Stearic acid

Stearic acid[1]
Names
Preferred IUPAC name
Octadecanoic acid
Other names
Identifiers
3D model (JSmol)
Beilstein Reference
 608585
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.285
EC Number
  • 200-313-4
Gmelin Reference
 11738
IUPHAR/BPS
KEGG
RTECS number
  • WI2800000
UNII
CompTox Dashboard (EPA)
  • InChI=1S/C18H36O2/c1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-16-17-18(19)20/h2-17H2,1H3,(H,19,20)
    Key: QIQXTHQIDYTFRH-UHFFFAOYSA-N
SMILES
  • CCCCCCCCCCCCCCCCCC(=O)O
Properties
C18H36O2
Molar mass 284.484 g·mol−1
Appearance White solid
Odor Pungent, oily
Density 0.9408 g/cm3 (20 °C)[2]
0.847 g/cm3 (70 °C)
Melting point 69.3 °C (156.7 °F; 342.4 K)[2]
Boiling point 361 °C (682 °F; 634 K)
decomposes
232 °C (450 °F; 505 K)
at 15 mmHg[2]
0.0018 g/100 g (0 °C)
0.0029 g/100 g (20 °C)
0.0034 g/100 g (30 °C)
0.0042 g/100 g (45 °C)
0.0050 g/100 g (60 °C)[3]
Solubility Soluble in
[4]
Solubility in dichloromethane 3.58 g/100 g (25 °C)
8.85 g/100 g (30 °C)
18.3 g/100 g (35 °C)[4]
Solubility in hexane 0.5 g/100 g (20 °C)
4.3 g/100 g (30 °C)
19 g/100 g (40 °C)
79.2 g/100 g (50 °C)
303 g/100 g (60 °C)[4]
Solubility in ethanol 1.09 g/100 mL (10 °C)
2.25 g/100 g (20 °C)
5.42 g/100 g (30 °C)
22.7 g/100 g (40 °C)
105 g/100 g (50 °C)
400 g/100 g (60 °C)[3]
Solubility in acetone 4.73 g/100 g[5]
Solubility in chloroform 15.54 g/100 g[5]
Solubility in toluene 13.61 g/100 g[5]
Vapor pressure 0.01 kPa (158 °C)[2]
0.46 kPa (200 °C)
16.9 kPa (300 °C)[6]
Magnetic susceptibility (χ)
 −220.8·10−6 cm3/mol
Thermal conductivity 0.173 W/m·K (70 °C)
0.166 W/m·K (100 °C)[7]
1.4299 (80 °C)[2]
Structure
B-form = Monoclinic[8]
B-form = P21/a[8]
B-form = Cs
2h[8]
Lattice constant
a = 5.591 Å, b = 7.404 Å, c = 49.38 Å (B-form)[8]
α = 90°, β = 117.37°, γ = 90°
Thermochemistry
501.5 J/mol·K[2][6]
Std molar
entropy (S⦵298)
 435.6 J/mol·K[2]
−947.7 kJ/mol[2]
−11342.4 kJ/mol[9]
Hazards
NFPA 704 (fire diamond)
1
1
0
Flash point 205 °C (401 °F; 478 K)
Lethal dose or concentration (LD, LC):
4640 mg/kg (rats, oral)[10]
21.5 mg/kg (rats, intravenous)[4]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Stearic acid (/ˈstɪərɪk/ STEER-ik, /stiˈærɪk/ stee-ARR-ik) is a saturated fatty acid with an 18-carbon chain.[9] The IUPAC name is octadecanoic acid.[9] It is a soft waxy solid with the formula CH3(CH2)16CO2H.[9] The triglyceride derived from three molecules of stearic acid is called stearin.[9] Stearic acid is a prevalent fatty acid in nature, found in many animal and vegetable fats, but is usually higher in animal fat than vegetable fat. It has a melting point of 69.4 °C (156.9 °F)  °C and a pKa of 4.50.[11]

Its name comes from the Greek word στέαρ "stéar", which means tallow. The salts and esters of stearic acid are called stearates.[9] As its glycerol ester, stearic acid is one of the most common saturated fatty acids found in nature and in the food supply, following palmitic acid.[12][13] Dietary sources of stearic acid include meat, poultry, fish, eggs, dairy products, and foods prepared with fats; beef tallow, lard, butterfat, cocoa butter, and shea butter are rich fat sources of stearic acid.[9][12]

  1. ^ Susan Budavari, ed. (1989). Merck Index (11th ed.). Rahway, New Jersey: Merck & Co., Inc. p. 8761. ISBN 978-0-911910-28-5.
  2. ^ a b c d e f g h Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0.
  3. ^ a b Theneshkumar, S.; Gnanaprakash, D.; N., Nagendra Gandhi (2010). "Supporting Information Solubility and Mass Transfer Coefficient Enhancement of Stearic Acid through Hydrotropy". Journal of Chemical & Engineering Data. 55 (9): 2980–2984. doi:10.1021/je901041n.
  4. ^ a b c d "stearic acid". Chemister.ru. 2007-03-19. Retrieved 2017-06-30.
  5. ^ a b c Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.). D. Van Nostrand Company. p. 677.
  6. ^ a b Octadecanoic 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 2014-06-15)
  7. ^ Vargaftik, Natan B.; et al. (1993). Handbook of Thermal Conductivity of Liquids and Gases (illustrated ed.). CRC Press. p. 318. ISBN 978-0-8493-9345-7.
  8. ^ a b c d von Sydow, E. (1955). "On the structure of the crystal form B of stearic acid". Acta Crystallographica. 8 (9): 557–560. Bibcode:1955AcCry...8..557V. doi:10.1107/S0365110X55001746.
  9. ^ a b c d e f g "Stearic acid". PubChem, US National Library of Medicine. 29 April 2023. Retrieved 5 May 2023.
  10. ^ Science Lab.com. "Stearic acid MSDS" (PDF). Retrieved 2020-09-30.
  11. ^ Loften, J.R.; Linn, J.G.; Drackley, J.K.; Jenkins, T.C.; Soderholm, C.G.; Kertz, A.F. (August 2014). "Invited review: Palmitic and stearic acid metabolism in lactating dairy cows". Journal of Dairy Science. 97 (8): 4661–4674. doi:10.3168/jds.2014-7919. ISSN 0022-0302. PMID 24913651.
  12. ^ a b Hunter, J. E.; Zhang, J.; Kris-Etherton, P. M. (2009). "Cardiovascular disease risk of dietary stearic acid compared with trans, other saturated, and unsaturated fatty acids: A systematic review". American Journal of Clinical Nutrition. 91 (1): 46–63. doi:10.3945/ajcn.2009.27661. PMID 19939984.
  13. ^ Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra "The Lipid Handbook with Cd-Rom. 3rd ed. Boca Raton: CRC Press, 2007. ISBN 0849396883 | ISBN 978-0849396885
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