Butyric acid

Butyric acid

Names
Preferred IUPAC name Butanoic acid
Other names Butyric acid 1-Propanecarboxylic acid Propanecarboxylic acid C4:0 (Lipid numbers)
Identifiers
CAS Number	107-92-6 Y
3D model (Jmol)	Interactive image Interactive image
ChEBI	CHEBI:30772 Y
ChEMBL	ChEMBL14227 Y
ChemSpider	259 Y
DrugBank	DB03568 Y
ECHA InfoCard	100.003.212
EC Number	203-532-3
IUPHAR/BPS	1059
KEGG	C00246 Y
MeSH	Butyric+acid
PubChem	264
RTECS number	ES5425000
UNII	40UIR9Q29H Y
UN number	2820
InChI InChI=1S/C4H8O2/c1-2-3-4(5)6/h2-3H2,1H3,(H,5,6) Y Key: FERIUCNNQQJTOY-UHFFFAOYSA-N Y InChI=1/C4H8O2/c1-2-3-4(5)6/h2-3H2,1H3,(H,5,6) Key: FERIUCNNQQJTOY-UHFFFAOYAP
SMILES O=C(O)CCC CCCC(=O)O
Properties
Chemical formula	C 3H 7COOH
Molar mass	88.11 g·mol−1
Appearance	Colorless liquid
Odor	Unpleasant and obnoxious
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	Slightly soluble in CCl4 Miscible with ethanol, ether
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
Specific heat capacity (C)	178.6 J/mol·K
Std molar entropy (So298)	222.2 J/mol·K
Std enthalpy of formation (ΔfHo298)	−533.9 kJ/mol
Std enthalpy of combustion (ΔcHo298)	2183.5 kJ/mol
Hazards
Safety data sheet	External MSDS
GHS pictograms
GHS signal word	Danger
GHS hazard statements	H314
GHS precautionary statements	P280, P305+351+338, P310
EU classification (DSD)	Xn C
R-phrases	R20/21/22, R34, R36/37/38
S-phrases	S26, S36, S45
NFPA 704	2 3 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)
Related compounds
Other anions	Butyrate
Related Carboxylic acids	Propionic acid Acrylic acid Succinic acid Malic acid Tartaric acid Crotonic acid Fumaric 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).
Y  (what is YN ?)
Infobox references

Butyric acid (from Greek βούτῡρον, meaning "butter"), also known under the systematic name butanoic acid, abbreviated BTA, is a carboxylic acid with the structural formula CH₃CH₂CH₂-COOH. Salts and esters of butyric acid are known as butyrates or butanoates. Butyric acid is found in milk, especially goat, sheep and buffalo milk, butter, parmesan cheese, and as a product of anaerobic fermentation (including in the colon and as body odor). It is also found in milk chocolate produced by the Hershey process, or added to imitate the flavour of Hershey's chocolate. Butyric acid is present in, and is the main distinctive smell of, human vomit. It has an unpleasant smell and acrid taste, with a sweetish aftertaste similar to ether. Mammals with good scent detection abilities, such as dogs, can detect it at 10 parts per billion, whereas humans can detect it in concentrations above 10 parts per million.

Butyric acid was first observed in impure form in 1814 by the French chemist Michel Eugène Chevreul. By 1818, he had purified it sufficiently to characterize it. However, Chevreul did not publish his early research on butyric acid; instead, he deposited his findings in manuscript form with the secretary of the Academy of Sciences in Paris, France. Henri Braconnot, a French chemist, was also researching the composition of butter and was publishing his findings, and this led to disputes about priority. As early as 1815, Chevreul claimed that he had found the substance responsible for the smell of butter. By 1817, he published some of his findings regarding the properties of butyric acid and named it. However, it was not until 1823 that he presented the properties of butyric acid in detail. The name of butyric acid comes from the Latin word for butter, butyrum (or buturum), the substance in which butyric acid was first found.