It is he who helps digest food. Normally, stomach acid is 0.3%.

This is enough to destroy a razor blade. It only takes about a week. The experiments, of course, were carried out outside the human body.

A dangerous object would damage the esophagus, would not stay in the stomach for 7 days.

What other experiments were carried out by scientists and how they added to the list of properties of hydrochloric acid, we will describe further.

Properties of hydrochloric acid

Hydrochloric acid formula It is a mixture of water and hydrogen chloride. Accordingly, the liquid is caustic, which allows it to destroy most substances.

The reagent is colorless. It gives off its scent. It is sour, suffocating. The aroma is sharp and, rather, is characterized as a stink.

If a hydrochloric acid solution technical, it contains impurities of the diatomic and. They give the liquid a yellowish tint.

Unlike, for example, mass of hydrochloric acid in solution cannot exceed 38%.

This is the critical point at which the substance simply evaporates. Both hydrogen chloride and water escape.

In this case, of course, the solution smokes. The maximum concentration is indicated for 20-degree air temperature. The higher the degrees, the faster the evaporation.

The density of 38% acid is just over 1 gram per cubic centimeter.

That is, even a concentrated substance is very watery. If you take a sip of this liquid, you will get burns.

But a weak 0.4% solution can be drunk. Naturally, in small quantities. Diluted acid has almost no smell, and it tastes tart and sour.

Hydrochloric acid interaction with other substances, largely justified by the monobasic composition of the reagent.

This means that only one hydrogen atom is included in the acid formula. This means that the reagent dissociates in water, that is, it dissolves completely.

The remaining substances, as a rule, dissolve already in the acid itself. So, in it all the metals that stand in front of hydrogen in the periodic system decay.

Dissolving in acid, they bind with chlorine. As a result, chlorides are obtained, that is,.

Reaction with hydrochloric acid will take place in most oxides and hydroxides of metals, as well as in them.

The main thing is that the latter are obtained from weaker acids. Salt is considered one of the strongest, put on a par with chamois.

From gases hydrochloric acid reacts violently with ammonia. This produces ammonium chloride. It crystallizes.

The particles are so small, and the reaction is so active, that the chloride rushes up. Outwardly it is smoke.

The reaction product with nitrate is also white. This interaction refers to the qualitatively determining hydrochloric.

The result of the reaction is a curdled precipitate. This is chloride. Unlike ammonium chloride, it rushes down, not up.

The reaction with nitrate is considered qualitative, since it is specific, not characteristic of other one-component acids.

They ignore the noble metals, of which the Argentum belongs. As you remember, it stands in the chemical series after hydrogen and, in theory, should not interact with hydrogen chloride dissolved in water.

Production of hydrochloric acid

hydrochloric acid is released not only in laboratory conditions, but also in nature. The human body is part of it.

But, hydrochloric acid in the stomach has already been discussed. However, this is not the only natural source, and, in the literal sense.

The reagent is found in some geysers and other water outlets of volcanic origin.

As for hydrogen chloride separately, it is part of bischofite, sylvin, halite. All of these are minerals.

Under the word "halite" is hidden ordinary salt, which is eaten, that is, sodium chloride.

Sylvin is chloride, its shape is reminiscent of dice. Bischofite - chloride, is present in abundance on the lands of the Volga region.

All of the listed minerals are suitable for industrial production of the reagent.

However, the most commonly used chloride sodium. Hydrochloric acid obtained when table salt is treated with concentrated sulfuric acid.

The essence of the method is reduced to the dissolution of gaseous hydrogen chloride in water. Two more approaches are based on this.

The first is synthetic. Hydrogen is burned in chlorine. The second is off-gas, that is, passing.

Hydrogen chloride is used, which is simultaneously obtained when working with organic compounds, that is, hydrocarbons.

Off-gas hydrogen chloride is formed during dehydrochlorination and chlorination of organic matter.

The substance is also synthesized during the pyrolysis of organochlorine waste. Chemists call pyrolysis the decomposition of hydrocarbons under conditions of oxygen deficiency.

Associated raw materials for hydrochloric acid can also be used when working with inorganic substances, for example, metal chlorides.

