HYDROCHLORIC ACID (hydrochloric acid) - a strong monobasic acid, a solution of hydrogen chloride HCl in water, is one of the most important components of gastric juice; in medicine it is used as a medicine for insufficiency of the secretory function of the stomach. S. to. is one of the most commonly used chemicals. reagents used in biochemical, sanitary and hygienic and clinical diagnostic laboratories. In dentistry, 10% S. solution is used to whiten teeth in case of fluorosis (see Teeth whitening). S. to. is used to produce alcohol, glucose, sugar, organic dyes, chlorides, gelatin and glue, in pharmaceuticals. industry, in tanning and dyeing leather, saponification of fats, in the production of activated carbon, dyeing fabrics, etching and soldering of metals, in hydrometallurgical processes for cleaning boreholes from deposits of carbonates, oxides and other sediments, in electroplating, etc.
S. to. for people who come into contact with it in the production process, represents a significant occupational hazard.
S. k. was known back in the 15th century. Its discovery is attributed to him. alchemist Valentin. For a long time it was believed that S. to. is an oxygen compound of a hypothetical chemical. element muria (hence one of its names - acidum muriaticum). Chem. the structure of the S. k. was finally established only in the first half of the 19th century. Davy (N. Davy) and J. Gay-Lussac.
In nature, free sodium chloride practically does not occur, but its salts sodium chloride (see Table salt), potassium chloride (see), magnesium chloride (see), calcium chloride (see), etc. are very widespread.
Hydrogen chloride HCl under normal conditions is a colorless gas with a specific pungent odor; when released into humid air, it “smoke” strongly, forming tiny droplets of aerosol S. to. Hydrogen chloride is toxic. Weight (mass) of 1 liter of gas at 0° and 760 mm Hg. Art. equal to 1.6391 g, air density 1.268. Liquid hydrogen chloride boils at -84.8° (760 mmHg) and solidifies at -114.2°. Hydrogen chloride dissolves well in water, releasing heat and forming hydrogen chloride; its solubility in water (g/100 g H20): 82.3 (0°), 72.1 (20°), 67.3 (30°), 63.3 (40°), 59.6 (50° ), 56.1 (60°).
S. to. is a colorless transparent liquid with a pungent odor of hydrogen chloride; impurities of iron, chlorine, or other substances color the soda yellowish-greenish.
The approximate value of S. concentration as a percentage can be found if the beat. reduce the weight of the S. by one and multiply the resulting number by 200; for example, if ud. S.'s weight is 1.1341, then its concentration is 26.8%, i.e. (1.1341 - 1) 200.
S. K. is chemically very active. It dissolves with the release of hydrogen all metals that have a negative normal potential (see Physical and chemical potentials), converts many metal oxides and hydroxides into chlorides and releases free compounds from salts such as phosphates, silicates, borates, etc.
In a mixture with nitrogen (3:1), the so-called. aqua regia, S. reacts with gold, platinum and other chemically inert metals, forming complex ions (AuCl4, PtCl6, etc.). Under the influence of oxidizing agents, S. is oxidized to chlorine (see).
S. to. reacts with many organic substances, for example, proteins, carbohydrates, etc. Certain aromatic amines, natural and synthetic alkaloids and other organic compounds of a basic nature form salts with S. to. hydrochlorides. Paper, cotton, linen, and many artificial fibers are destroyed by S. to.
The main method of producing hydrogen chloride is synthesis from chlorine and hydrogen. The synthesis of hydrogen chloride proceeds in accordance with the reaction H2 + 2C1-^2HCl + 44.126 kcal. Other methods for producing hydrogen chloride are the chlorination of organic compounds, dehydrochlorination of organic chlorine derivatives and the hydrolysis of certain inorganic compounds with the elimination of hydrogen chloride. Less often, in the lab. In practice, they use the old method of producing hydrogen chloride by reacting table salt with sulfuric acid.
A characteristic reaction to S. and its salts is the formation of a white cheesy precipitate of silver chloride AgCl, soluble in an excess of aqueous ammonia solution:
HCl + AgN03 - AgCl + HN03; AgCl + 2NH4OH - [Ag (NHs)2] Cl + + 2H20.
Store S. to. in glass containers with ground-in stoppers in a cool room.
