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Acetic acid, or ethanoic acid, (CH3COOH) is a carboxylic acid, which is the main compound of vinegar, other than water. It tastes and smells sour; it has no color. Its melting point is 16.5 °C(61.6 °F) and boiling point is 118.1 °C(244.5 °F). It has a pH of 2.4.

Acetic acid
Skeletal formula of acetic acid
Spacefill model of acetic acid
Skeletal formula of acetic acid with all explicit hydrogens added
Ball and stick model of acetic acid
Names
Preferred IUPAC name
Acetic acid[3]
Systematic IUPAC name
Ethanoic acid
Other names
Vinegar (when dilute); Hydrogen acetate; Methanecarboxylic acid[1][2]
Identifiers
3D model (JSmol)
3DMet {{{value}}}
Abbreviations AcOH
Beilstein Reference 506007
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.528
EC Number 200-580-7
E number E260 (preservatives)
Gmelin Reference 1380
KEGG
MeSH {{{value}}}
PubChem {{{value}}}
RTECS number AF1225000
UNII
UN number 2789
SMILES {{{value}}}
Properties
C2H4O2
Molar mass 60.05 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 16 to 17 °C; 61 to 62 °F; 289 to 290 K
Boiling point 118 to 119 °C; 244 to 246 °F; 391 to 392 K
Miscible
log P -0.28[4]
Acidity (pKa)
Basicity (pKb) 9.24 (basicity of acetate ion)
Conjugate base Acetate
-31.54·10−6 cm3/mol
1.371
Viscosity 1.22 mPa s
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
G01AD02 (WHO) S02AA10 (WHO)
Hazards
NFPA 704

NFPA 704.svg

2
3
0
 
Explosive limits 4–16%
U.S. Permissible
exposure limit (PEL)
TWA 10 ppm (25 mg/m3)[7]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

ReferencesEdit

  1. Scientific literature reviews on generally recognised as safe (GRAS) food ingredients. National Technical Information Service. 1974. p. 1.
  2. "Chemistry", volume 5, Encyclopædia Britannica, 1961, page 374
  3. Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 745. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  4. "acetic acid_msds".
  5. Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. pp. 5–88. ISBN 9781498754293.
  6. Bordwell, F. G.; Algrim, Donald (1976). "Nitrogen acids. 1. Carboxamides and sulfonamides". The Journal of Organic Chemistry 41 (14): 2507–2508. doi:10.1021/jo00876a042. 
  7. "NIOSH Pocket Guide to Chemical Hazards #0002". National Institute for Occupational Safety and Health (NIOSH).