Salicylic acid (frae Laitin salix, willow tree, frae the bark o which the substance uised tae be obtained) is a monohydroxybenzoic acid, a teep o phenolic acid an a beta hydroxy acid. It haes the formula C7H6O3. This colourless crystalline organic acid is widely uised in organic synthesis an functions as a plant hormone. It is derived frae the metabolism o salicin. In addeetion tae bein an important active metabolite o aspirin (acetylsalicylic acid), which acts in pairt as a prodrug tae salicylic acid, it is probably best kent for its uise as a key ingredient in topical anti-acne products. The sauts an esters o salicylic acid are kent as salicylates.

Salicylic acid
Skeletal formula o salicylic acid
Skeletal formula o salicylic acid
Baw-an-stick model o salicylic acid
Baw-an-stick model o salicylic acid
Salicylic acid
Names
IUPAC name
2-Hydroxybenzoic acid
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
DrugBank
EC Nummer 200-712-3
KEGG
RTECS nummer VO0525000
UNII
Properties
C7H6O3
Molar mass 138.12 g·mol−1
Appearance colourless tae white crystals
Odour odorless
Density 1.443 g/cm3 (20 °C)[1]
Meltin pynt 158.6 °C (317.5 °F; 431.8 K)
Bylin pynt 200 °C (392 °F; 473 K)
decomposes[2]
211 °C (412 °F; 484 K)
at 20 mmHg[1]
sublimes at 76 °C[3]
1.24 g/L (0 °C)
2.48 g/L (25 °C)
4.14 g/L (40 °C)
17.41 g/L (75 °C)[2]
77.79 g/L (100 °C)[4]
Solubility soluble in ether, CCl4, benzene, propanol, acetone, ethanol, ile o turpentine, toluene
Solubility in benzene 0.46 g/100 g (11.7 °C)
0.775 g/100 g (25 °C)
0.991 g/100 g (30.5 °C)
2.38 g/100 g (49.4 °C)
4.4 g/100 g (64.2 °C)[2][4]
Solubility in chloroform 2.22 g/100 mL (25 °C)[4]
2.31 g/100 mL (30.5 °C)[2]
Solubility in methanol 40.67 g/100 g (−3 °C)
62.48 g/100 g (21 °C)[2]
Solubility in olive ile 2.43 g/100 g (23 °C)[2]
Solubility in acetone 39.6 g/100 g (23 °C)[2]
log P 2.26
Vapour pressur 10.93 mPa[3]
Acidity (pKa) 1 = 2.97 (25 °C)[5]
2 = 13.82 (20 °C)[2]
λmax 210 nm, 234 nm, 303 nm (4 mg % in ethanol)[3]
Refractive index (nD) 1.565 (20 °C)[1]
Thermochemistry
Std enthalpy o
formation
ΔfHo298
-589.9 kJ/mol
Std enthalpy o
combustion
ΔcHo298
3.025 MJ/mol[6]
Hazards
Safety data sheet MSDS
GHS pictograms The corrosion pictogram in the Globally Harmonized Seestem o Classification an Labelling o Chemicals (GHS)The exclamation-mark pictogram in the Globally Harmonized Seestem o Classification an Labellin of Chemicals (GHS)[7]
GHS signal wird Danger
GHS hazard statements H302, H318[7]
GHS precautionary statements P280, P305+351+338[7]
Ee hazard Severe irritation
Skin hazard Mild irritation
NFPA 704
NFPA 704 four-colored diamondFlammability code 1: Must be pre-heatit afore igneetion can occur. Flash pynt ower 93 °C (200 °F). E.g., canola ileHealth code 2: Intense or continued but nae chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroformReactivity code 0: Normally stable, even unner fire exposur condeetions, an is nae reactive wi watter. E.g., liquid nitrogenSpecial hazards (white): no code
1
2
0
Flash pynt 157 °C (315 °F; 430 K)
closed cup[3]
540 °C (1,004 °F; 813 K)[3]
Lethal dose or concentration (LD, LC):
480 mg/kg (mice, oral)
Relatit compoonds
Relatit compoonds
Methyl salicylate,
Benzoic acid,
Phenol, Aspirin,
4-Hydroxybenzoic acid,
Magnesium salicylate,
Choline salicylate,
Bismuth subsalicylate,
Sulfosalicylic acid
Except whaur itherwise notit, data are gien for materials in thair staundart state (at 25 °C [77 °F], 100 kPa).
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Infobox references

References

eedit
  1. a b c Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nt ed.). CRC Press. p. 3.306. ISBN 1439855110.
  2. a b c d e f g h "Archived copy". Archived frae the original on 24 Mey 2014. Retrieved 30 September 2015.CS1 maint: archived copy as title (link)
  3. a b c d e PubChem 338
  4. a b c Seidell, Atherton; Linke, William F. (1952). [Google Books Solubilities of Inorganic and Organic Compounds] Check |url= value (help). Van Nostrand. Retrieved 29 Mey 2014.
  5. Salicyclic acid. Drugbank.ca. Retrieved on 2012-06-03.
  6. http://webbook.nist.gov/cgi/cbook.cgi?ID=C69727&Type=HCOMBS
  7. a b c Sigma-Aldrich Co. Retrieved on 2014-05-23.