Chemical properties of concentrated hydrochloric acid. The use of hydrochloric acid in medicine

The date: 21.09.2019

- (HCl), water solution hydrogen chloride, a colorless gas with a pungent odor. Obtained by the action of sulfuric acid on common salt, as a by-product of the chlorination of hydrocarbons, or by the reaction of hydrogen and chlorine. Hydrochloric acid is used for… … Scientific and technical encyclopedic Dictionary

Hydrochloric acid- - HCl (SC) (hydrochloric acid, hydrochloric acid, hydrogen chloride) is a solution of hydrogen chloride (HCl) in water, an antifreeze additive. It is a colorless liquid with a pungent odor, without suspended particles. ... ... Encyclopedia of terms, definitions and explanations of building materials

- (hydrochloric acid) solution of hydrogen chloride in water; strong acid. A colorless liquid fuming in air (technical hydrochloric acid is yellowish due to impurities of Fe, Cl2, etc.). Maximum concentration (at 20 .C) 38% by mass, ... ... Big Encyclopedic Dictionary

HYDROCHLORIC ACID- (Acidum muriaticum, Acid, hydrochloricum), a solution of hydrogen chloride (HC1) in water. In nature, it occurs in the water of some sources of volcanic origin, and is also found in gastric juice (up to 0.5%). Hydrogen chloride can be obtained ... Big Medical Encyclopedia

HYDROCHLORIC ACID- (hydrochloric acid, hydrochloric acid) a strong monobasic volatile acid with a pungent odor, an aqueous solution of hydrogen chloride; the maximum concentration is 38% by mass, the density of such a solution is 1.19 g/cm3. Used in... ... Russian encyclopedia of labor protection

HYDROCHLORIC ACID- (hydrochloric acid) HCl aqueous solution of hydrogen chloride, strong monobasic acid, volatile, with a pungent odor; impurities of iron, chlorine stain it yellowish. The concentrated S. to sell contains 37% ... ... Great Polytechnic Encyclopedia

Exist., Number of synonyms: 1 acid (171) ASIS Synonym Dictionary. V.N. Trishin. 2013 ... Synonym dictionary

Modern Encyclopedia

Hydrochloric acid- HYDROGENIC ACID, aqueous solution of hydrogen chloride HCl; a fuming liquid with a pungent odor. Hydrochloric acid is used to obtain various chlorides, pickling metals, processing ores, in the production of chlorine, soda, rubber, etc. ... ... Illustrated Encyclopedic Dictionary

- (hydrochloric acid), a solution of hydrogen chloride in water; strong acid. A colorless liquid "fuming" in air (technical hydrochloric acid is yellowish due to impurities of Fe, Cl2, etc.). Maximum concentration (at 20°C) 38% by mass,… … encyclopedic Dictionary

Hydrochloric acid is an inorganic substance, monobasic acid, one of the strongest acids. Other names are also used: hydrogen chloride, hydrochloric acid, hydrochloric acid.

Properties

Acid in pure form is a colorless and odorless liquid. Technical acid usually contains impurities that give it a slightly yellowish tint. Hydrochloric acid is often referred to as "fuming" because it releases hydrogen chloride vapor, which reacts with atmospheric moisture to form an acid mist.

It dissolves very well in water. At room temperature, the maximum possible mass content of hydrogen chloride is 38%. An acid concentration greater than 24% is considered concentrated.

Hydrochloric acid actively reacts with metals, oxides, hydroxides, forming salts - chlorides. HCl interacts with salts of weaker acids; with strong oxidizing agents and ammonia.

To determine hydrochloric acid or chlorides, a reaction with silver nitrate AgNO3 is used, as a result of which a white cheesy precipitate precipitates.

Safety

The substance is very caustic, corrosive to skin, organic materials, metals and their oxides. In the air, it emits hydrogen chloride vapors, which cause suffocation, burns to the skin, mucous membranes of the eyes and nose, damage the respiratory system, and destroy teeth. Hydrochloric acid belongs to the substances of the 2nd degree of danger (highly dangerous), the MPC of the reagent in the air is 0.005 mg/l. It is possible to work with hydrogen chloride only in filtering gas masks and protective clothing, including rubber gloves, an apron, safety shoes.

