Butyric acid

Butyric acid
Names
	Preferred IUPAC name Butanoic acid
	Other names Ethylacetic acid; 1-Propanecarboxylic acid; Propylformic acid; C4:0 (Lipid numbers)
Identifiers
CAS Number	Butyric acid: 107-92-6 ; Butyrate: 461-55-2 ;
3D model (JSmol)	Butyric acid: Interactive image;
ChEBI	Butyric acid: CHEBI:30772 ;
ChEMBL	Butyric acid: ChEMBL14227 ;
ChemSpider	Butyric acid: 259 ; Butyrate: 94582 ;
DrugBank	Butyric acid: DB03568 ;
ECHA InfoCard	100.003.212
EC Number	Butyric acid: 203-532-3;
IUPHAR/BPS	Butyric acid: 1059;
KEGG	Butyric acid: C00246 ;
MeSH	Butyric+acid
PubChem CID	Butyric acid: 264; Butyrate: 104775;
RTECS number	Butyric acid: ES5425000;
UNII	Butyric acid: 40UIR9Q29H ;
UN number	2820
CompTox Dashboard (EPA)	Butyric acid: DTXSID8021515 ;
	InChI InChI=1S/C4H8O2/c1-2-3-4(5)6/h2-3H2,1H3,(H,5,6) Key: FERIUCNNQQJTOY-UHFFFAOYSA-N ; Butyric acid: InChI=1/C4H8O2/c1-2-3-4(5)6/h2-3H2,1H3,(H,5,6) Key: FERIUCNNQQJTOY-UHFFFAOYAP;
	SMILES Butyric acid: O=C(O)CCC;
Properties
Chemical formula	C; 3H; 7COOH
Molar mass	88.106 g·mol−1
Appearance	Colorless liquid
Odor	Unpleasant, similar to vomit or body odor
Density	1.135 g/cm3 (−43 °C); 0.9528 g/cm3 (25 °C)
Melting point	−5.1 °C (22.8 °F; 268.0 K)
Boiling point	163.75 °C (326.75 °F; 436.90 K)
Sublimation; conditions	Sublimes at −35 °C; ΔsublHo = 76 kJ/mol
Solubility in water	Miscible
Solubility	Miscible with ethanol, ether. Slightly soluble in CCl4
log P	0.79
Vapor pressure	0.112 kPa (20 °C); 0.74 kPa (50 °C); 9.62 kPa (100 °C)
Henry's law; constant (kH)	5.35·10−4 L·atm/mol
Acidity (pKa)	4.82
Magnetic susceptibility (χ)	−55.10·10−6 cm3/mol
Thermal conductivity	1.46·105 W/m·K
Refractive index (nD)	1.398 (20 °C)
Viscosity	1.814 cP (15 °C); 1.426 cP (25 °C)
Structure
Crystal structure	Monoclinic (−43 °C)
Space group	C2/m
Lattice constant	a = 8.01 Å, b = 6.82 Å, c = 10.14 Å α = 90°, β = 111.45°, γ = 90°
Dipole moment	0.93 D (20 °C)
Thermochemistry
Heat capacity (C)	178.6 J/mol·K
Std molar; entropy (S⦵298)	222.2 J/mol·K
Std enthalpy of; formation (ΔfH⦵298)	−533.9 kJ/mol
Std enthalpy of; combustion (ΔcH⦵298)	2183.5 kJ/mol
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H314
Precautionary statements	P280, P305+P351+P338, P310
NFPA 704 (fire diamond)	3 2 0
Flash point	71 to 72 °C (160 to 162 °F; 344 to 345 K)
Autoignition; temperature	440 °C (824 °F; 713 K)
Explosive limits	2.2–13.4%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	2000 mg/kg (oral, rat)
Safety data sheet (SDS)	External MSDS
Related compounds
Related carboxylic acids	Propionic acid, Pentanoic acid
Related compounds	1-Butanol; Butyraldehyde; Methyl butyrate
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Butyric acid (/ˈbjuːtɪrɪk/; from Ancient Greek: βούτῡρον, meaning "butter"), also known under the systematic name butanoic acid, is a straight-chain alkyl carboxylic acid with the chemical formula CH₃CH₂CH₂COOH. It is an oily, colorless liquid with an unpleasant odor. Isobutyric acid (2-methylpropanoic acid) is an isomer. Salts and esters of butyric acid are known as butyrates or butanoates. The acid does not occur widely in nature, but its esters are widespread. It is a common industrial chemical^[7] and an important component in the mammalian gut.

^ "Applications to Specific Classes of Compounds". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 746. doi:10.1039/9781849733069-00648. ISBN 978-0-85404-182-4.
^ ^a ^b ^c ^d Strieter FJ, Templeton DH (1962). "Crystal structure of butyric acid" (PDF). Acta Crystallographica. 15 (12): 1240–1244. Bibcode:1962AcCry..15.1240S. doi:10.1107/S0365110X6200328X.
^ ^a ^b ^c ^d Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0.
^ ^a ^b ^c ^d ^e Butanoic acid in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (retrieved 27 October 2020)
^ ^a ^b ^c "Butanoic acid". Chemister.ru. 19 March 2007. Retrieved 27 October 2020.
^ ^a ^b ^c ^d ^e Sigma-Aldrich Co., Butyric acid. Retrieved on 27 October 2020.
^ Riemenschneider, Wilhelm (2002). "Carboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a05_235. ISBN 978-3-527-30673-2.

[iupac2013-1] "Applications to Specific Classes of Compounds". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 746. doi:10.1039/9781849733069-00648. ISBN 978-0-85404-182-4.

[csba-2] Strieter FJ, Templeton DH (1962). "Crystal structure of butyric acid" (PDF). Acta Crystallographica. 15 (12): 1240–1244. Bibcode:1962AcCry..15.1240S. doi:10.1107/S0365110X6200328X.

[crc-3] Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0.

[nist-4] Butanoic acid in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (retrieved 27 October 2020)

[chemister-5] "Butanoic acid". Chemister.ru. 19 March 2007. Retrieved 27 October 2020.

[sigma-6] Sigma-Aldrich Co., Butyric acid. Retrieved on 27 October 2020.

[Ullmann-7] Riemenschneider, Wilhelm (2002). "Carboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a05_235. ISBN 978-3-527-30673-2.

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