Isopropyl alcohol 15434 225778038 2008-07-15T10:32:02Z Rifleman 82 1255637 /* Toxicology */ stop the edit warring. chemists think 15 g is large, the lay public may think it is small. {{Chembox new | Name = Isopropyl alcohol | ImageFileL1 = Isopropanol-skeletal.png | ImageSizeL1 = 100px | ImageNameL1 = Isopropyl alcohol | ImageFileR1 = Isopropanol-3D-vdW.png | ImageSizeR1 = 120px | ImageNameR1 = Isopropanol | IUPACName = Propan-2-ol | OtherNames = 2-Propanol, Isopropanol, Isopropyl alcohol | Section1 = {{Chembox Identifiers | SMILES = CC(O)C | CASNo = 67-63-0 | RTECS = NT8050000 }} | Section2 = {{Chembox Properties | Formula = C<sub>3</sub>H<sub>8</sub>O | MolarMass = 60.10 g/mol | Appearance = Colorless liquid | Density = 0.786 g/cm³, liquid | Solubility = Fully [[miscible]] | MeltingPt = -89 °C (185 K) | BoilingPt = 82.3 °C (355 K) | pKa = 16.5 for H on [[hydroxyl]] | Viscosity = 2.86 c[[Poise|P]] at 15 °C<br>1.96 c[[Poise|P]] at 25 °C<ref name = yaws>{{cite book | title = Chemical Properties Handbook | author = Yaws, C.L. | publisher = [[McGraw-Hill]] | year = 1999}}</ref><br>1.77 c[[Poise|P]] at 30 °C<br>For 187K-500K, viscosity (cP) =10^(-0.7009+(8.4150E+02/T)+(-8.6068E-03*T)+(8.2964E-06*(T^2))) (Temp in K)<ref name = yaws/> | Dipole = 1.66 [[Debye|D]] (gas) }} | Section7 = {{Chembox Hazards | ExternalMSDS = [http://physchem.ox.ac.uk/MSDS/PR/2-propanol.html External MSDS] | MainHazards = Flammable | FlashPt = 12 °C | RPhrases = {{R11}} {{R36}} {{R67}} | SPhrases = {{S7}} {{S16}} {{S24}} {{S25}} {{S26}} }} | Section8 = {{Chembox Related | Function = [[alcohol]]s | OtherFunctn = [[1-Propanol]], [[Ethanol]], [[2-Butanol]]}} }} '''Isopropyl alcohol''' (also '''isopropanol''', '''iso''', '''isopro''', '''[[rubbing alcohol]]''', or the abbreviation '''IPA''') is a common name for '''propan-2-ol''', a [[colorless]], [[flammable]] [[chemical compound]] with a strong [[odor]]. It has the [[molecular formula]] C<sub>3</sub>H<sub>8</sub>O and is the simplest example of a [[Alcohol#Primary.2C secondary.2C and tertiary alcohols|''secondary alcohol'']], where the [[alcohol]] carbon is attached to two other carbons. It is an [[isomer]] of [[Propan-1-ol|propanol]]. ==Production== Isopropyl alcohol is produced by combining water and [[propylene]].<ref>{{cite encyclopedia | title =Isopropyl Alcohol, by John E. Logsdon and Richard A. Loke | encyclopedia =Kirk‑Othmer Encyclopedia of Chemical Technology | publisher =John Wiley & Sons, Inc | date =Article Online Posting Date: December 4, 2000 | accessdate = 2007-08-30 }}</ref> There are two processes for achieving this: indirect [[hydration reaction|hydration]] via the sulfuric acid process and direct hydration. The former process, which can use low quality propylene, predominates in the USA while the latter process, which requires high-purity propylene, is more commonly used in Europe. These processes give predominantly isopropyl alcohol rather than propan-1-ol because the addition of water or [[sulfuric acid]] to propylene follows [[Markovnikov's rule]]. The indirect process reacts propylene with sulfuric acid to form a mixture of sulfate esters. Subsequent [[hydrolysis]] of these esters produces isopropyl alcohol. Direct hydration reacts propylene and water, either in gas or liquid phases, at high pressures in the presence of solid or supported acidic [[catalyst]]s. Both processes require that the isopropyl alcohol be separated from water and other by-products by [[distillation]]. Isopropyl alcohol and water form an [[azeotrope]] and simple distillation gives a material which is 87.9% by weight isopropyl alcohol and 12.1% by weight water.