If acid is spilled, wash it off large quantity water or neutralized with alkaline solutions. Victims of acid should be taken out of the danger zone, rinse the skin and eyes with water or soda solution, call a doctor.

It is allowed to transport and store a chemical reagent in a glass, plastic container, as well as in a metal container, covered from the inside with a rubber layer. The container must be hermetically sealed.

Receipt

Commercially, hydrochloric acid is produced from hydrogen chloride (HCl) gas. Hydrogen chloride itself is produced in two main ways:
- exothermic reaction of chlorine and hydrogen - in this way a high purity reagent is obtained, for example, for the food industry and pharmaceuticals;
- from accompanying industrial gases - an acid based on such HCl is called off-gas.

It's curious

It is to hydrochloric acid that nature "entrusted" the process of splitting food in the body. The concentration of acid in the stomach is only 0.4%, but this is enough to digest a razor blade in a week!

The acid is produced by the cells of the stomach itself, which is protected from this aggressive substance by the mucous membrane. However, its surface is updated daily to repair damaged areas. In addition to participating in the process of digestion of food, acid also performs protective function, killing pathogens that enter the body through the stomach.

Application

– In medicine and pharmaceuticals – to restore acidity gastric juice with its insufficiency; with anemia to improve the absorption of iron-containing drugs.
- In the food industry, this is a food additive, acidity regulator E507, as well as an ingredient in seltzer (soda) water. Used in the manufacture of fructose, gelatin, citric acid.
- In the chemical industry - the basis for the production of chlorine, soda, sodium glutamate, metal chlorides, for example zinc chloride, manganese chloride, iron chloride; synthesis of organochlorine substances; catalyst in organic synthesis.
- Most of the hydrochloric acid produced in the world is used in metallurgy to clean workpieces from oxides. For these purposes, an inhibited technical acid is used, which contains special inhibitors (retarders) of the reaction, due to which the reagent dissolves oxides, but not the metal itself. Metals are also poisoned with hydrochloric acid; clean them before tinning, soldering, galvanizing.
— Treat the skin before tanning.
- In the mining industry, it is in demand for cleaning boreholes from deposits, for processing ores and rock formations.
— In laboratory practice, hydrochloric acid is used as a popular reagent for analytical studies, for cleaning vessels from hard-to-remove contaminants.
– It is used in the rubber, pulp and paper industry, in ferrous metallurgy; for cleaning boilers, pipes, equipment from complex deposits, scale, rust; for cleaning ceramic and metal products.

- (HCl), an aqueous solution of hydrogen chloride, a colorless gas with a pungent odor. Obtained by the action of sulfuric acid on common salt, as a by-product of the chlorination of hydrocarbons, or by the reaction of hydrogen and chlorine. Hydrochloric acid is used for ... ... Scientific and technical encyclopedic dictionary

HYDROCHLORIC ACID- (hydrochloric acid) solution of hydrogen chloride in water; strong acid. A colorless liquid fuming in air (technical hydrochloric acid is yellowish due to impurities of Fe, Cl2, etc.). Maximum concentration (at 20 .C) 38% by mass, ... ... Big Encyclopedic Dictionary

hydrochloric acid- n., number of synonyms: 1 acid (171) ASIS Synonym Dictionary. V.N. Trishin. 2013 ... Synonym dictionary

HYDROCHLORIC ACID Modern Encyclopedia

hydrochloric acid- (hydrochloric acid), a solution of hydrogen chloride in water; strong acid. A colorless liquid "fuming" in air (technical hydrochloric acid is yellowish due to impurities of Fe, Cl2, etc.). Maximum concentration (at 20°C) 38% by mass,… … encyclopedic Dictionary

Structural formula

True, empirical, or gross formula: HCl

Chemical composition of hydrochloric acid

Molecular weight: 36.461

Hydrochloric acid(also hydrochloric, hydrochloric acid, hydrogen chloride) - a solution of hydrogen chloride (HCl) in water, a strong monobasic acid. Colorless, transparent, caustic liquid, "fuming" in air (technical hydrochloric acid is yellowish due to impurities of iron, chlorine, etc.). At a concentration of about 0.5%, it is present in the human stomach. The maximum concentration at 20 °C is 38% by weight, the density of such a solution is 1.19 g/cm³. Molar mass 36.46 g/mol. Salts of hydrochloric acid are called chlorides.

