Ethanol 100mL for UV Spectroscopy
C2H6O or C2H5OH, CH3CH2OH or EtOH
Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic chemical compound. It is a simple alcohol with the chemical formula C2H6O. Its formula can be also written as CH3−CH2−OH or C2H5OH (an ethyl group linked to a hydroxyl group), and is often abbreviated as EtOH. It is a volatile, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. It is a psychoactive drug, recreational drug, and the active ingredient in alcoholic drinks. It is naturally produced by the fermentation of sugars by yeasts or via petrochemical processes such as ethylene hydration. It has medical applications as an antiseptic and disinfectant. It is used as a chemical solvent and in the synthesis of organic compounds. Ethanol is a fuel source. Also, it can be dehydrated to make ethylene, an important chemical feedstock.
Moreover, it is used in medical wipes and most commonly in antibacterial hand sanitizer gels as an antiseptic for its bactericidal and anti-fungal effects. Ethanol kills microorganisms by dissolving their membrane lipid bilayer and denaturing their proteins, and is effective against most bacteria, fungi and viruses. However, it is ineffective against bacterial spores, but that can be alleviated by using hydrogen peroxide. A solution of 70% is more effective than pure ethanol because relies on water molecules for optimal antimicrobial activity. Absolute ethanol may inactivate microbes without destroying them because the alcohol is unable to fully permeate the microbe’s membrane. However, it can also be used as a disinfectant and antiseptic because it causes cell dehydration by disrupting the osmotic balance across cell membrane, so water leaves the cell leading to cell death.
This reagent may be administered as an antidote to ethylene glycol poisoning and methanol poisoning. Ethanol serves this process by acting as a competitive inhibitor against methanol and ethylene glycol for alcohol dehydrogenase. Though it has more side effects, ethanol is less expensive and more readily available than fomepizole, which is also used as an antidote for methanol and ethylene glycol poisoning.
Often in high concentrations, is used to dissolve many water-insoluble medications and related compounds. Liquid preparations of pain medications, cough and cold medicines, and mouth washes, for example, may contain up to 25% and may need to be avoided in individuals with adverse reactions to ethanol such as alcohol-induced respiratory reactions. Ethanol is present mainly as an antimicrobial preservative in over 700 liquid preparations of medicine including acetaminophen, iron supplements, ranitidine, furosemide, mannitol, phenobarbital, trimethoprim/sulfamethoxazole and over-the-counter cough medicine.
- CH3CH2OH + NAD+ → CH3CHO + NADH + H+
The resulting intermediate, acetaldehyde, is a known carcinogen, and poses significantly greater toxicity in humans than ethanol itself. Many of the symptoms typically associated with alcohol intoxication — as well as many of the health hazards typically associated with the long-term consumption of ethanol — can be attributed to acetaldehyde toxicity in humans.
The subsequent oxidation of acetaldehyde into acetate is performed by aldehyde dehydrogenase (ALDH) enzymes. A mutation in the ALDH2 gene that encodes for an inactive or dysfunctional form of this enzyme affects roughly 50% of east Asian populations, contributing to the characteristic alcohol flush reaction that can cause temporary reddening of the skin as well as a number of related, and often unpleasant, symptoms of acetaldehyde toxicity. This mutation is typically accompanied by another mutation in the alcohol dehydrogenase enzyme ADH1B in roughly 80% of east Asians, which improves the catalytic efficiency of converting ethanol into acetaldehyde.
Despite alcohol’s psychoactive and carcinogenic properties, it is readily available and legal for sale in most countries. However, there are laws regulating the sale, exportation/importation, taxation, manufacturing, consumption, and possession of alcoholic beverages. The most common regulation is prohibition for minors.
|Dry wood (20% moisture)||~19.5|
(85% ethanol, 15% gasoline)
|Liquefied natural gas||25.3||~55|
(60% propane + 40% butane)
(high-octane gasoline, not jet fuel)
(90% gasoline + 10% ethanol)
|Regular gasoline/petrol||34.8||44.4||min. 91|
|Premium gasoline/petrol||max. 104|
The largest single use of ethanol is as an engine fuel and fuel additive. Brazil in particular relies heavily upon the use of ethanol as an engine fuel, due in part to its role as one of the globe’s leading producers of ethanol. Gasoline sold in Brazil contains at least 25% anhydrous ethanol. Hydrous ethanol (about 95% ethanol and 5% water) can be used as fuel in more than 90% of new gasoline fueled cars sold in the country. Brazilian ethanol is produced from sugar cane, which has relatively high yields (830% more fuel than the fossil fuels used to produce it) compared to some other energy crops. The US and many other countries primarily use E10 (10% ethanol, sometimes known as gasohol) and E85 (85% ethanol) ethanol/gasoline mixtures.
Australian law limits the use of pure ethanol from sugarcane waste to 10% in automobiles. Older cars (and vintage cars designed to use a slower burning fuel) should have the engine valves upgraded or replaced.