Acetic acid

Acetic acid, or ethanoic acid, (CH₃COOH) is a carboxylic acid. It is the main compound of vinegar, other than water.

Acetic acid
File:Acetic-acid-2D-skeletal.svg	File:Acetic-acid-CRC-GED-3D-vdW-B.png
File:Essigsäure - Acetic acid.svg
Preferred IUPAC name Acetic acid
Systematic name Ethanoic acid
Other names	Vinegar (when dilute); Hydrogen acetate; Methanecarboxylic acid
Identifiers
Abbreviations	AcOH
CAS number	64-19-7
PubChem	176
EC number	200-580-7
DrugBank	DB03166
KEGG	D00010
MeSH	Acetic+acid
ChEBI	CHEBI:15366
RTECS number	AF1225000
SMILES	CC(O)=O
Beilstein Reference	506007
Gmelin Reference	1380
3DMet	B00009
Properties
Molecular formula	C2H4O2
Molar mass	60.04 g mol-1
Appearance	Colourless liquid
Odor	Pungent/Vinegar-like
Density	1.049 g cm−3 (liquid); 1.27 g cm cm−3 (solid)
Melting point	°C, 289 to 290 K,  °F
Boiling point
Solubility in water	Miscible
log P	-0.28
Acidity (pKa)	4.756 (H2O) 12.6 (DMSO)
Basicity (pKb)	9.24 (basicity of acetate ion)
Magnetic susceptibility (χ)	-31.54·10−6 cm3/mol
Refractive index (nD)	1.371
Viscosity	1.22 mPa s
Dipole moment	1.74 D
Thermochemistry
Std enthalpy of formation ΔfHo298	-483.88—483.16 kJ mol−1
Std enthalpy of combustion ΔcHo298	-875.50—874.82 kJ mol−1
Standard molar entropy So298	158.0 J K−1 mol−1
Specific heat capacity, C	123.1 J K−1 mol−1
Pharmacology
ATC code
Hazards
NFPA 704	2 3 0
Explosive limits	4–16%
U.S. Permissible exposure limit (PEL)	TWA 10 ppm (25 mg/m3)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Vinegar contains acetic acid. Aceto balsamico, vinegar from red and from white wine.

It tastes and smells sour; it has no color. Its melting point is 16.5 °C (61.6 °F) and its boiling point is 118.1 °C (244.5 °F). It has a pH of 2.4.

Acetic acid is commonly used as a food additive. It has the E numbers E 260 (acetic acid).

Potassium acetate (E 261), sodium acetate (E 262), and calcium acetate (E 2639) are salts of acetic acid; they are commonly used to preserve food, usually vegetables. In sourdough, ethanol fermentation is used.

Acetic Acid Media

• AceticAcid

• AceticAcid

• Deprotonation equilibrium of acetic acid in water

• Acetic Acid Hydrogenbridge V.1.svg

  Cyclic dimer of acetic acid; dashed green lines represent hydrogen bonds

• Acetic acid 1884 plant.jpg

  Purification and concentration plant for acetic acid in 1884

• Methanol formylation.png

  Reaction of methanol and carbon monoxide in the presence of various catalysts gives acetic acid

References

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