Arsenous acid

Arsenous acid
Names
	IUPAC name Arsorous acid
	Other names Arsenious acid; Arsenic oxide
Identifiers
CAS Number	13464-58-9 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:49900 ;
ChemSpider	530 ;
DrugBank	DB04456 ;
PubChem CID	545;
UNII	935XD1L5K2 ;
CompTox Dashboard (EPA)	DTXSID7074828 ;
	InChI InChI=1S/AsH3O3/c2-1(3)4/h2-4H Key: GCPXMJHSNVMWNM-UHFFFAOYSA-N ; InChI=1/AsH3O3/c2-1(3)4/h2-4H Key: GCPXMJHSNVMWNM-UHFFFAOYAA;
	SMILES O[As](O)O;
Properties
Chemical formula	H3AsO3
Molar mass	125.94 g/mol
Appearance	Only exists in aqueous solutions
Conjugate base	Arsenite
Magnetic susceptibility (χ)	-51.2·10−6 cm3/mol
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Toxic, corrosive
	NIOSH (US health exposure limits):
PEL (Permissible)	[1910.1018] TWA 0.010 mg/m3
REL (Recommended)	Ca C 0.002 mg/m3 [15-minute]
IDLH (Immediate danger)	Ca [5 mg/m3 (as As)]
Related compounds
Related compounds	Arsenic acid
	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

Arsenous acid (or arsorous acid) is the inorganic compound with the formula H₃AsO₃, more descriptively written as As(OH)₃. It is an acid known to occur in aqueous solutions. It has not been isolated as a pure material, although this fact does not detract from its significance.