In 1897, I.P. Pavlov established that the parietal cells of the gastric glands of humans and other mammals secrete S. to a constant concentration. It is assumed that the mechanism of S.'s secretion consists of the transfer of H+ ions by a specific carrier to the outer surface of the apical membrane of the intracellular tubules of the parietal cells and their entry after additional conversion into gastric juice (see). C1~ ions from the blood penetrate into the parietal cell while simultaneously transporting the bicarbonate ion HCO in the opposite direction. Due to this, C1~ ions enter the parietal cell against the concentration gradient and from it into the gastric juice. Parietal cells secrete solution
S. to., the concentration of which is approx. 160 mmol!l.
Bibliography: Volfkovich S.I., Egorov A.P. and Epstein D.A. General chemical technology, vol. 1, p. 491 and others, M.-L., 1952; Harmful substances in industry, ed. N.V. Lazarev and I.D. Gadaskina, vol. 3, p. 41, L., 1977; Nekrasov B.V. Fundamentals of general chemistry, vol. 1 - 2, M., 1973; Emergency care for acute poisoning, Handbook of toxicology, ed. S. N. Golikova, p. 197, M., 1977; Fundamentals of Forensic Medicine, ed. N.V. Popova, p. 380, M.-L., 1938; Radbil O. S. Pharmacological basis for the treatment of diseases of the digestive system, p. 232, M., 1976; Rem and G. Course of inorganic chemistry, trans. with German, vol. 1, p. 844, M., 1963; Guide to forensic medical examination of poisonings, ed. R.V. Berezhny et al., p. 63, M., 1980.
N. G. Budkovskaya; N. V. Korobov (pharm.), A. F. Rubtsov (judgment).
Hydrochloric acid is a clear, colorless or yellowish liquid without suspended or emulsified particles.
Hydrochloric acid is a solution of hydrogen chloride gas HCl in water. The latter is a hygroscopic, colorless gas with a pungent odor. Typically used concentrated hydrochloric acid contains 36–38% hydrogen chloride and has a density of 1.19 g/cm3. Such an acid smokes in air because gaseous HCl is released from it; When combined with air moisture, tiny droplets of hydrochloric acid are formed. It is a strong acid and reacts vigorously with most metals. However, metals such as gold, platinum, silver, tungsten and lead are practically not etched by hydrochloric acid. Many base metals, when dissolved in acid, form chlorides, for example zinc:
Zn + 2HCl = ZnCl 2 + H 2
Pure acid is colorless, but technical acid has a yellowish tint caused by traces of compounds of iron, chlorine and other elements (FeCl3). Dilute acid containing 10% or less hydrogen chloride is often used. Dilute solutions do not emit HCl gas and do not smoke in either dry or humid air.
Application of hydrochloric acid
Hydrochloric acid is widely used in industry for extracting metals from ores, pickling metals, etc. It is also used in the manufacture of soldering fluid, in the deposition of silver, and as a component of aqua regia.
The scale of use of hydrochloric acid in industry is less than that of nitric acid. This is due to the fact that hydrochloric acid causes corrosion of steel equipment. In addition, its volatile vapors are quite harmful and also cause corrosion of metal products. This must be taken into account when storing hydrochloric acid. Hydrochloric acid is stored and transported in rubberized tanks and barrels, i.e. in vessels whose inner surface is coated with acid-resistant rubber, as well as in glass bottles and polyethylene containers.
Hydrochloric acid is used to produce chlorides of zinc, manganese, iron and other metals, as well as ammonium chloride. Hydrochloric acid is used to clean the surfaces of metals, vessels, and wells from carbonates, oxides and other sediments and contaminants. In this case, special additives are used - inhibitors, which protect the metal from dissolution and corrosion, but do not delay the dissolution of oxides, carbonates and other similar compounds.
HCl is used in the industrial production of synthetic resins and rubbers. It is used as a raw material in the production of methyl chloride from methyl alcohol, ethyl chloride from ethylene, vinyl chloride from acetylene.
Hydrochloric acid poisoning
HCl is poisonous. Poisoning usually occurs through fog formed when gas interacts with water vapor in the air. HCl is also absorbed on the mucous membranes with the formation of acid, causing severe irritation. When working for a long time in an HCl atmosphere, catarrh of the respiratory tract, tooth decay, ulceration of the nasal mucosa, and gastrointestinal disorders are observed. The permissible content of HCl in the air of working premises is no more than 0.005 mg/l. For protection, use a gas mask, safety glasses, rubber gloves, shoes, and an apron.
At the same time, our digestion is impossible without hydrochloric acid; its concentration in gastric juice is quite high. If the acidity in the body is low, then digestion is impaired, and doctors prescribe such patients to take hydrochloric acid before eating.
Household use of hydrochloric acid
Concentrated “hodgepodge” is mixed with water in any proportion for household needs. A strong solution of this inorganic acid can easily clean earthenware plumbing fixtures from limescale and rust, while a weaker solution can remove stains of rust, ink, and berry juice from fabrics.
If you look closely, the “Toilet Duck” toilet bowl cleaner says that it contains hydrochloric acid, so you need to work with it in rubber gloves and protect your eyes from splashes.
In addition, the life of no one is unthinkable without this acid - it is contained in the stomach and it is thanks to it that food that enters the stomach dissolves (digests).
In addition, this acid serves as the first barrier against pathogenic bacteria that enter the stomach - they die in an acidic environment.
