Acetic acid CAS#64-19-7
Versatile Solubility – Acetic acid is soluble in water, ethanol, glycerol, ether, and carbon tetrachloride, making it highly adaptable for various industrial and laboratory applications.
Rich Historical and Natural Presence – Naturally occurring in many plants in free or ester form, and with a long history of use in vinegar production, acetic acid has proven safety and practicality across centuries.
Multiple Chemical Properties – As a weak organic acid, it exhibits general acidic characteristics and can undergo esterification with alcohols, enabling diverse chemical synthesis possibilities.
High Purity and Distinct Form – Pure acetic acid is a colorless liquid with a pungent taste, while glacial acetic acid solidifies at low temperatures for specific storage needs.
Acetic acid (AcOH), named after the main component of vinegar, is one of the most important fatty acids. It naturally occurs in many plants, either in free form or as esters, and has the molecular formula CH₃COOH. Vinegar brewing has a history spanning thousands of years, with records in ancient China, while concentrated acetic acid was first successfully produced by Stahl in 1700. Pure acetic acid is a colorless liquid with a pungent odor, melting at 16.6 °C and boiling at 117.9 °C, with a relative density of 1.049 (20/4 °C). It is soluble in water, ethanol, glycerol, ether, and carbon tetrachloride, but insoluble in carbon disulfide. At low temperatures, anhydrous acetic acid solidifies into a form known as glacial acetic acid. Corrosive in nature, it is a weak organic acid with typical acidic properties and can react with alcohols to form esters.
Acetic acid Chemical Properties
| Melting point | 16.2 °C(lit.) |
| Boiling point | 117-118 °C(lit.) |
| Density | 1.049 g/mL at 25 °C(lit.) |
| Vapor density | 2.07 (vs air) |
| Vapor pressure | 11.4 mm Hg ( 20 °C) |
| Refractive index | n20/D 1.371(lit.) |
| FEMA | 2006 | ACETIC ACID |
| Fp | 104 °F |
| Storage temp | Store below +30°C. |
| Solubility | Alcohol: miscible(lit.) |
| Form | Solution |
| Pka | 4.74(at 25℃) |
| Specific Gravity | 1.0492 (20℃) |
| Color | Colorless |
| Odor | Strong, pungent, vinegar-like odor detectable at 0.2 to 1.0 ppm |
| PH | 3.91(1 mM solution);3.39(10 mM solution);2.88(100 mM solution); |
| PH Range | 2.4 (1.0M solution) |
| Odor Threshold | 0.006ppm |
| Odor Type | Acidic |
| Explosive limit | 4-19.9%(V) |
| Water Solubility | miscible |
| λmax | λ: 260 nm Amax: 0.05 |
| λ: 270 nm Amax: 0.02 | |
| λ: 300 nm Amax: 0.01 | |
| λ: 500 nm Amax: 0.01 | |
| Merck | 14,55 |
| JECFA Number | 81 |
| BRN | 506007 |
| Henry's Law Constant | 133, 122, 6.88, and 1.27 at pH values of 2.13, 3.52, 5.68, and 7.14, respectively (25 °C, Hakuta et al., 1977) |
| Dielectric constant | 4.1（2℃） |
| Exposure limits | TLV-TWA 10 ppm ～25 mg/m3) (ACGIH, OSHA, and MSHA); TLV-STEL 15 ppm (37.5 mg/m3) (ACGIH). |
| Stability | Volatile |
| LogP | -0.17 |
| CAS DataBase Reference | 64-19-7(CAS DataBase Reference) |
| NIST Chemistry Reference | Acetic acid(64-19-7) |
| EPA Substance Registry System | Acetic acid (64-19-7) |
Safety Information
| Hazard Codes | C,Xi |
| Risk Statements | 34-42-35-10-36/38 |
| Safety Statements | 26-36/37/39-45-23-24/25 |
| RIDADR | UN 1792 8/PG 2 |
| WGK Germany | 3 |
| RTECS | NN1650000 |
| F | 2001/8/10 |
| Autoignition Temperature | 426 °C |
| TSCA | Yes |
| HazardClass | 8 |
| PackingGroup | II |
| HS Code | 29152100 |
| Hazardous Substances Data | 64-19-7(Hazardous Substances Data) |
| Toxicity | LD50 in rats (g/kg): 3.53 orally (Smyth) |
| IDLA | 50 ppm |
In organic synthesis, acetic acid is a key raw material for producing compounds like acetic anhydride, diethyl malonate, ethyl acetoacetate, halogenated acetic acids, and is also used in pharmaceuticals (e.g., aspirin) and agrochemicals (e.g., pesticide 2,4-D). It is essential in the production of metal acetates—including those of manganese, sodium, lead, aluminum, zinc, and cobalt—which act as catalysts and additives in textile dyeing and leather tanning. For example, aluminum acetate functions as a mordant, disinfectant, and medical astringent; lead acetate is used as a pigment (lead white); and lead tetraacetate serves as a reagent in organic synthesis, capable of oxidizing 1,2-diols to aldehydes or ketones. Sodium and potassium acetates are common biochemical buffers.
In the food industry, acetic acid functions as an acidulant, flavor enhancer, and seasoning. For synthetic vinegar production, it is diluted to 4–5% and combined with various flavoring agents, yielding a flavor similar to alcoholic vinegar while being cost-effective and quick to produce. Acetic acid is highly corrosive, causing skin irritation and blisters, and is classified as a secondary organic acid corrosive substance.
