Isopropyl alcohol

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Isopropyl alcohol
Image:Isopropanol-skeletal.png
General
Systematic name	Propan-2-ol
Other names	2-propanol, isopropanol, Isopropyl alcohol
Molecular formula	C₃H₈O
SMILES	CC(O)C
Molar mass	60.10 g/mol
Appearance	Colorless liquid
CAS number	67-63-0
Properties
Density and phase	0.78 g/cm³, liquid
Solubility in water	Fully miscible
Solubility in brine	Slightly soluble
In ethanol, ether In acetone, toluene	Fully miscible Soluble
Melting point	-89 °C (185 K)
Boiling point	82 °C (355 K)
Acidity (pK_a)	16.5 for H on hydroxyl
Viscosity	2.86 cP at 15 °C 1.77 cP at 30 °C
Dipole moment	1.66 D (gas)
Hazards
MSDS	External MSDS
Main hazards	Flammable
NFPA 704	Image:Nfpa h1.png Image:Nfpa f3.png Image:Nfpa r0.png
Flash point	12 °C
R/S statement	R: 11-36-67 S: 7-16-24/25-26
RTECS number	NT8050000
Supplementary data page
Structure and properties	n, ε_r, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Related alcohols	1-propanol, ethanol, 2-butanol
Other compounds	acetone, propylene, diisopropyl ether, 2-bromopropane
Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references

Isopropyl alcohol or isopropanol is a common name for propan-2-ol, a colorless, flammable chemical compound with a strong odor. It has the chemical formula CH₃CHOHCH₃, and is the simplest example of a secondary alcohol, where the alcohol carbon is attached to two other carbons. It is an isomer of propan-1-ol.

1 Uses
2 Chemistry
3 Safety
4 Medicine/Toxicology
5 External links

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Uses

Sterilizing pads typically contain a 60-70% solution of isopropanol in water. Isopropyl alcohol is also commonly used as a cleaner and solvent in industry. It is also used as a gasoline additive for dissolving water or ice in fuel lines. Isopropanol is the main ingredient in rubbing alcohol. It is used as a disinfectant, and is a common solvent.

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. If the engine tried to combust the water instead of gasoline serious engine problems could result. 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.

It is also a very good cleaning agent and often used for cleaning electronic devices such as contact pins (like those on ROM cartridges), magnetic tape deck and floppy disk drive heads, the lenses of lasers in optical disc drives (e.g. CD, DVD) and removing thermal paste from CPUs. It is also used to clean computer monitors, and used by many music shops to give second-hand or worn records newer looking sheens.

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Chemistry

Isopropyl alcohol forms an azeotrope with water at 87.4% alcohol. It is impossible to dehydrate isopropanol further using standard distillation methods. For this reason, more expensive means, such as using a drying agent, are necessary for production of 100% isopropyl alcohol.

Being a secondary alcohol, isopropanol can be oxidised to acetone. This can be achieved using oxidising agents such as chromic acid, or by dehydrogenation of isopropanol over a heated copper catalyst:

(CH₃)₂CH-OH → (CH₃)₂C=O + H₂

Isopropanol may be converted to 2-bromopropane using phosphorus tribromide, or dehydrated to propylene by heating with sulfuric acid. With sodium hydroxide and a halogen, or with sodium hypochlorite, it undergoes the haloform reaction. This means it would give a positive result for an iodoform test.

Isopropanol is often used as a hydride source in the Meerwein-Ponndorf-Verley reduction.

Like most alcohols, isopropyl alcohol reacts with active metals such as potassium to form alkoxides which can be called isopropoxides. The reaction with aluminium (initiated by a trace of mercury) is used to prepare the catalyst aluminium isopropoxide.

Isopropanol has a maximal absorbance at 204 nm in an ultraviolet-visible spectrum.

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Safety

Isopropyl alcohol is flammable. It should be kept away from heat and open flame.

Isopropyl alcohol is oxidized by the liver into acetone. Symptoms of isopropyl alcohol poisoning include 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.

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Medicine/Toxicology

Isopropyl alcohol does NOT cause an anion gap acidosis (like ethanol or 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, acetone like odor on the breath.

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