Butanone

Butanone, also called methyl ethyl ketone (MEK), is an organic compound with the chemical formula CH3C(O)CH2CH3. It is a simple ketone with four carbon atoms. It smells sharp and sweet, like butterscotch and acetone mixed. It is soluble in water and is used as a solvent.

Butanone[1]
Butanone-skeletal-structure.svg
Butanone-3D-balls.png
Butanone-3D-vdW.png
Methyl ethyl ketone 45ml.jpg
Other names
  • Ethyl methyl ketone[2]
  • Ethylmethylketone
  • Methyl ethyl ketone (MEK; deprecated[2])
  • Methylpropanone
  • Methylacetone
Identifiers
CAS number 78-93-3
PubChem 6569
KEGG C02845
ChEBI CHEBI:28398
RTECS number EL6475000
SMILES O=C(C)CC
Beilstein Reference 741880
Gmelin Reference 25656
Properties
Molecular formula C4H8O
Molar mass 72.1 g mol-1
Appearance Colorless liquid
Odor Mint or acetone-like[3]
Density 0.8050 g/mL
Melting point

−86 °C, 187 K, -123 °F

Boiling point
Solubility in water 27.5 g/100mL
log P 0.37[4]
Vapor pressure 78 mmHg (20 °C)[3]
Acidity (pKa) 14.7
−45.58·10−6 cm3/mol
Refractive index (nD) 1.37880
Viscosity 0.43 cP
Structure
Dipole moment 2.76 D
Hazards
EU classification Flammable (F)
Irritant (Xi)
NFPA 704

NFPA 704.svg

3
1
0
 
R-phrases R11 R36 R66 R67
S-phrases (S2) S9 S16
Explosive limits 1.4–11.4%[3]
U.S. Permissible
exposure limit (PEL)
TWA 200 ppm (590 mg/m3)[3]
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Butanone Media

References

  1. Merck Index, 11th Edition, 5991.
  2. 2.0 2.1 2.2 Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 725. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  3. 3.0 3.1 3.2 3.3 NIOSH Pocket Guide to Chemical Hazards. "#0069". National Institute for Occupational Safety and Health (NIOSH).
  4. "butan-2-one_msds".