Ethanol

Ethanol

Ethanol is easily soluble in water in all proportions with a slight overall decrease in volume when the two are mixed. Absolute ethanol and 95% ethanol are themselves good solvents, somewhat less polar than water and used in perfumes, paints and tinctures. Other proportions of ethanol with water or other solvents can also be used as a solvent. Alcoholic drinks have a large variety of tastes because various flavor compounds are dissolved during brewing. When ethanol is produced as a mixing beverage it is a neutral grain spirit.

Ethanol is used in medical wipes and in most common antibacterial hand sanitizer gels at a concentration of about 62% (percentage by weight, not volume) as an antiseptic. The peak of the disinfecting power occurs around 70% ethanol; stronger and weaker solutions of ethanol have a lessened ability to disinfect. Solutions of this strength are often used in laboratories for disinfecting work surfaces. Ethanol kills organisms by denaturing their proteins and dissolving their lipids and is effective against most bacteria and fungi, and many viruses, but is ineffective against bacterial spores. Alcohol does not act like an antibiotic and is not effective against infections by ingestion. Ethanol in the low concentrations typically found in most alcoholic beverages does not have useful disinfectant or antiseptic properties, internally or externally.

Wine with less than 16% ethanol cannot protect itself against bacteria. Because of this, port is often fortified with ethanol to at least 18% ethanol by volume to halt fermentation for retaining sweetness and in preparation for aging, at which point it becomes possible to prevent the invasion of bacteria into the port, and to store the port for long periods of time in wooden containers that can 'breathe', thereby permitting the port to age safely without spoiling. Because of ethanol's disinfectant property, alcoholic beverages of 18% ethanol or more by volume can be safely stored for a very long time.

Ethanol's hydroxyl group is able to participate in hydrogen bonding. At the molecular level, liquid ethanol consists of hydrogen-bonded pairs of ethanol molecules; this phenomenon renders ethanol more viscous and less volatile than less polar organic compounds of similar molecular weight. In the vapor phase, there is little hydrogen bonding; ethanol vapor consists of individual ethanol molecules.

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