Palmitic acid

Palmitic acid

Names
Preferred IUPAC name Hexadecanoic acid
Other names Palmitic acid C16:0 (Lipid numbers)
Identifiers
CAS Number	57-10-3 Y
3D model (Jmol)	Interactive image
ChEMBL	ChEMBL82293 N
ChemSpider	960 N
ECHA InfoCard	100.000.284
IUPHAR/BPS	1055
PubChem	985
InChI InChI=1S/C16H32O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16(17)18/h2-15H2,1H3,(H,17,18) N Key: IPCSVZSSVZVIGE-UHFFFAOYSA-N N InChI=1/C16H32O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16(17)18/h2-15H2,1H3,(H,17,18) Key: IPCSVZSSVZVIGE-UHFFFAOYAJ
SMILES CCCCCCCCCCCCCCCC(=O)O
Properties
Chemical formula	C16H32O2
Molar mass	256.43 g·mol−1
Appearance	white crystals
Density	0.852 g/cm3 (25 °C) 0.8527 g/cm3 (62 °C)
Melting point	62.9 °C (145.2 °F; 336.0 K)
Boiling point	351–352 °C (664–666 °F; 624–625 K) 271.5 °C (520.7 °F; 544.6 K) at 100 mmHg 215 °C (419 °F; 488 K) at 15 mmHg
Solubility in water	0.46 mg/L (0 °C) 0.719 mg/L (20 °C) 0.826 mg/L (30 °C) 0.99 mg/L (45 °C) 1.18 mg/L (60 °C)
Solubility	soluble in amyl acetate, alcohol, CCl4,C6H6 very soluble in CHCl3
Solubility in ethanol	2 g/100 mL (0 °C) 2.8 g/100 mL (10 °C) 9.2 g/100 mL (20 °C) 31.9 g/100 mL (40 °C)
Solubility in methyl acetate	7.81 g/100 g
Solubility in ethyl acetate	10.7 g/100 g
Vapor pressure	0.051 mPa (25 °C) 1.08 kPa (200 °C) 28.06 kPa (300 °C)
Acidity (pKa)	4.75
Magnetic susceptibility (χ)	-198.6·10−6 cm3/mol
Refractive index (nD)	1.43 (70 °C)
Viscosity	7.8 cP (70 °C)
Thermochemistry
Specific heat capacity (C)	463.36 J/mol·K
Std molar entropy (So298)	452.37 J/mol·K
Std enthalpy of formation (ΔfHo298)	-892 kJ/mol
Std enthalpy of combustion (ΔcHo298)	10030.6 kJ/mol
Hazards
GHS pictograms
GHS signal word	Warning
GHS hazard statements	H319
GHS precautionary statements	P305+351+338
EU classification (DSD)	Xi
R-phrases	R36/37/38
S-phrases	S26
NFPA 704	1 1 0
Flash point	206 °C (403 °F; 479 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Palmitic acid, or hexadecanoic acid in IUPAC nomenclature, is the most common saturated fatty acid found in animals, plants and microorganisms. Its chemical formula is CH₃(CH₂)₁₄COOH. As its name indicates, it is a major component of the oil from the fruit of oil palms (palm oil). Palmitic acid can also be found in meats, cheeses, butter, and dairy products. Palmitate is a term for the salts and esters of palmitic acid. The palmitate anion is the observed form of palmitic acid at physiologic pH (7.4).

Aluminium salts of palmitic acid and naphthenic acid were combined during World War II to produce napalm. The word "napalm" is derived from the words naphthenic acid and palmitic acid.

Palmitic acid was discovered by Edmond Frémy in 1840, in saponified palm oil. This remains the primary industrial route for its production, with the triglycerides (fats) in palm oil being hydrolysed by high temperature water (above 200 °C or 390 °F), and the resulting mixture fractionally distilled to give the pure product.

Palmitic acid is naturally produced by a wide range of other plants and organisms, typically at low levels. It is naturally present in butter, cheese, milk, and meat , as well as cocoa butter, soybean oil, and sunflower oil. The cetyl ester of palmitic acid (cetyl palmitate) occurs in spermaceti.