The same sylvin, for example, goes to the production of potash fertilizers. Plants also need magnesium.

Therefore, bischofite does not remain idle. As a result, they produce not only top dressing, but also hydrochloric acid.

The off-gas method displaces other methods for producing hydrochloric acid. The "side" industry accounts for 90% of the produced reagent. We will find out why it is made, where it is used.

The use of hydrochloric acid

Hydrochloric acid is used by metallurgists. The reagent is needed for decapitation of metals.

This is the name of the process of removing scale, rust, oxides and just dirt. Accordingly, private craftsmen also use acid, working, for example, with vintage items that have metal parts.

The reagent will dissolve their surface. There will be no trace of the problematic layer. But back to metallurgy.

In this industry, acid is beginning to be used to extract rare metals from ores.

The old methods are based on the use of their oxides. But, not all of them are easy to handle.

Therefore, the oxides began to be converted into chlorides, and then restored. Now, this is how they get, for example, and.

Since hydrochloric acid is contained in gastric juice, and a solution of low concentration can be drunk, it means that the reagent can also be used in the food industry.

Did you see the E507 additive on the product packaging? Know it's hydrochloric acid. It gives the very sourness and astringency to some cakes, sausages.

But, most often, a food emulsifier is added to fructose, gelatin and citric acid.

E507 is needed not only for taste, but also as an acidity regulator, that is, the Ph of the product.

Hydrochloric acid can be used in medicine. A weak solution of hydrochloric acid is prescribed for patients with low stomach acidity.

It is no less dangerous than elevated. In particular, the likelihood of stomach cancer increases.

The body does not receive useful elements, even if a person takes vitamins and eats properly.

The fact is that for adequate, full-fledged absorption of useful substances, standard acidity is needed.

The last use of the reagent is obvious. Chlorine is obtained from acid. It is enough to evaporate the solution.

Chlorine is used for purification of drinking water, bleaching of fabrics, disinfection, production of plastic compounds, etc.

It turns out, being active and aggressive, hydrochloric acid is necessary for mankind. There is a demand, there is a supply. Let's find out the price of the issue.

hydrochloric acid price

Price product depends on the type. Technical acid is cheaper, purified acid is more expensive. For a liter of the first they ask 20-40 rubles.

The cost depends on the concentration. For a liter of purified reagent they give about 20 rubles more.

The price tag also depends on the container, packaging, form of sale. Acquisition of acid in plastic canisters of 25-40 liters is more profitable.

In the medical field, in retail, the substance is offered in glass.

For 50 milliliters you will give 100-160 rubles. This is the most expensive hydrochloric acid.

Buy a solution of hydrogen chloride in a liter container is also not cheap. The packaging is designed for a private consumer, therefore, they ask for about 400-500 rubles per bottle.

Technical acid in retail is less common, it costs about 100 rubles cheaper. The main one is wholesale.

Buying big companies. It is for them that the prices indicated at the beginning of the chapter are relevant. The giants do not sell at retail.

Accordingly, the cost of a substance in small shops is a reflection of the “appetites” of shop owners.

By the way, about appetite. If the acidity in the stomach is increased, food is digested faster, you want to eat more often.

This leads to thinness, gastritis and ulcers. People with low acidity are prone to slagging, because food “roams” in the stomach for a long time, is poorly absorbed.

This is reflected on the skin, usually in the form of acne and dots. Is there such a problem?

Think not about expensive cosmetics, but about checking the gastrointestinal tract.

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 "smokes" in air, since the escaping gaseous HCl forms tiny droplets of hydrochloric acid with water vapor.

Hydrochloric acid is not flammable, not explosive. It is one of the strongest acids, dissolves (with the release of hydrogen and the formation of salts - chlorides) all metals in the series of voltages up to hydrogen. Chlorides are also formed during the interaction of hydrochloric acid with metal oxides and hydroxides. With strong oxidizing agents, it behaves like a reducing agent.

Salts of hydrochloric acid - chlorides, with the exception of AgCl, Hg2Cl2, are highly soluble in water. Glass, ceramics, porcelain, graphite, fluoroplast 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.

