{{Chembox
| Verifiedfields = chynged
| Watchedfields = chynged
| verifiedrevid = 477238786
| ImageFile3 = Acetic acid.jpg
| ImageFile3_Ref = {{chemboximage|correct|??}}
| ImageSize3 = 244
| ImageName3 = Sample o acetic acid in a reagent bottle
| ImageFileL1 = Acetic-acid-2D-skeletal.svg
| ImageFileL1_Ref = {{chemboximage|correct|??}}
| ImageNameL1 = Skeletal formula o acetic acid
| ImageFileR1 = Acetic-acid-CRC-GED-3D-vdW-B.png
| ImageFileR1_Ref = {{chemboximage|correct|??}}
| ImageNameR1 = Spacefill model o acetic acid
| ImageFileL2 =Acetic-acid-2D-flat.png
| ImageFileL2_Ref = {{chemboximage|correct|??}}
| ImageNameL2 = Skeletal formula o acetic acid wi aw explicit hydogens addit
| ImageFileR2 = Acetic-acid-CRC-GED-3D-balls-B.png
| ImageFileR2_Ref = {{chemboximage|correct|??}}
| ImageNameR2 = Baw an stick model o acetic acid
| IUPACName = Acetic acid<ref>{{cite book | title=A Guide to IUPAC Nomenclature of Organic Compounds (Recommendations 1993) | publisher=Blackwell Scientific publications | author=IUPAC, Commission on Nomenclature of Organic Chemistry | year=1993 | chapter=Table 28(a) Carboxylic acids and related groups. Unsubstituted parent structures | url=http://www.acdlabs.eu/iupac/nomenclature/93/r93_705.htm | isbn=0-632-03488-2 | access-date=2014-04-28 | archive-date=2018-12-25 | archive-url=https://web.archive.org/web/20181225011608/http://www.acdlabs.eu/iupac/nomenclature/93/r93_705.htm%20 | url-status=dead }}</ref><ref>{{cite web|url = http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=176|title = Acetic Acid - PubChem Public Chemical Database|work = The PubChem Project|location = USA|publisher = National Center for Biotechnology Information}}</ref>
| SystematicName = Ethanoic acid<ref name="BB-prs310305">IUPAC Provisional Recommendations 2004 [http://old.iupac.org/reports/provisional/abstract04/BB-prs310305/Chapter1.pdf Chapter P-12.1; page 4]</ref>
| OtherNames = Methanecarboxylic acid<ref>{{cite book|title=Scientific literature reviews on generally recognized as safe (GRAS) food ingredients|publisher=National Technical Information Service|year=1974|page=1}}</ref><ref>"Chemistry", volume 5, Encyclopedia Britannica, 1961, page 374</ref>
| Section1 = {{Chembox Identifiers
|  Abbreviations = AcOH
|  CASNo = 64-19-7
|  CASNo_Ref = {{cascite|correct|CAS}}
|  PubChem = 176
|  PubChem_Ref = {{Pubchemcite|correct|pubchem}}
|  ChemSpiderID = 171
|  ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
|  UNII = Q40Q9N063P
|  UNII_Ref = {{fdacite|correct|FDA}}
|  EINECS = 200-580-7
|  UNNumber = 2789
|  DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB03166
|  KEGG = D00010
|  KEGG_Ref = {{keggcite|changed|kegg}}
|  MeSHName = Acetic+acid
|  ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 15366
|  ChEMBL = 539
|  ChEMBL_Ref = {{ebicite|correct|EBI}}
|  IUPHAR_ligand = 1058
|  RTECS = AF1225000
|  ATCCode_prefix = G01
|  ATCCode_suffix = AD02
|  ATC_Supplemental = {{ATC|S02|AA10}}
|  Beilstein = 506007
|  Gmelin = 1380
|  3DMet = B00009
|  RTECS = AF1225000
|  SMILES = CC(O)=O
|  StdInChI = 1S/C2H4O2/c1-2(3)4/h1H3,(H,3,4)
|  StdInChI_Ref = {{stdinchicite|correct|chemspider}}
|  StdInChIKey = QTBSBXVTEAMEQO-UHFFFAOYSA-N
|  StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
| Section2 = {{Chembox Properties
|  C = 2
|  H = 4
|  O = 2
|  ExactMass = 60.021129372 g mol<sup>-1</sup>
|  Appearance = Colourless liquid
|  Odor = vinegar-like
|  Density = 1.049 g cm<sup>-3</sup>
|  Solubility = [[Miscible]]
|  MeltingPtK = 289
|  MeltingPtKH = 290
|  BoilingPtK = 391
|  BoilingPtKH = 392
|  LogP = -0.322
|  pKa = 4.76
|  pKb = 9.198
|  Viscosity = 1.22 mPa s
|  RefractIndex = 1.371
|  Dipole = 1.74 D
}}
| Section4 = {{Chembox Thermochemistry
|  DeltaHf = -483.88--483.16 kJ mol<sup>-1</sup>
|  DeltaHc = -875.50--874.82 kJ mol<sup>-1</sup>
|  Entropy = 158.0 J K<sup>-1</sup> mol<sup>-1</sup>
|  HeatCapacity = 123.1 J K<sup>-1</sup> mol<sup>-1</sup>
}}
| Section5 = {{Chembox Hazards
|  GHSPictograms = {{GHS02}} {{GHS05}}
|  GHSSignalWord = Danger
|  HPhrases = {{H-phrases|226|314}}
|  PPhrases = {{P-phrases|280|305+351+338|310}}
|  EUIndex = 607-002-00-6
|  EUClass = {{Hazchem C}}
|  RPhrases = {{R10}}, {{R35}}
|  SPhrases = {{S1/2}}, {{S23}}, {{S26}}, {{S45}}
|  NFPA-F = 2
|  NFPA-H = 3
|  NFPA-R = 0
|  FlashPtC = 40
|  AutoignitionC = 427
|  LD50 = 3.31 g kg<sup>-1</sup>, oral (rat)
|  ExploLimits = 4-16%
}}
| Section6 = {{Chembox Related
|  Function = [[carboxylic acid]]s
|  OtherFunctn = [[Formic acid]]<br />[[Propionic acid]]
|  OtherCpds = [[Acetaldehyde]]<br />
[[Acetamide]]<br />
[[Acetic anhydride]]<br />
[[Acetonitrile]]<br />
[[Acetyl chloride]]<br />
[[Ethanol]]<br />
[[Ethyl acetate]]<br />
[[Potassium acetate]]<br />
[[Sodium acetate]]<br />
[[Thioacetic acid]]
}}
}}
'''Acetic acid''' {{IPAc-en|ə|ˈ|s|iː|t|ɨ|k}} (seestematically named '''ethanoic acid''' {{IPAc-en|ˌ|ɛ|θ|ə|ˈ|n|oʊ|ɨ|k}}) is an [[organic compoond]] wi the [[chemical formula]] CH<sub>3</sub>COOH (an aa written as CH<sub>3</sub>CO<sub>2</sub>H or C<sub>2</sub>H<sub>4</sub>O<sub>2</sub>).