Butanone

Butanone
	Skeletal formula of butanone
Ball-and-stick model of butanone	Space-filling model of butanone
	methyl ethyl ketone
Names
	Preferred IUPAC name Butan-2-one
	Other names 2-Butanone; Ethyl methyl ketone; Ethylmethylketone; Methyl ethyl ketone (MEK; deprecated); Methylpropanone; Methylacetone;
Identifiers
CAS Number	78-93-3 ;
3D model (JSmol)	Interactive image; Interactive image;
Beilstein Reference	741880
ChEBI	CHEBI:28398 ;
ChEMBL	ChEMBL15849 ;
ChemSpider	6321 ;
ECHA InfoCard	100.001.054
EC Number	201-159-0;
Gmelin Reference	25656
KEGG	C02845 ;
PubChem CID	6569;
RTECS number	EL6475000;
UNII	6PT9KLV9IO ;
UN number	1193
CompTox Dashboard (EPA)	DTXSID3021516 ;
	InChI InChI=1S/C4H8O/c1-3-4(2)5/h3H2,1-2H3 Key: ZWEHNKRNPOVVGH-UHFFFAOYSA-N ; InChI=1/C4H8O/c1-3-4(2)5/h3H2,1-2H3 Key: ZWEHNKRNPOVVGH-UHFFFAOYAW;
	SMILES O=C(C)CC; CCC(=O)C;
Properties
Chemical formula	C4H8O
Molar mass	72.107 g·mol−1
Appearance	Colorless liquid
Odor	Mint or acetone-like
Density	0.8050 g/mL
Melting point	−86 °C (−123 °F; 187 K)
Boiling point	79.64 °C (175.35 °F; 352.79 K)
Solubility in water	27.5 g/100 mL
log P	0.37
Vapor pressure	78 mmHg (20 °C)
Acidity (pKa)	14.7
Magnetic susceptibility (χ)	−45.58·10−6 cm3/mol
Refractive index (nD)	1.37880
Viscosity	0.43 cP
Structure
Dipole moment	2.76 D
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H319, H336
Precautionary statements	P210, P233, P240, P241, P242, P243, P261, P264, P271, P280, P303+P361+P353, P304+P340, P305+P351+P338, P312, P337+P313, P370+P378, P403+P233, P403+P235, P405, P501
NFPA 704 (fire diamond)	1 3 0
Flash point	−9 °C (16 °F; 264 K)
Autoignition; temperature	505 °C (941 °F; 778 K)
Explosive limits	1.4–11.4%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	2737 mg/kg (oral, rat); 4050 mg/kg (oral, mouse);
LC50 (median concentration)	12667 ppm (mammal); 13333 ppm (mouse, 2 hr); 7833 ppm (rat, 8 hr);
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 200 ppm (590 mg/m3)
REL (Recommended)	TWA 200 ppm (590 mg/m3) ST 300 ppm (885 mg/m3)
IDLH (Immediate danger)	3000 ppm
Safety data sheet (SDS)	Safety Data Sheet
Related compounds
Related ketones	Acetone; 3-Pentanone; 3-Methylbutanone;
Supplementary data page
	Butanone (data page)
	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

Butanone, also known as methyl ethyl ketone (MEK) or ethyl methyl ketone, is an organic compound with the formula CH₃C(O)CH₂CH₃. This colorless liquid ketone has a sharp, sweet odor reminiscent of acetone. It is produced industrially on a large scale, but occurs in nature only in trace amounts. It is partially soluble in water, and is commonly used as an industrial solvent. It is an isomer of another solvent, tetrahydrofuran.