Alcohols are derivatives of hydrocarbons in the molecule of which one or more hydrogens is replaced by a hydroxyl group (OH). Lower alcohols are dissolved in all proportions in water. Alcohols form esters with acids. Hydrogen of the hydroxyl group may be substituted. So, under the action of metallic sodium, alcoholates are formed. In the process of hydrolysis, alcoholates decompose to water and caustic soda.
Primary alcohols are well oxidized to form aldehydes. Aldehydes are organic compounds that do not have OH groups and do not give esters; during further oxidation, they decompose into acids with fewer carbon atoms. In the process of dehydration of alcohols , unsaturated hydrocarbons are obtained. Aliphatic alcohols act on the body, in general, narcotically. The strength of alcohol depends on their physical properties. When comparing monohydric and polyhydric alcohols, it was noted that the effect of the latter is weakened, and sometimes completely lost, i.e. an increase in the number of hydroxyls in the molecule reduces the pharmacological effect, for example, glycerol does not have a noticeable narcotic effect.
Ethyl alcohol production
Alcohol for medical purposes is obtained by fermentation of sugary substances. Fermented carbohydrates are rye, potatoes, maize, as well as other plant materials. Today, a number of intermediate stages of alcoholic fermentation are known . At the distillery, the incoming material (potatoes, etc.) is first washed from the ground and dirt, and then loaded into a special steamer, where steam is released under pressure in two or three atmospheres. Starch found in potatoes, while turning into a paste. The resulting mass is transferred to the mash vat and there, with energy stirring, cooled to 50 degrees. Malt is added to it at a concentration of up to 10% by weight of the potato. Malt is prepared by germinating barley. In the process of germination of barley in the grains, the process of formation and accumulation of enzymes, one of which is the amylase enzyme. The specified enzyme hydrolyzes starch to maltose. Then, under the influence of the invertin enzyme, maltose is converted into glucose in the aqueous medium. The latter, under the influence of zymase, turns into ethyl alcohol with the release of carbon dioxide. The process is considered complete when carbon dioxide emission ceases. The resulting liquid is called mash, which contains about 18% alcohol and various intermediate fermentation products - glycerol, ethanal (acetate aldehyde), higher alcohols, esters, etc. Next mash subjected to rectification. First, a mixture is obtained with an alcohol content of about 70%, then the level of the latter is increased to 96%. Ethyl alcohol is passed through activated carbon for final purification.
It is economically feasible to obtain alcohol synthetically - from ethylene, which, when exposed to sulfate acid, produces sulfate-ethyl ether, which decomposes upon exposure to water on ethyl alcohol and sulfate acid. It should be noted that alcohol can be synthesized from acetylene. For this, acetylene is passed through an aqueous solution of sulfate acid, in the presence of a catalyst, it attaches water, passing into ethanal. The aldehyde is distilled off and reduced with hydrogen to alcohol. The alcohol concentration is expressed in degrees, for example, 33 °, 40 °. These degrees indicate how many volumes of alcohol are contained in 100 volume units of this solution.
The following types of alcohol are distinguished:
- raw (92-95 °), not sufficiently purified from fusel oils and aldehydes;
- rectified (95-96 °), practically without impurities;
- absolute - almost anhydrous;
- denatured - raw alcohol, to which natural pyridine nitrogenous bases are added; Used for technical and home use.
Ethyl alcohol is a flammable, transparent liquid with a neutral reaction, an alcoholic smell and a burning taste. Pure alcohol is a good organic solvent. The density of ethyl alcohol depends on its concentration in solutions (for example, 40 - 0.9352, 70 - 0.8677, 96 - 0.8014).
Ethanol use
Weakens or kills microorganisms, especially at concentrations above 60-70%. The drug activates digestion, reflexively enhances the activity of the respiratory center and heart during fainting. It is used externally as a disinfectant, irritant, cooling and refreshing treatment for burns (I and II degrees).