Editing Propionic acid (section)

{{short description|Carboxylic acid with chemical formula CH<sub>3</sub>CH<sub>2</sub>CO<sub>2</sub>H}}
{{Use dmy dates|date=February 2021}}
{{Chembox
| Name           = Propionic acid
| ImageFileL1    = Propionic_acid_chemical_structure.svg
| ImageSizeL1    = 100px
| ImageClassL1   = skin-invert
| ImageNameL1    = Simplified skeletal formula
| ImageFileR1    = Propionic_acid_flat_structure.png
| ImageSizeR1    = 100px
| ImageClassR1   = skin-invert
| ImageNameR1    = Full structural formula
| ImageFileL2    = Propionic-acid-3D-balls.png
| ImageSizeL2    = 100px
| ImageNameL2    = Ball-and-stick model
| ImageFileR2    = Propionic acid spheres.png
| ImageSizeR2    = 100px
| ImageNameR2    = Space-filling model
| ImageFile3     = Propionic acid.jpg
| ImageSize3     = 200px
| PIN            = Propanoic acid <!-- Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) -->
| OtherNames     = Carboxyethane<br />Ethanecarboxylic acid<br />Ethylformic acid<br />Metacetonic acid<br />Methylacetic acid<br />C3:0 ([[Fatty acid#Nomenclature|Lipid numbers]])
| Section1       = {{Chembox Identifiers
| index_label    = Propionic acid
| index1_label   = Propionate
| IUPHAR_ligand = 1062
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB03766
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 30768
| SMILES = CCC(=O)O
| EINECS =   201-176-3
| CASNo = 79-09-4
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = JHU490RVYR
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 14021
| PubChem = 1032
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 1005
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C3H6O2/c1-2-3(4)5/h2H2,1H3,(H,4,5)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = XBDQKXXYIPTUBI-UHFFFAOYSA-N
| RTECS = UE5950000
| CASNo1 = 72-03-7
| CASNo1_Ref = {{cascite|correct|CAS}}
| UNII1 = AKW5EM890C
| UNII1_Ref = {{fdacite|correct|FDA}}
| SMILES1 = CCC(=O)[O-]
| PubChem1 = 104745
| ChemSpiderID1 = 94556
 }}
| Section2       = {{Chembox Properties
| C=3 | H=6 | O=2
| Appearance = Colorless, oily liquid<ref name=PGCH/>
| Odor = Pungent, rancid, unpleasant<ref name=PGCH/>
| Density = 0.98797 g/cm<sup>3</sup><ref name=cons3 />
| Solubility = 8.19 g/g (−28.3&nbsp;°C)<br /> 34.97 g/g (−23.9&nbsp;°C)<br /> Miscible (≥ −19.3&nbsp;°C)<ref name=sioc>{{cite book|last1 = Seidell|first1 = Atherton|last2 = Linke|first2 = William F.|year = 1919|title = Solubilities of Inorganic and Organic Compounds|url = https://archive.org/details/solubilitiesino01seidgoog|publisher = D. Van Nostrand Company|edition = 2nd|page = 569}}</ref>
| SolubleOther = Miscible in [[Ethanol|EtOH]], [[Diethyl ether|ether]], [[Chloroform|{{chem|CHCl|3}}]]<ref name=chemister>{{Cite web |url=http://chemister.ru/Database/properties-en.php?dbid=1&id=1485 |title=chemister.ru (archived copy) |access-date=13 June 2014 |archive-url=https://web.archive.org/web/20161009114215/http://chemister.ru/Database/properties-en.php?dbid=1&id=1485 |archive-date=9 October 2016 |url-status=dead }}</ref>
| MeltingPtC = −20.5
| MeltingPt_ref =<ref name=crc>{{CRC90}}</ref>
| BoilingPtC = 141.15
| BoilingPt_ref =<ref name=crc />
| pKa = 4.88<ref name=pubchem />
| Viscosity = 1.175 c[[Poise (unit)|P]] (15&nbsp;°C)<ref name=cons3 /><br /> 1.02 cP (25&nbsp;°C)<br /> 0.668 cP (60&nbsp;°C)<br /> 0.495 cP (90&nbsp;°C)<ref name=pubchem>{{PubChemLink|1032}}</ref>
| RefractIndex = 1.3843<ref name=cons3>{{cite book|editor-last = Lagowski|editor-first = J.J.|year = 2012|title = The Chemistry of Nonaqueous Solvents|publisher = Elsevier|page = 362|volume = III|url = https://books.google.com/books?id=bXUSMbnCjhUC&pg=PA362|isbn = 978-0323151030}}</ref>