Produced technical hydrochloric acid has a strength of at least 31% HCl (synthetic) and 27.5% HCl (from NaCl). 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 obtain chlorides of various metals, organic intermediates and synthetic dyes, acetic acid, activated carbon, various adhesives, hydrolytic alcohol, and in electroforming. 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 before tanning and dyeing. Hydrochloric acid is used in the textile, food industry, medicine, etc.

Hydrochloric acid plays an important role in the processes of digestion, 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 gummed (coated with a layer of rubber) metal vessels, as well as in plastic containers.

Hydrochloric acid very dangerous for human health. Causes severe burns on contact with skin. Eye contact is especially dangerous.

If hydrochloric acid gets on the skin, it must be washed off immediately with a plentiful stream of water.

The mist and vapors of hydrogen chloride formed when concentrated acid interacts with air are very dangerous. They irritate mucous membranes and the respiratory tract. Prolonged work in an atmosphere of HCl 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, cough.

In the event of a leak or spill, hydrochloric acid can cause significant environmental damage. Firstly, this leads to the release of vapors of the substance 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 a change in the chemical properties of soil and water.

Secondly, it can seep into groundwater, resulting in pollution of inland waters.
Where the water in rivers and lakes has become quite acidic (pH less than 5), fish disappear. When trophic chains are disturbed, the number of aquatic animal species, algae and bacteria is reduced.

In cities, acid precipitation accelerates the destruction of marble and concrete structures, monuments and sculptures. Hydrochloric acid corrodes metals when it comes in contact with metals, and reacts with substances such as bleach, manganese dioxide, or potassium permanganate to form toxic chlorine gas.

In the event of a spill, hydrochloric acid is washed off surfaces with plenty of water or an alkaline solution that neutralizes the acid.

The material was prepared on the basis of information from open sources

Hydrochloric acid (H Cl) hazard class 3

(hydrochloric acid concentrated)

Colorless transparent aggressive non-flammable liquid with a pungent odor of hydrogen chloride. Represents 36% ( concentrated) solution of hydrogen chloride in water. Heavier than water. At a temperature of +108.6 0 С it boils, at a temperature of –114.2 0 С it solidifies. It dissolves well in water in all proportions, "smokes" in air due to the formation of hydrogen chloride with water vapor in mist droplets. Interacts with many metals, metal oxides and hydroxides, phosphates and silicates. When interacting with metals, it releases a flammable gas (hydrogen), in a mixture with other acids, it causes spontaneous combustion of some materials. Destroys paper, wood, fabrics. Causes burns on contact with skin. Exposure to a fog of hydrochloric acid, formed as a result of the interaction of hydrogen chloride with water vapor in the air, causes poisoning.

Hydrochloric acid is used in chemical synthesis, for processing ores, pickling metals. It is obtained by dissolving hydrogen chloride in water. Technical hydrochloric acid is produced with a strength of 27.5-38% by weight.

Hydrochloric acid is transported and stored in rubber-coated (coated with a layer of rubber) metal rail and road tanks, containers, cylinders, which are its temporary storage. Typically, hydrochloric acid is stored in ground cylindrical vertical gummed tanks (50-5000 m 3 volume) at atmospheric pressure and ambient temperature or in 20-liter glass bottles. Maximum storage volumes 370 tons.

Maximum Permissible Concentration (MAC) in the air inhabited items is 0.2 mg / m 3, in the air of the working area of ​​industrial premises 5 mg/m 3. At a concentration of 15 mg / m 3, the mucous membranes of the upper respiratory tract and eyes are affected, a sore throat, hoarseness, cough, runny nose, shortness of breath appear, breathing becomes difficult. At concentrations of 50 mg / m 3 and above, bubbling breathing, sharp pains behind the sternum and in the stomach, vomiting, spasm and swelling of the larynx, and loss of consciousness occur. The concentration of 50-75 mg / m 3 is difficult to tolerate. The concentration of 75-100 mg / m 3 is intolerable. A concentration of 6400 mg/m 3 for 30 minutes is lethal. The maximum allowable concentration when using industrial and civil gas masks is 16,000 mg/m 3 .

