| Acetone[1] | |
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| IUPAC name | Propanone |
| Other names | β-ketopropane Dimethyl ketone, dimethylformaldehyde, DMK |
| Identifiers | |
| CAS number | 67-64-1 |
| RTECS number | AL31500000 |
| SMILES |
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| InChI |
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| ChemSpider ID | |
| Properties | |
| Molecular formula | C3H6O |
| Molar mass | 58.08 g mol−1 |
| Appearance | Colorless liquid |
| Density | 0.79 g/cm³, liquid |
| Melting point |
−94.9 °C, 178 K, -139 °F |
| Boiling point |
56.53 °C, 330 K, 134 °F |
| Solubility in water | miscible |
| Viscosity | 0.32 cP at 20 °C |
| Structure | |
| Molecular shape | trigonal planar at C=O |
| Dipole moment | 2.91 D |
| Hazards | |
| MSDS | External MSDS |
| EU classification |  F Xi |
| NFPA 704 |
 3
1
0
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| R-phrases | R11, R36, R66, R67 |
| S-phrases | (S2), S9, S16, S26 |
| Flash point | -17 °C |
| Autoignition temperature |
465 °C |
| Related compounds | |
| Related solvents | Water Ethanol Isopropanol Toluene |
| Supplementary data page | |
| Structure and properties |
n, εr, etc. |
| Thermodynamic data |
Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references |
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Acetone (also known as propanone, dimethyl ketone, 2-propanone, propan-2-one, dimethylformaldehyde and β-ketopropane) is a colorless, mobile, flammable liquid. It is the simplest example of the ketones. Acetone is miscible with water, ethanol, ether, etc., and itself serves as an important solvent. The most familiar household uses of acetone are as the active ingredient in nail polish remover and to thin some paints. Acetone is also used to make plastic, fibers, drugs, and other chemicals. In addition to being manufactured as a chemical, acetone is also found naturally in the environment, including in small amounts in the human body.
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Acetone is produced primarily in the cumene process. Previously, acetone was produced by the dry distillation of acetates, for example calcium acetate. During World War I a new process of producing acetone through bacterial fermentation was developed by Chaim Weizmann, later the first president of Israel, in order to help the British war effort. This Acetone Butanol Ethanol process was abandoned due to the small yield of Acetone Butanol compared to the organic waste.
Small amounts of acetone are produced in the body by the decarboxylation of ketone bodies.
Acetone is often the primary (or only) component in nail polish remover. Ethyl acetate, another organic solvent, is sometimes used as well. Acetone is also used as a superglue remover. It can be used for thinning and cleaning fiberglass resins and epoxies. It is a strong solvent for most plastics and synthetic fibres.
It is ideal for thinning fiberglass resin, cleaning fiberglass tools and dissolving two-part epoxies and superglue before hardening. A heavy-duty degreaser, it is useful in the preparation of metal prior to painting; it also thins polyester resins, vinyl and adhesives. It easily removes residues from glass and porcelain. In biological research contexts, buffers that contain acetone (such as citrate-buffered formalin) use the acetone to lyse cells for further experimentation.
Additionally, acetone is extremely effective when used as a cleaning agent when dealing with permanent markers.
Acetone can also dissolve many plastics, including those used in Nalgene bottles made of polystyrene, polycarbonate and some types of polypropylene.[2]
In the laboratory, acetone is used as a polar aprotic solvent in a variety of organic reactions, such as SN2 reactions. The use of acetone solvent is also critical for the successful Jones oxidation. Technical grade acetone is inexpensive. Because of acetone's medium polarity, it dissolves a wide range of compounds. Thus, it is commonly loaded into squeeze bottles and used as a general solvent in rinsing laboratory glassware.
Though flammable itself, acetone is also used extensively for the safe transporting and storing of acetylene in the mining industry. Vessels containing a porous material are first filled with acetone followed by acetylene, which dissolves into the acetone. One liter of acetone can dissolve around 250 liters of acetylene.[3][4]
An important industrial use for acetone involves its reaction with phenol for the manufacture of bisphenol A. Bisphenol A is an important component of many polymers such as polycarbonates, polyurethanes and epoxy resins. Acetone has also been used in the manufacture of cordite.
Some automotive enthusiasts add acetone at around 1 part in 500 to their fuel, following claims of dramatic improvement in fuel economy and engine life.[5] This practice is controversial as the body of systematic testing shows that acetone has no measurable effect or may in fact reduce engine life by adversely affecting fuel system parts.[6][7][8] Debates on this subject and the perennial claims of a "Big Oil" cover-up intensified when the practice was addressed on the popular American TV show MythBusters in 2006, and shown to have negative effect in the televised fuel economy test.[9]
Acetone is also used as a drying agent, due to the readiness with which it mixes with water, and its volatility.
It can be used as an artistic agent; when rubbed on the back of a laser print or photocopy placed face-down on another surface and burnished firmly, the toner of the image is allowed to transfer to the destination surface.
Acetone can be cooled with dry ice to -78 °C without freezing; acetone/dry ice baths are commonly used to conduct reactions at low temperatures.
Acetone is fluorescent under ultraviolet light, and acetone vapor may be used as a fluorescent tracer in fluid flow experiments.[10]
The most common hazard associated with acetone is its extreme flammability. It auto-ignites at a temperature of 465 °C (869 °F). At temperatures greater than acetone's flash point of -20 °C (-4 °F), air mixtures of between 2.5% and 12.8% acetone, by volume, may explode or cause a flash fire. Vapors can flow along surfaces to distant ignition sources and flash back. Static discharge may also ignite acetone vapors.[11]
When oxidized, acetone forms acetone peroxide as a by-product, which is a highly unstable compound. It may be formed accidentally, e.g. when waste hydrogen peroxide is poured into waste solvent containing acetone. Acetone peroxide is more than ten times as friction and shock sensitive as nitroglycerin. Due to its instability, it is rarely used, despite its easy chemical synthesis.
Acetone is believed to exhibit only slight toxicity in normal use, and there is no strong evidence of chronic health effects if basic precautions are followed.[12]
At very high vapor concentrations, acetone is irritating and, like many other solvents, may depress central nervous system. It is also a severe irritant on contact with eyes, and a potential pulmonary aspiration risk. In one documented case, ingestion of a substantial amount of acetone led to systemic toxicity, although the patient eventually fully recovered.[13] Some sources estimate LD50 for human ingestion at 1.159 g/kg; LD50 inhalation by mice is given as 44 g per cubic meter, over 4 hours.[14]
Interestingly, acetone has been shown to have anticonvulsant effects in animal models of epilepsy, in the absence of toxicity, when administered in millimolar concentrations.[15] It has been hypothesized that the high fat low carbohydrate ketogenic diet used clinically to control drug-resistant epilepsy in children works by elevating acetone in the brain.[15]
Acetone evaporates rapidly, even from water and soil. Once in the atmosphere, it is degraded by UV light with a 22-day half-life. Acetone dissipates slowly in soil, animals, or waterways since it is sometimes consumed by microorganisms;[16] however, it is a significant issue with respect to groundwater contamination due to its high solubility in water. The LD50 of acetone for fish is 8.3g/l of water (or about 0.8%) over 96 hours, and its environmental half-life is about 1 to 10 days. Acetone may pose a significant risk of oxygen depletion in aquatic systems due to the microbial activity consuming it.[17]