Stearic acid

Stearic acid^[1]
Names
	Preferred IUPAC name Octadecanoic acid
	Other names Stearic acid; C18:0 (Lipid numbers);
Identifiers
CAS Number	57-11-4 ;
3D model (JSmol)	Interactive image;
ChEMBL	ChEMBL46403 ;
ChemSpider	5091 ;
DrugBank	DB03193 ;
ECHA InfoCard	100.000.285
EC Number	200-313-4;
IUPHAR/BPS	3377;
KEGG	C01530;
PubChem CID	5281;
RTECS number	WI2800000;
UNII	4ELV7Z65AP ;
CompTox Dashboard (EPA)	DTXSID8021642 ;
	SMILES CCCCCCCCCCCCCCCCCC(=O)O;
Properties
Chemical formula	C18H36O2
Molar mass	284.484 g·mol−1
Appearance	White solid
Odor	Pungent, oily
Density	0.9408 g/cm3 (20 °C); 0.847 g/cm3 (70 °C)
Melting point	69.3 °C (156.7 °F; 342.4 K)
Boiling point	361 °C (682 °F; 634 K) ; decomposes; 232 °C (450 °F; 505 K); at 15 mmHg
Solubility in water	0.00018 g/100 g (0 °C); 0.00029 g/100 g (20 °C); 0.00034 g/100 g (30 °C); 0.00042 g/100 g (45 °C); 0.00050 g/100 g (60 °C)
Solubility	Soluble in alkyl acetates; alcohols; methyl formate; phenyls; carbon disulfide; carbon tetrachloride;
Solubility in dichloromethane	3.58 g/100 g (25 °C); 8.85 g/100 g (30 °C); 18.3 g/100 g (35 °C)
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)
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)
Solubility in acetone	4.73 g/100 g
Solubility in chloroform	15.54 g/100 g
Solubility in toluene	13.61 g/100 g
Vapor pressure	0.01 kPa (158 °C); 0.46 kPa (200 °C); 16.9 kPa (300 °C)
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)
Refractive index (nD)	1.4299 (80 °C)
Structure
Crystal structure	B-form = Monoclinic
Space group	B-form = P21/a
Point group	B-form = Cs; 2h
Lattice constant	a = 5.591 Å, b = 7.404 Å, c = 49.38 Å (B-form) α = 90°, β = 117.37°, γ = 90°
Thermochemistry
Heat capacity (C)	501.5 J/mol·K
Std molar; entropy (S⦵298)	435.6 J/mol·K
Std enthalpy of; formation (ΔfH⦵298)	−947.7 kJ/mol
Std enthalpy of; combustion (ΔcH⦵298)	−11342.4 kJ/mol
Hazards
NFPA 704 (fire diamond)	1 1 0
Flash point	113 °C (235 °F; 386 K)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	4640 mg/kg (rats, oral); 21.5 mg/kg (rats, intravenous)
	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 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]

^ Susan Budavari, ed. (1989). Merck Index (11th ed.). Rahway, New Jersey: Merck & Co., Inc. p. 8761. ISBN 978-0-911910-28-5.
^ ^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.
^ ^a ^b Ralston, A.W.; Hoerr, C.W. (1942). "The Solubilities of the Normal Saturated Fatty Acids". The Journal of Organic Chemistry. 7 (6): 546–555. doi:10.1021/jo01200a013. PMID 20280727.
^ ^a ^b ^c ^d "stearic acid". Chemister.ru. 2007-03-19. Retrieved 2017-06-30.
^ ^a ^b ^c Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.). D. Van Nostrand Company. p. 677.
^ ^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)
^ 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.
^ ^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.
^ ^a ^b ^c ^d ^e ^f ^g "Stearic acid". PubChem, US National Library of Medicine. 29 April 2023. Retrieved 5 May 2023.
^ Science Lab.com. "Stearic acid MSDS" (PDF). Retrieved 2020-09-30.
^ 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.
^ ^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.
^ 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

[1] Susan Budavari, ed. (1989). Merck Index (11th ed.). Rahway, New Jersey: Merck & Co., Inc. p. 8761. ISBN 978-0-911910-28-5.

[crc-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.

[Ralston-3] Ralston, A.W.; Hoerr, C.W. (1942). "The Solubilities of the Normal Saturated Fatty Acids". The Journal of Organic Chemistry. 7 (6): 546–555. doi:10.1021/jo01200a013. PMID 20280727.

[chemister-4] "stearic acid". Chemister.ru. 2007-03-19. Retrieved 2017-06-30.

[sioc-5] Seidell, Atherton; Linke, William F. (1919). Solubilities of Inorganic and Organic Compounds (2nd ed.). D. Van Nostrand Company. p. 677.

[nist-6] 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.

[csba-8] 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.

[pubchem-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.

[hunter-12] 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.

[lipidhb-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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Names



Preferred IUPAC name Octadecanoic acid
Other names Stearic acid C18:0 (Lipid numbers)
Identifiers
CAS Number	57-11-4^Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL46403^Y
ChemSpider	5091^Y
DrugBank	DB03193^Y
ECHA InfoCard	100.000.285
EC Number	200-313-4
IUPHAR/BPS	3377
KEGG	C01530
PubChem CID	5281
RTECS number	WI2800000
UNII	4ELV7Z65AP^Y
CompTox Dashboard (EPA)	DTXSID8021642
SMILES CCCCCCCCCCCCCCCCCC(=O)O
Properties
Chemical formula	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]
Solubility in water	0.00018 g/100 g (0 °C) 0.00029 g/100 g (20 °C) 0.00034 g/100 g (30 °C) 0.00042 g/100 g (45 °C) 0.00050 g/100 g (60 °C)^[3]
Solubility	Soluble in alkyl acetates alcohols methyl formate phenyls carbon disulfide carbon tetrachloride ^[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]
Refractive index (n_D)	1.4299 (80 °C)^[2]
Structure
Crystal structure	B-form = Monoclinic^[8]
Space group	B-form = P2₁/a^[8]
Point group	B-form = C^s _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
Heat capacity (C)	501.5 J/mol·K^[2]^[6]
Std molar entropy (S^⦵₂₉₈)	435.6 J/mol·K^[2]
Std enthalpy of formation (Δ_fH^⦵₂₉₈)	−947.7 kJ/mol^[2]
Std enthalpy of combustion (Δ_cH^⦵₂₉₈)	−11342.4 kJ/mol^[9]
Hazards
NFPA 704 (fire diamond)	1 1 0
Flash point	113 °C (235 °F; 386 K)
Lethal dose or concentration (LD, LC):
LD₅₀ (median dose)	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