When dealing with accidents, associated with the spill of hydrochloric acid, it is necessary to isolate the danger zone, remove people from it, keep to the windward side, and avoid low places. Directly at the accident site and in areas of contamination with high concentrations at a distance of up to 50 m from the spill site, work is carried out in insulating gas masks IP-4M, IP-5 (on chemically bound oxygen) or breathing apparatus ASV-2, DAVS (on compressed air ), KIP-8, KIP-9 (on compressed oxygen) and skin protection products (L-1, OZK, KIKH-4, KIKH-5). At a distance of more than 50 m from the outbreak, where the concentration drops sharply, skin protection products can not be used, and industrial gas masks with boxes of grades V, BKF, as well as civilian gas masks GP-5, GP-7, PDF-2D are used to protect the respiratory organs , PDF-2Sh complete with an additional DPG-3 cartridge or RPG-67, RU-60M respirators with a brand V box.

Owing to the fact that hydrochloric acid "smoke" in air with the formation mist droplets when interacting hydrogen chloride with water vapor, in the air determine the presence hydrogen chloride.

The presence of hydrogen chloride is determined by:

In the air of the industrial zone with a gas analyzer OKA-T-N Cl , gas detector IGS-98-N Cl , a universal gas analyzer UG-2 with a measurement range of 0-100 mg / m 3, a gas detector of industrial chemical emissions GPHV-2 in the range of 5-500 mg / m 3.

In open space - with SIP "KORSAR-X" devices.

Indoors - SIP "VEGA-M"

Neutralize hydrochloric acid and hydrogen chloride vapors the following alkaline solutions:

5% aqueous solution of caustic soda (for example, 50 kg of caustic soda per 950 liters of water);

5% aqueous solution of soda powder (for example, 50 kg of soda in powder per 950 liters of water);

5% aqueous solution of slaked lime (for example, 50 kg of slaked lime per 950 liters of water);

5% aqueous solution of caustic soda (for example, 50 kg of caustic soda per 950 liters of water);

When hydrochloric acid is spilled and there is no bunding or pan, the spill site is fenced off with an earthen rampart, hydrogen chloride vapor is precipitated by setting up a water curtain (water consumption is not standardized), the spilled acid is neutralized to safe concentrations with water (8 tons of water per 1 ton of acid) in compliance with all measures precaution or 5% aqueous alkali solution (3.5 tons of solution per 1 ton of acid) and neutralize 5% aqueous solution of alkali (7.4 tons of solution per 1 tonne of acid).

To spray water or solutions, watering and fire trucks, auto-bottling stations (AC, PM-130, ARS-14, ARS-15), as well as hydrants and special systems available at chemically hazardous facilities are used.

To dispose of contaminated soil at the site of a hydrochloric acid spill, the surface layer of soil is cut to the depth of contamination, collected and transported for disposal using earth-moving vehicles (bulldozers, scrapers, motor graders, dump trucks). Places of cuts are covered with a fresh layer of soil, washed with water for control purposes.

Leader actions: isolate the danger zone within a radius of at least 50 meters, remove people from it, keep to the windward side, avoid low places. Enter the accident zone only in full protective clothing.

Providing first aid:

In the infected area: copious rinsing of eyes and face with water, putting on anti-vogas, urgent withdrawal (export) from the outbreak.

After evacuation from the infected area: warming, rest, rinsing acid from exposed skin and clothing with water, copious eyewash with water, if breathing is difficult, warm the neck area, subcutaneously - 1 ml. 0.1% solution of atropine sulfate. Immediate evacuation to a medical facility.

For safety and ease of use, it is recommended to buy the most dilute acid, but sometimes it has to be diluted even more at home. Be sure to wear body and face protection as concentrated acids cause severe chemical burns. To calculate the required amount of acid and water, you will need to know the molarity (M) of the acid and the molarity of the solution you need to get.

Steps

How to calculate the formula

Explore what you already have. Look for the acid concentration symbol on the packaging or in the task description. Usually this value is indicated as molarity, or molar concentration (briefly - M). For example, 6M acid contains 6 moles of acid molecules per liter. Let's call this initial concentration C1.