Well, people suffering from gastritis with high acidity are also very familiar with this acid. They even reduce its effect so that it does not destroy the walls of the stomach, using special drugs that interact with it and reduce its concentration.
The most popular are preparations containing magnesium and aluminum oxides, for example, Maalox. However, there are also extreme sports enthusiasts who drink baking soda, although it has already been proven that this only leads to temporary relief.
Hydrochloric acid (hydrochloric acid) - an aqueous solution of hydrogen chloride HCl, is a clear, colorless liquid with a pungent odor of hydrogen chloride. Technical acid has a yellowish-green color due to impurities of chlorine and iron salts. The maximum concentration of hydrochloric acid is about 36% HCl; such a solution has a density of 1.18 g/cm3. Concentrated acid “smoke” in air, since the released gaseous HCl forms tiny droplets of hydrochloric acid with water vapor.
Hydrochloric acid is not flammable or explosive. It is one of the strongest acids; it dissolves (with the release of hydrogen and the formation of salts - chlorides) all metals in the voltage series up to hydrogen. Chlorides are also formed when hydrochloric acid reacts with metal oxides and hydroxides. It behaves as a reducing agent with strong oxidizing agents.
Salts of hydrochloric acid - chlorides, with the exception of AgCl, Hg2Cl2, are highly soluble in water. Glass, ceramics, porcelain, graphite, and fluoroplastic are resistant to it.
Hydrochloric acid is obtained by dissolving hydrogen chloride in water, which is synthesized either directly from hydrogen and chlorine or obtained by the action of sulfuric acid on sodium chloride.
The produced technical hydrochloric acid has a strength of at least 31% HCl (synthetic) and 27.5% HCl (from NaCI). A commercial acid is called concentrated if it contains 24% or more HCl; if the HCl content is less, then the acid is called dilute.
Hydrochloric acid is used to produce chlorides of various metals, organic intermediates and synthetic dyes, acetic acid, activated carbon, various adhesives, hydrolytic alcohol, and in electroplating. It is used for etching metals, for cleaning various vessels, casing pipes of boreholes from carbonates, oxides and other sediments and contaminants. In metallurgy, ores are treated with acid; in the leather industry, leather is treated with acid before tanning and dyeing. Hydrochloric acid is used in the textile, food industries, medicine, etc.
Hydrochloric acid plays an important role in the digestive process; it is an integral part of gastric juice. Diluted hydrochloric acid is prescribed orally mainly for diseases associated with insufficient acidity of gastric juice.
Hydrochloric acid is transported in glass bottles or rubberized (rubber-coated) metal vessels, as well as in plastic containers.
Hydrochloric acid very dangerous to human health. Causes severe burns upon contact with skin. Contact with eyes is especially dangerous.
If hydrochloric acid gets on the skin, it must be washed off immediately with plenty of water.
Fog and hydrogen chloride vapors formed when concentrated acid interacts with air are very dangerous. They irritate the mucous membranes and respiratory tract. Prolonged work in an HCl atmosphere causes catarrh of the respiratory tract, tooth decay, clouding of the cornea of the eyes, ulceration of the nasal mucosa, and gastrointestinal disorders.
Acute poisoning is accompanied by hoarseness, suffocation, runny nose, and cough.
In the event of a leak or spill, hydrochloric acid can cause significant environmental damage. Firstly, this leads to the release of substance vapors into the atmospheric air in quantities exceeding sanitary and hygienic standards, which can lead to poisoning of all living things, as well as the appearance of acid precipitation, which can lead to changes in the chemical properties of soil and water.
Secondly, it can leak into groundwater, which can result in contamination of inland waters.
Where the water in rivers and lakes has become quite acidic (pH less than 5), fish disappear. When trophic chains are disrupted, the number of species of aquatic animals, algae and bacteria decreases.
In cities, acid precipitation accelerates the destruction of marble and concrete structures, monuments and sculptures. When it comes into contact with metals, hydrochloric acid causes corrosion, and when it reacts with substances such as bleach, manganese dioxide, or potassium permanganate, it forms toxic chlorine gas.
In the event of a spill, wash hydrochloric acid off surfaces with plenty of water or an alkaline solution that neutralizes the acid.
The material was prepared based on information from open sources
Description of the substance
Hydrochloric acid is an aqueous solution of hydrogen chloride. The chemical formula of this substance is HCl. In water, the mass of hydrogen chloride at its highest concentration cannot exceed 38%. At room temperature, hydrogen chloride is in a gaseous state. To transform it into a liquid state, it must be cooled to minus 84 degrees Celsius, to become a solid - to minus 112 degrees. The density of concentrated acid at room temperature is 1.19 g/cm 3 . This liquid is part of the gastric juice, which ensures the digestion of food. In this state, its concentration does not exceed 0.3%.Properties of hydrochloric acid
Hydrogen chloride solution is chemically harmful, its hazard class is second.
