Acetic acid
Acetic acid, or ethanoic acid, (CH3COOH) is a carboxylic acid. It is the main compound of vinegar, other than water.
| Acetic acid | |
|---|---|
 |
 |
 |
 |
| |
Acetic acid[1] | |
Ethanoic acid | |
| Other names | Vinegar (when dilute); Hydrogen acetate; Methanecarboxylic acid[2][3] |
| Identifiers | |
| Abbreviations | AcOH |
| CAS number | |
| PubChem | |
| EC number | 200-580-7 |
| DrugBank | DB03166 |
| KEGG | D00010 |
| MeSH | |
| ChEBI | CHEBI:15366 |
| RTECS number | AF1225000 |
| SMILES | CC(O)=O |
| Beilstein Reference | 506007 |
| Gmelin Reference | 1380 |
| 3DMet | B00009 |
| Properties | |
| Molecular formula | C2H4O2 |
| Molar mass | 60.04 g mol-1 |
| Appearance | Colourless liquid |
| Odor | Pungent/Vinegar-like |
| Density | 1.049 g cm−3 (liquid); 1.27 g cm cm−3 (solid) |
| Melting point |
Expression error: Unrecognized word "to". °C, 289 to 290 K, Expression error: Unrecognized word "to". °F |
| Boiling point | |
| Solubility in water | Miscible |
| log P | -0.28[4] |
| Acidity (pKa) | |
| Basicity (pKb) | 9.24 (basicity of acetate ion) |
| -31.54·10−6 cm3/mol | |
| Refractive index (nD) | 1.371 |
| Viscosity | 1.22 mPa s |
| Dipole moment | 1.74 D |
| Thermochemistry | |
| Std enthalpy of formation ΔfH |
-483.88—483.16 kJ mol−1 |
| Std enthalpy of combustion ΔcH |
-875.50—874.82 kJ mol−1 |
| Standard molar entropy S |
158.0 J K−1 mol−1 |
| Specific heat capacity, C | 123.1 J K−1 mol−1 |
| Pharmacology | |
| ATC code | |
| Hazards | |
| NFPA 704 |
2
3
0
|
| Explosive limits | 4–16% |
| U.S. Permissible exposure limit (PEL) |
TWA 10 ppm (25 mg/m3)[7] |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
It tastes and smells sour; it has no color. Its melting point is 16.5 °C (61.6 °F) and its boiling point is 118.1 °C (244.5 °F). It has a pH of 2.4.
Acetic acid is commonly used as a food additive. It has the E numbers E 260 (acetic acid).
Potassium acetate (E 261), sodium acetate (E 262), and calcium acetate (E 2639) are salts of acetic acid; they are commonly used to preserve food, usually vegetables. In sourdough, ethanol fermentation is used.
Acetic Acid Media
- AceticAcid
- AceticAcid
Deprotonation equilibrium of acetic acid in water
Cyclic dimer of acetic acid; dashed green lines represent hydrogen bonds
Purification and concentration plant for acetic acid in 1884
Reaction of methanol and carbon monoxide in the presence of various catalysts gives acetic acid
References
- ↑ Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 745. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
- ↑ Scientific literature reviews on generally recognised as safe (GRAS) food ingredients. National Technical Information Service. 1974. p. 1.
- ↑ "Chemistry", volume 5, Encyclopædia Britannica, 1961, page 374
- ↑ "acetic acid_msds".
- ↑ Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. pp. 5–88. ISBN 9781498754293.
- ↑ Bordwell, F. G.; Algrim, Donald (1976). "Nitrogen acids. 1. Carboxamides and sulfonamides". The Journal of Organic Chemistry. 41 (14): 2507–2508. doi:10.1021/jo00876a042.
- ↑ NIOSH Pocket Guide to Chemical Hazards. "#0002". National Institute for Occupational Safety and Health (NIOSH).
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