• The formula will also use the value V 1. This is the volume of acid we will be adding to the water. We probably won't need the whole bottle of acid, though we don't know the exact amount yet.

1. Decide what the result should be. The required concentration and volume of acid is usually indicated in the text of the chemistry problem. For example, we need to dilute the acid to a value of 2M, and we need 0.5 liters of water. Let us denote the required concentration as C2, and the required volume - as V 2.

   • If you are given other units, first convert them to molarity units (moles per liter) and liters.
   • If you don't know what concentration or volume of acid you need, ask a teacher or someone well versed in chemistry.

2. Write a formula to calculate the concentration. Each time you dilute an acid, you will use the following formula: C 1 V 1 = C 2 V 2. This means that the original concentration of a solution times its volume equals the concentration of the diluted solution times its volume. We know this to be true because the concentration times the volume equals the total acid, and the total acid will remain the same.

   • Using the data from the example, we write this formula as (6M)(V 1)=(2M)(0.5L).

3. Solve equation V 1. The value of V 1 will tell us how much concentrated acid we need to get the desired concentration and volume. Let's rewrite the formula as V 1 \u003d (C 2 V 2) / (C 1), then substitute the known numbers.

   • In our example, we get V 1 =((2M)(0.5L))/(6M). This equals approximately 167 milliliters.

4. Calculate the required amount of water. Knowing V 1, that is, the amount of acid available, and V 2, that is, the amount of solution that you get, you can easily calculate how much water you need. V 2 - V 1 = required volume of water.

   • In our case, we want to get 0.167 liters of acid per 0.5 liters of water. We need 0.5 liters - 0.167 liters \u003d 0.333 liters, that is, 333 milliliters.

5. Put on safety goggles, gloves and a gown. You will need special glasses that will cover your eyes and sides. Wear gloves and a gown or apron to avoid burning your skin and clothes.

   Work in a well ventilated area. If possible, work under the included hood - this will prevent acid vapors from harming you and surrounding objects. If you don't have a hood, open all windows and doors or turn on a fan.

6. Find out where the source of running water is. If acid gets in your eyes or on your skin, you will need to rinse the affected area under cool, running water for 15 to 20 minutes. Do not start work until you find out where the nearest sink is.

   • When rinsing your eyes, keep them open. Look up, down, to the sides so that the eyes are washed from all sides.

7. Know what to do if you spill acid. You can buy a special kit for collecting spilled acid, which will include everything you need, or purchase neutralizers and absorbents separately. The process described below is applicable to hydrochloric, sulfuric, nitric and phosphoric acids. Other acids may require different handling.

   • Ventilate the room by opening windows and doors and turning on the exhaust hood and fan.
   • Apply Little sodium carbonate (baking soda), sodium bicarbonate, or calcium carbonate on the outer edges of the puddle to prevent splashing of acid.
   • Gradually fill the entire puddle towards the center until you have completely covered it with the neutralizing agent.
   • Mix thoroughly with a plastic stick. Check the pH value of the puddle with litmus paper. Add more neutralizing agent if this value exceeds 6-8, and then wash the area with plenty of water.

How to dilute acid

1. Cool the water with people. This should only be done if you will be working with high concentrations of acids, such as 18M sulfuric acid or 12M hydrochloric acid. Pour water into a container, place the container on ice for at least 20 minutes.

   • Most often, water at room temperature is sufficient.

2. Pour distilled water into a large flask. For tasks that require extreme precision (for example, titrimetric analysis), use a volumetric flask. For all other purposes, a regular conical flask will do. The entire required volume of liquid must fit in the container, and there must also be room so that the liquid does not spill.

   • If the capacity of the container is known, there is no need to accurately measure the amount of water.

3. Add a small amount of acid. If you are working with small amounts of water, use a graduated or measuring pipette with a rubber tip. If the volume is large, insert a funnel into the flask and carefully pour the acid in small portions with a pipette.

   • Do not use pipettes in the chemistry lab that require air to be sucked in by mouth.