Salt liquid is a strong monobasic acid that can react with a variety of metals, their salts, oxides and hydroxides, it can react with silver nitrate, ammonia, calcium hypochlorite and strong oxidizing agents:
Physical properties and effects on the body
At high concentrations, it is a caustic substance that can cause burns not only to the mucous membranes, but also to the skin. You can neutralize it with a solution of baking soda. When opening containers with a concentrated saline solution, its vapors, coming into contact with moisture in the air, form a condensate of toxic vapors in the form of tiny droplets (aerosol), which irritates the respiratory tract and eyes.
The concentrated substance has a characteristic pungent odor. Technical grades of hydrogen chloride solution are divided into:
red, unrefined, its color is mainly determined by impurities of ferric chloride;
purified, colorless liquid in which the concentration of HCl is about 25%;
fuming, concentrated, liquid with a HCl concentration of 35-38%.
Chemical properties
How do you get it?
The process of producing salt liquid consists of the stages of obtaining hydrogen chloride and absorbing it with water.
Exists three industrial methods producing hydrogen chloride:
synthetic
sulfate
from by-product gases (exhaust gases) of a number of technological processes. The last method is the most common. By-product HCl is typically generated during the dehychlorination and chlorination of organic compounds, the manufacture of potash fertilizers, and the pyrolysis of metal chlorides or organic wastes containing chlorine.
Storage and transportation
Industrial hydrochloric acid is stored and transported in specialized polymer-coated tanks and containers, polyethylene barrels, glass bottles packed in boxes. Hatches of containers and tanks, caps of barrels and bottles must ensure the tightness of the container. The acid solution should not come into contact with metals located in the voltage line to the left of hydrogen, as this can cause explosive mixtures.
Application
in metallurgy for extracting ores, removing rust, scale, dirt and oxides, soldering and tinning;
in the production of synthetic rubbers and resins;
in galvanoplasty;
as an acidity regulator in the food industry;
for the production of metal chlorides;
to produce chlorine;
in medicine for the treatment of insufficient acidity of gastric juice;
as a cleaning and disinfectant.
Today we invite you to talk about the preparation and use of hydrochloric acid solution and the acid itself in particular. It has found wide application in various sectors of human life. It is also used in medicine.
The use of hydrochloric acid in medicine.
Hydrochloric acid promotes the following processes:
equalizes the acid-base balance of the body;
treats oncological diseases;
inhibits the development of malignant tumors;
digests proteins in the stomach.
Treatment of low stomach acidity with hydrochloric acid.
How to prepare a solution of hydrochloric acid and before treating low acidity, you must consult a doctor and consult with him and under no circumstances attempt any self-medication. He will prescribe treatment for you, according to the individual characteristics of your body, as well as taking into account the results of your tests.
In addition to medications with hydrochloric acid, you can take medications that help stimulate the production of hydrochloric acid in the body. In addition, today herbal remedies have been developed (wormwood, peppermint, calamus), which also stimulate the production of hydrochloric acid in the body, which helps increase the level of stomach acidity.
With the help of drugs containing hydrochloric acid, you can prevent stomach cancer, reduce the risk of hepatitis, as well as diseases such as diabetes, psoriasis, rheumatoid arthritis, eczema, cholelithiasis, rosacea, urticaria, asthma and many others.
How to prepare a solution of hydrochloric acid and application.
In order not to wonder how to prepare a solution of hydrochloric acid, we suggest studying the following information that will be useful to you. The prepared solution with hydrochloric acid is sometimes called aqua regia. This cooking recipe was invented by Bolotov and to prepare it we will need the following substances. Add 0.5 cups of grape vinegar to a liter jar of water, then 1-2 teaspoons of sulfuric acid and 1 tablespoon of 38 percent hydrochloric acid, without disturbing this sequence. At the end you need to add 4 tablets of nitroglycerin. Using the resulting solution of hydrochloric acid and other ingredients, it is possible to break down cancer cells that provoke the appearance of a disease such as cancer. As for use, you need to use such a solution three times a day, 1-2 teaspoons, which are diluted in 0.5 glasses of liquid (this can be plain water, tea or coffee) before or after meals. If the disease has taken an acute form, the dose can be increased to 1 tablespoon per half glass of water.
Treatment of hemorrhoids with hydrochloric acid solution.
Due to a sedentary lifestyle, a disease such as hemorrhoids can develop. To treat this disease, traditional medicine is most often used. The use of such a recipe is considered very effective. Take half a glass of water and add 1-2 tablespoons of a 3-5% hydrochloric acid solution. It is recommended to consume the resulting solution half a glass before meals.
Thus, knowing how to prepare a solution of hydrochloric acid, and having information about what it is used for, you have a chance, at home, to be cured of many diseases.