| SublimationConditions = Sublimes at −48&nbsp;°C<br /> Δ<sub>subl</sub>''H''<sup><s>o</s></sup> = 74 kJ/mol<ref name=nist />
| VaporPressure = 0.32 kPa (20&nbsp;°C)<ref name="sigma" /><br /> 0.47 kPa (25&nbsp;°C)<ref name=pubchem /><br /> 9.62 kPa (100&nbsp;°C)<ref name=nist />
| HenryConstant = 4.45·10<sup>−4</sup> L·atm/mol<ref name=pubchem />
| LogP = 0.33<ref name=pubchem />
| MagSus = −43.50·10<sup>−6</sup> cm<sup>3</sup>/mol
 }}
| Section3       = {{Chembox Structure
| Dipole = 0.63 [[Debye|D]] (22&nbsp;°C)<ref name=cons3 />
| CrystalStruct = [[monoclinic crystal system|Monoclinic]] (−95&nbsp;°C)<ref name=csba>{{Cite journal | doi = 10.1107/S0365110X62003278| title = The crystal structure of propionic acid| journal = Acta Crystallographica| volume = 15| issue = 12| pages = 1233–1239| year = 1962| last1 = Strieter | first1 = F. J.| last2 = Templeton | first2 = D. H.| last3 = Scheuerman | first3 = R. F.| last4 = Sass | first4 = R. L.| bibcode = 1962AcCry..15.1233S| url = http://www.escholarship.org/uc/item/55b9n7jj}}</ref>
| SpaceGroup = P2<sub>1</sub>/c<ref name=csba />
| LattConst_a = 4.04&nbsp;Å
| LattConst_b = 9.06&nbsp;Å
| LattConst_c = 11&nbsp;Å<ref name=csba />
| LattConst_alpha =
| LattConst_beta = 91.25
| LattConst_gamma =
 }}
| Section4       = {{Chembox Thermochemistry
| DeltaHf = −510.8 kJ/mol<ref name=nist>{{nist|name=Propanoic acid| id= C79094|accessdate=13 June 2014|mask=FFFF|units=SI}}</ref>
| DeltaHc = 1527.3 kJ/mol<ref name=cons3 /><ref name=nist />
| HeatCapacity = 152.8 J/mol·K<ref name=chemister /><ref name=nist />
| Entropy = 191 J/mol·K<ref name=nist />
 }}
| Section7       = {{Chembox Hazards
| GHSPictograms = {{GHS02}}{{GHS05}}{{GHS07}}
| GHS_ref=<ref name="sigma">{{Sigma-Aldrich| id= w292400|name=Propionic acid|accessdate=13 June 2014}}</ref>
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|314}}<ref name="sigma" />
| PPhrases = {{P-phrases|280|305+351+338|310}}<ref name="sigma" />
| MainHazards = Corrosive
| NFPA-H = 3
| NFPA-F = 2
| NFPA-R = 0
| FlashPtC = 54
| FlashPt_ref =<ref name="sigma" />
| AutoignitionPtC = 512
| LD50 = 1370 mg/kg (mouse, oral)<ref name=chemister />
| PEL = none<ref name=PGCH>{{PGCH|0529}}</ref>
| IDLH = N.D.<ref name=PGCH/>
| REL = TWA 10 ppm (30 mg/m<sup>3</sup>) ST 15 ppm (45 mg/m<sup>3</sup>)<ref name=PGCH/>
 }}
| Section8       = {{Chembox Related
| OtherAnions =
| OtherFunction_label = [[Carboxylic acid]]s
| OtherFunction = [[Acetic acid]]<br /> [[Lactic acid]]<br /> [[3-Hydroxypropionic acid]]<br /> [[Tartronic acid]]<br /> [[Acrylic acid]]<br /> [[Butyric acid]]
| OtherCompounds = [[1-Propanol]]<br /> [[Propionaldehyde]]<br /> [[Sodium propionate]]<br /> [[Propionic anhydride]]}}
}}

'''Propionic acid''' ({{IPAc-en|p|r|oʊ|p|i|ˈ|ɒ|n|ɪ|k}}, from the [[Greek language|Greek]] words πρῶτος : ''prōtos'', meaning "first", and πίων : ''píōn'', meaning "fat"; also known as '''propanoic acid''') is a naturally occurring [[carboxylic acid]] with [[chemical formula]] {{chem|CH|3|CH|2|CO|2|H}}. It is a liquid with a pungent and unpleasant smell somewhat resembling [[body odor]]. The [[anion]] {{chem|CH|3|CH|2|CO|2|-}} as well as the [[Carboxylate salt|salts]] and [[ester]]s of propionic acid are known as '''propionates''' or '''propanoates'''.

About half of the world production of propionic acid is consumed as a [[preservative]] for both animal feed and food for human consumption. It is also useful as an intermediate in the production of other chemicals, especially polymers.