ; InChI=1/BrH/h1H Key: CPELXLSAUQHCOX-UHFFFAOYAZ;
	SMILES [OH3+].[I-];
Properties
Chemical formula	HI(aq)
Molar mass	127.912 g·mol−1 (HI)
Appearance	colorless liquid
Odor	acrid
Density	1.70 g/mL, azeotrope; (57% HI by weight)
Boiling point	127 °C (261 °F; 400 K) 1.03 bar, azeotrope
Solubility in water	Aqueous solution
Acidity (pKa)	−9.3 (HI)
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, P501
NFPA 704 (fire diamond)	3 0 0 ACID
Flash point	Non-flammable
Related compounds
Other anions	Hydrofluoric acid; Hydrochloric acid; Hydrobromic acid;
Related compounds	Hydrogen iodide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Hydroiodic acid (or hydriodic acid) is a colorless liquid. It is an aqueous solution of hydrogen iodide with the chemical formula H I(aq). It is a strong acid, in which hydrogen iodide is ionized completely in an aqueous solution. Concentrated aqueous solutions of hydrogen iodide are usually 48% to 57% HI by mass.