Hydroxylamine

Hydroxylamine
Names
	IUPAC name Azinous acid
	Preferred IUPAC name Hydroxylamine (only preselected)
	Other names Aminol; Azanol; Hydroxyammonia; Hydroxyamine; Hydroxyazane; Hydroxylazane; Nitrinous acid;
Identifiers
CAS Number	7803-49-8 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:15429 ;
ChEMBL	ChEMBL1191361 ;
ChemSpider	766 ;
ECHA InfoCard	100.029.327
EC Number	232-259-2;
Gmelin Reference	478
KEGG	C00192 ;
MeSH	Hydroxylamine
PubChem CID	787;
RTECS number	NC2975000;
UNII	2FP81O2L9Z ;
CompTox Dashboard (EPA)	DTXSID7041043 ;
	InChI InChI=1S/H3NO/c1-2/h2H,1H2 Key: AVXURJPOCDRRFD-UHFFFAOYSA-N ; InChI=1/H3NO/c1-2/h2H,1H2 Key: AVXURJPOCDRRFD-UHFFFAOYAD;
	SMILES NO;
Properties
Chemical formula	NH2OH
Molar mass	33.030 g·mol−1
Appearance	Vivid white, opaque crystals
Density	1.21 g cm−3 (at 20 °C)
Melting point	33 °C (91 °F; 306 K)
Boiling point	58 °C (136 °F; 331 K) /22 mm Hg (decomposes)
Solubility in water	Soluble
log P	−0.758
Acidity (pKa)	6.03 ([NH3OH]+)
Basicity (pKb)	7.97
Structure
Coordination geometry	Tricoordinated at N, dicoordinated at O
Molecular shape	Trigonal pyramidal at N, bent at O
Dipole moment	0.67553 D
Thermochemistry
Heat capacity (C)	46.47 J/(K·mol)
Std molar; entropy (S⦵298)	236.18 J/(K·mol)
Std enthalpy of; formation (ΔfH⦵298)	−39.9 kJ/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H200, H290, H302, H312, H315, H317, H318, H335, H351, H373, H400
Precautionary statements	P201, P202, P234, P260, P264, P270, P271, P272, P273, P280, P281, P301+P312, P302+P352, P304+P340, P305+P351+P338, P308+P313, P310, P312, P314, P321, P322, P330, P332+P313, P333+P313, P362, P363, P372, P373, P380, P390, P391, P401, P403+P233, P404, P405, P501 Preview warning: Omit Rules: keep P260, omit P261
NFPA 704 (fire diamond)	2 1 3
Flash point	129 °C (264 °F; 402 K)
Autoignition; temperature	265 °C (509 °F; 538 K)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	408 mg/kg (oral, mouse); 59–70 mg/kg (intraperitoneal mouse, rat); 29 mg/kg (subcutaneous, rat)
Safety data sheet (SDS)	ICSC 0661
Related compounds
Related hydroxylammonium salts	Hydroxylammonium chloride; Hydroxylammonium nitrate; Hydroxylammonium sulfate;
Related compounds	Ammonia; Water; Hydrazine; Hydrogen peroxide; N,O-Dimethylhydroxylamine; N,N-Diethylhydroxylamine; Hydroxylamine-O-sulfonic acid; Hydroxylphosphine;
	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

Hydroxylamine (also known as hydroxyammonia) is an inorganic compound with the chemical formula N H₂OH. The compound exists as hygroscopic colorless crystals. Hydroxylamine is almost always provided and used as either an aqueous solution or, more often, as one of its salts, such as hydroxylammonium sulfate, a water-soluble solid.

Hydroxylamine and its salts are consumed almost exclusively to produce Nylon-6. The oxidation of NH₃ to hydroxylamine is a step in biological nitrification.