Flammable above 38℃, combustible above 40℃.
Distillation can increase the alcohol concentration to about 73% at most, because ethanol and water form an azeotropic mixture. ?
Medicinal alcohol is only alcohol with a concentration of 70% (volume ratio) and can be chemically synthesized. ? In fact, in chemistry, ethanol is commonly known as alcohol. Even 1% ethanol can be an alcoholic solution.
Ethanol is a flammable, volatile, colorless and transparent liquid at normal temperature and pressure, and its toxicity is low, so pure liquid cannot be directly drunk. It has a special fragrance and is slightly irritating; Slightly sweet with pungent taste.
Flammable, its vapor can form an explosive mixture with air and can be miscible with water in any proportion. It is miscible with most organic solvents such as chloroform, ether, methanol and acetone, and its relative density is (D 15.56) 0.85438+06.
Ethanol is widely used. It can be used to make acetic acid, beverages, spices, dyes, fuels and so on. Ethanol with volume fraction of 70%~75% is also a commonly used disinfectant in medical treatment, which is widely used in national defense chemical industry, medical and health care, food industry and industrial and agricultural production.
Extended data:
The content of pure alcohol in alcohol aqueous solution is its concentration, and the concentration of alcohol aqueous solution is calculated by volume percentage in China. As usual, 50% alcohol means that 100 volume of alcohol solution contains 50 volumes of pure alcohol at 20℃. Calculation formula:
Alcohol capacity = (pure alcohol capacity/total alcohol solution capacity) × 100%
Alcohol = capacity × 100
Ethanol can also be oxidized into acetic acid by potassium permanganate, which turns purple into colorless.
Ethanol can also react with acidic potassium dichromate solution. When ethanol vapor enters the silica gel containing acidic potassium dichromate solution, it can be seen that the silica gel changes from orange red to gray green. This reaction can be used to test whether the driver is drunk driving (drunk driving).
According to the raw materials used in production, it can be divided into starch raw material fermented alcohol, molasses raw material fermented alcohol and sulfite pulp waste liquid fermented to produce alcohol.
Starch raw materials ferment alcohol (generally, starch-containing raw materials such as potatoes, cereals and wild plants hydrolyze starch into glucose under the action of microorganisms, and then further ferment by yeast to produce alcohol).
Fermentation of alcohol by molasses (directly using sugar in molasses, diluting and sterilizing, adding some nutrients, and producing alcohol by yeast fermentation).
Fermentation of sulfite pulp waste liquor to produce alcohol (the six-carbon sugar contained in papermaking waste liquor is fermented into alcohol by yeast, and the main product is industrial alcohol. Alcohol made by hydrolyzing sawdust with dilute acid is also useful.
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