Ethenone

Ethenone
Names
	Preferred IUPAC name Ethenone
	Other names Ketene; Carbomethene; Keto-ethylene
Identifiers
CAS Number	463-51-4 ;
3D model (JSmol)	Interactive image;
Beilstein Reference	1098282
ChEBI	CHEBI:48003 ;
ChemSpider	9643 ;
ECHA InfoCard	100.006.671
EC Number	207-336-9;
PubChem CID	10038;
RTECS number	OA7700000;
UNII	LEP3SM032A ;
CompTox Dashboard (EPA)	DTXSID1052113 ;
	InChI InChI=1S/C2H2O/c1-2-3/h1H2 Key: CCGKOQOJPYTBIH-UHFFFAOYSA-N ; InChI=1/C2H2O/c1-2-3/h1H2 Key: CCGKOQOJPYTBIH-UHFFFAOYSA-N; InChI=1/C2H2O/c1-2-3/h1H2 Key: CCGKOQOJPYTBIH-UHFFFAOYAO;
	SMILES O=C=C;
Properties
Chemical formula	C2H2O
Molar mass	42.037 g/mol
Appearance	Colourless gas
Odor	penetrating
Density	1.93 g/cm3
Melting point	−150.5 °C (−238.9 °F; 122.6 K)
Boiling point	−56.1 °C (−69.0 °F; 217.1 K)
Solubility in water	decomposes
Solubility	soluble in acetone; ethanol; ethyl ether; aromatic solvents; halocarbons
Vapor pressure	>1 atm (20°C)
Refractive index (nD)	1.4355
Thermochemistry
Heat capacity (C)	51.75 J/K mol
Std enthalpy of; formation (ΔfH⦵298)	−87.24 kJ/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H220, H315, H318, H330, H335
Precautionary statements	P203, P210, P222, P260, P264, P264+P265, P271, P280, P284, P302+P352, P304+P340, P305+P354+P338, P316, P317, P319, P320, P321, P332+P317, P362+P364, P377, P381, P403, P403+P233, P405, P501
NFPA 704 (fire diamond)	4 4 1
Flash point	−107 °C (−161 °F; 166 K)
Explosive limits	5.5–18%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	1300 mg/kg (oral, rat)
LC50 (median concentration)	17 ppm (mouse, 10 min)
LCLo (lowest published)	23 ppm (mouse, 30 min); 53 ppm (rabbit, 2 hr); 53 ppm (guinea pig, 2 hr); 750 ppm (cat, 10 min); 200 ppm (monkey, 10 min); 50 ppm (mouse, 10 min); 1000 ppm (rabbit, 10 min)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 0.5 ppm (0.9 mg/m3)
REL (Recommended)	TWA 0.5 ppm (0.9 mg/m3) ST 1.5 ppm (3 mg/m3)
IDLH (Immediate danger)	5 ppm
Safety data sheet (SDS)	External MSDS
	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

Ethenone is the formal name for ketene, an organic compound with formula C₂H₂O or H₂C=C=O. It is the simplest member of the ketene class. It is an important reagent for acetylations.