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 chem. reagents used in biochemical, sanitary-hygienic and clinical diagnostic laboratories. In dentistry, 10% S. solution is used to whiten teeth with fluorosis (see Teeth Whitening). S. to. is used to obtain alcohol, glucose, sugar, organic dyes, chlorides, gelatin and glue, in the farm. industry, in tanning and dyeing leather, saponification of fats, in the production of activated carbon, dyeing of fabrics, etching and soldering of metals, in hydrometallurgical processes for cleaning boreholes from deposits of carbonates, oxides and other sediments, in electroforming, etc.

S. to. for people in contact with it during the production process, it represents a significant occupational hazard.

S. to. was known as early as the 15th century. Her discovery is attributed to him. Alchemist Valentine. 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 S. to. was finally established only in the first half of the 19th century. Davy (N. Davy) and J. Gay-Lussac.

In nature, free S. practically does not occur, however, 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 moist air, it strongly "smokes", forming the smallest 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°. In water, hydrogen chloride dissolves well with the release of heat and the formation of S. to .; its solubility in water (g/100 g H2O): 82.3 (0°), 72.1 (20°), 67.3 (30°), 63.3 (40°), 59.6 (50° ), 56.1 (60°).

Page to. represents colorless transparent liquid with a sharp smell of hydrogen chloride; impurities of iron, chlorine, or other substances stain S. to. in a yellowish-greenish color.

Approximate value of S.'s concentration to. in percent can be found if beats. S.'s weight to. reduce by one and multiply the resulting number by 200; e.g., if weight S. to. 1.1341, then its concentration is 26.8%, i.e. (1.1341 - 1) 200.

S. to. chemically very active. It dissolves with the release of hydrogen all metals that have a negative normal potential (see Physico-chemical potentials), converts many metal oxides and hydroxides into chlorides, and releases free acids from salts such as phosphates, silicates, borates, etc.

In a mixture with nitric acid (3:1), the so-called. aqua regia, S. to. reacts with gold, platinum and other chemically inert metals, forming complex ions (AuC14, PtCl6, etc.). Under the influence of oxidizers S. to. is oxidized to chlorine (see).

S. to. reacts with many organic substances, for example, proteins, carbohydrates, etc. Some aromatic amines, natural and synthetic alkaloids, and other basic organic compounds form salts with S. to. Paper, cotton, linen, and many artificial fibers are destroyed by S. to.

The main method for 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 ways to obtain hydrogen chloride are chlorination of organic compounds, dehydrochlorination of organic chlorine derivatives and hydrolysis of certain inorganic compounds with the elimination of hydrogen chloride. Less often, in the lab. practice, they use the old method of producing hydrogen chloride by the interaction of common salt with sulfuric acid.

A characteristic reaction to S. to. and its salts is the formation of a white cheesy precipitate of silver chloride AgCl, soluble in excess aqueous ammonia:

HCl + AgN03 - AgCl + HN03; AgCl + 2NH4OH - [Ag (NHs)2] Cl + + 2H20.

Store S. to. in glassware with ground stoppers in a cool room.

In 1897, IP Pavlov found 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 to. consists in the transfer of H+ ions by a specific carrier to the outer surface of the apical membrane of the intracellular tubules of parietal cells and in their entry after additional conversion into gastric juice (see). C1~ ions from the blood penetrate into the parietal cell while simultaneously transferring the bicarbonate ion HCO2 in the opposite direction. Due to this, C1 ~ ions enter the parietal cell against the concentration gradient and from it into the gastric juice. The parietal cells secrete a solution

Page to., concentration to-rogo makes apprx. 160 mmol!l.

Bibliography: Volfkovich S. I., Egorov A. P. and Epshtein 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, Moscow, 1977; Fundamentals of forensic medicine, ed. N. V. Popova, p. 380, M.-L., 1938; Radbil O. S. Pharmacological bases for the treatment of diseases of the digestive system, p. 232, M., 1976; Rem and G. Course of inorganic chemistry, trans. from German, vol. 1, p. 844, M., 1963; Guidelines for forensic medical examination of poisonings, ed. R. V. Berezhnoy and others, p. 63, M., 1980.

N. G. Budkovskaya; N. V. Korobov (farm.), A. F. Rubtsov (court.).