<ref>CRC Handbook of Chemistry and Physics, 44th ed. pp 2143-2184</ref> Pure (anhydrous) isopropyl alcohol is made by [[azeotropic distillation]] of the "wet" isopropyl alcohol using either [[diisopropyl ether]] or [[cyclohexane]] as azeotroping agents. ==Availability== Although isopropanol is sometimes sold as "Isopropyl Rubbing Alcohol, 70% (or 91%)" and "Isopropyl Rubbing Alcohol, 99%", there is no isopropyl alcohol in the [[United States Pharmacopeia]] formula for [[Rubbing alcohol|rubbing alcohol, U.S.P.]] ==Uses== Isopropyl alcohol is cheaply available. Like acetone, it dissolves a wide range of nonpolar compounds. It is also relatively nontoxic and dries quickly. Thus it is used widely as a solvent and as a cleaning fluid (by dissolving lipophilic contaminants such as oil). Examples of this use include cleaning [[electronics|electronic]] devices such as contact pins (like those on [[read-only memory|ROM]] [[cartridge (electronics)|cartridges]]), [[magnetic tape]] deck and [[floppy disk]] drive heads, the lenses of [[laser]]s in [[optical disc]] drives (e.g. [[CD]], [[DVD]]) and removing [[thermal paste]] from [[central processing unit|CPUs]]. It is also used to clean [[liquid crystal display|LCD]] and glass [[computer monitor]] screens (at some risk to the anti-reflection coating of the screen), and used by many music shops to give second-hand or worn [[Gramophone record|records]] newer-looking sheens. It cleans white boards and other unwanted ink related marks very well. Isopropyl alcohol also works well at removing smudges, dirt, and fingerprints from [[cell phones]] and [[PDA]]s. It is effective at removing residual glue from sticky labels. [[Sterilization (microbiology)|Sterilizing]] pads typically contain a 60-70% [[solution]] of isopropanol in [[water (molecule)|water]]. Isopropyl alcohol is also commonly used as a [[cleaner]] and [[solvent]] in industry. Isopropanol is a major ingredient in "dry-gas" [[fuel additive]]. In significant quantities, [[water]] is a problem in fuel tanks as it separates from the gasoline and can freeze in the supply lines at cold temperatures. The isopropanol does not remove the water from the gasoline; rather, the isopropanol solubilizes the water in the gasoline. Once [[soluble]], the water does not pose the same risk as insoluble water as it will no longer accumulate in the supply lines and freeze. Isopropanol is often sold in aerosol cans as a windscreen de-icer. ==Chemistry== Unlike [[ethanol]] or [[methanol]], isopropanol can be separated from aqueous solutions by adding a salt such as [[sodium chloride]], [[sodium sulfate]], or any of several other inorganic salts.<ref>''Merck Index of Chemicals and Drugs'', 9th ed. monograph 5069</ref> The process is colloquially called [[salting out]], and causes concentrated isopropanol to separate into a distinct layer. Being a secondary alcohol, isopropanol can be [[Organic redox reaction|oxidized]] to the [[ketone]] [[acetone]]. This can be achieved using oxidizing agents such as [[chromic acid]], or by [[dehydrogenation]] of isopropanol over a heated copper [[catalyst]]: :2(CH<sub>3</sub>)<sub>2</sub>CH-OH → 2[[Acetone|(CH<sub>3</sub>)<sub>2</sub>C=O]] + [[Hydrogen|H<sub>2</sub>]] Isopropanol may be converted to [[2-bromopropane]] using [[phosphorus tribromide]], or dehydrated to [[propylene]] by heating with [[sulfuric acid]]. Isopropanol is often used as a [[hydride]] source in the [[Meerwein-Ponndorf-Verley reduction]]. Like most alcohols, isopropyl alcohol reacts with active [[metal]]s such as [[potassium]] to form [[alkoxide]]s which can be called ''isopropoxides''. The reaction with [[aluminium]] (initiated by a trace of [[Mercury (element)|mercury]]) is used to prepare the catalyst [[aluminium isopropoxide]]. Isopropanol has a maximal [[absorbance]] at 204 nm in an [[Ultraviolet-visible spectroscopy|ultraviolet-visible]] spectrum. ==Safety== Isopropyl alcohol vapor is heavier than air and is highly [[flammable]] with a very wide combustible range. It should be kept away from heat and open flame. When mixed with air or other oxidizers it can explode through [[deflagration]].<ref name = oxford>{{cite web | url=http://physchem.ox.ac.uk/MSDS/PR/2-propanol.html | publisher = [[Oxford University]] | title=Safety (MSDS) data for 2-propanol |accessdate=2006-09-28}}</ref> Isopropyl alcohol has also been reported to form explosive [[organic peroxide|peroxides]].<ref>{{cite web | publisher = [[Brookhaven National Laboratory]] | title = Chemical Safety Hazard Alert - Isopropanol, Peroxides Result in Explosion & Injury | author = Hess, R. K. | date = 1997-06-09 | url = http://www.bnl.gov/esh/shsd/programs/Program_Area_Chemicals_Hazard_Alert_Isopropanol.asp}}</ref><ref name = oxford/> Like many organic solvents, long term application to the skin can cause [[defatting]]. ==Toxicology== Isopropyl alcohol is oxidized by the liver into [[acetone]]. [[Symptom]]s of isopropyl alcohol poisoning include [[flushing (physiology)|flushing]], [[headache]], [[dizziness]], [[CNS depression]], [[nausea]], [[vomiting]], [[anesthesia]], and [[coma]]. Use in well-ventilated areas and use protective gloves while using. Poisoning can occur from ingestion, inhalation, or absorption. Isopropyl alcohol is about twice as toxic as [[ethanol]], though isopropyl alcohol does not cause an [[anion gap acidosis]] as do [[ethanol]] and [[methanol]]. It produces an elevated [[osmolal gap]], but generally no abnormal anion gap (though this may be seen as a result of [[hypotension]] and [[lactic acidosis]]). Overdoses may cause a fruity odor on the breath as a result of its metabolism to give [[acetone]] which is not further metabolized.<ref>Tiess, D: Z. ges. Hygiene 31, 530-531 (1985)</ref> Isopropyl alcohol is more potent than [[ethanol]] as a CNS depressant, and its metabolite, acetone, is a CNS depressant in its own right. While around 15 g of isopropanol can be fatal if left untreated, it is not nearly as toxic as methanol or [[ethylene glycol]].<ref>Calculated from TDLO listed at [http://physchem.ox.ac.uk/MSDS/PR/2-propanol.html Oxford University MSDS], assuming weight of 70 kg</ref> ==References== <references/> ==External links== * [http://www.bluerhinos.co.uk/molview/indv.php?id=16 Molview from bluerhinos.co.uk] See Propan-2-ol in 3D * [http://www.osha.gov/SLTC/healthguidelines/isopropylalcohol/recognition.html The US government's Occupational Safety and Health Administration's guidelines for isopropyl alcohol.] {{Alcohols}} {{Antiseptics and disinfectants}} [[Category:Alcohols]] [[Category:Alcohol solvents]] [[Category:Oxygenates]] [[da:Isopropylalkohol]] [[de:2-Propanol]] [[el:Ισοπροπανόλη]] [[es:Alcohol isopropílico]] [[fr:Isopropanol]] [[hr:Izopropanol]] [[it:2-propanolo]] [[lv:Izopropanols]] [[ms:Isopropanol]] [[nl:2-propanol]] [[ja:イソプロパノール]] [[no:Isopropanol]] [[pl:Alkohol izopropylowy]] [[pt:Álcool isopropílico]] [[ru:Изопропиловый спирт]] [[sl:Izopropanol]] [[fi:2-propanoli]] [[zh:异丙醇]]