Physical Properties

The physical properties of hydrochloric acid are highly dependent on the concentration of dissolved hydrogen chloride. When solidified, it gives crystalline hydrates of the compositions HCl H 2 O, HCl 2H 2 O, HCl 3H 2 O, HCl 6H 2 O.

Chemical properties

Interaction with metals standing in a series of electrochemical potentials up to hydrogen, with the formation of a salt and the release of gaseous hydrogen.
Interaction with metal oxides to form a soluble salt and water.
Interaction with metal hydroxides to form a soluble salt and water (neutralization reaction).
Interaction with metal salts formed by weaker acids, such as carbonic.
Interaction with strong oxidizing agents (potassium permanganate, manganese dioxide) with the release of gaseous chlorine.
Interaction with ammonia with the formation of thick white smoke, consisting of the smallest crystals of ammonium chloride.
A qualitative reaction to hydrochloric acid and its salts is its interaction with silver nitrate, which forms a curd precipitate of silver chloride, insoluble in nitric acid.

Receipt

Hydrochloric acid is produced by dissolving hydrogen chloride gas in water. Hydrogen chloride is obtained by burning hydrogen in chlorine, the acid obtained in this way is called synthetic. Hydrochloric acid is also obtained from off-gases - by-product gases generated during various processes, for example, during the chlorination of hydrocarbons. The hydrogen chloride contained in these gases is called off-gas, and the acid thus obtained is called off-gas. In recent decades, the share of off-gas hydrochloric acid in the volume of production has been gradually increasing, displacing the acid obtained by burning hydrogen in chlorine. But hydrochloric acid obtained by burning hydrogen in chlorine contains fewer impurities and is used when high purity is required. In laboratory conditions, a method developed by alchemists is used, which consists in the action of concentrated sulfuric acid on table salt. At temperatures above 550 °C and excess table salt interaction is possible. It is possible to obtain by hydrolysis of chlorides of magnesium, aluminum (hydrated salt is heated). These reactions may not go to completion with the formation of basic chlorides (oxychlorides) of variable composition, for example. Hydrogen chloride is highly soluble in water. So, at 0 °C, 1 volume of water can absorb 507 volumes of HCl, which corresponds to an acid concentration of 45%. However, at room temperature, the solubility of HCl is lower, so 36% hydrochloric acid is usually used in practice.

Application

Industry

It is used in hydrometallurgy and electroforming (etching, pickling), for cleaning the surface of metals during soldering and tinning, for obtaining chlorides of zinc, manganese, iron, and other metals. In a mixture with surfactants, it is used to clean ceramic and metal products (inhibited acid is needed here) from contamination and disinfection.
It is registered in the food industry as an acidity regulator (food additive E507). It is used to make seltzer (soda) water.

The medicine

A natural component of human gastric juice. At a concentration of 0.3-0.5%, usually mixed with the enzyme pepsin, it is administered orally with insufficient acidity.

Features of circulation

Highly concentrated hydrochloric acid is corrosive and causes severe chemical burns. Eye contact is especially dangerous. To neutralize burns, a weak alkali solution, usually baking soda, is used. When opening vessels with concentrated hydrochloric acid, hydrogen chloride vapor, attracting moisture from the air, forms a fog that irritates the eyes and Airways person. Reacts with strong oxidizing agents (chlorine, manganese dioxide, potassium permanganate) to form toxic chlorine gas. In the Russian Federation, the circulation of hydrochloric acid with a concentration of 15% or more is limited.

What is hydrochloric acid solution? It is a compound of water (H2O) and hydrogen chloride (HCl), which is a colorless thermal gas with a characteristic odor. Chlorides are highly soluble and decompose into ions. Hydrochloric acid is the most well-known compound that forms HCl, so we can talk about it and its features in detail.

Description

Hydrochloric acid solution belongs to the class of strong. It is colorless, transparent and caustic. Although technical hydrochloric acid has a yellowish color due to the presence of impurities and other elements. It "smokes" in the air.

It is worth noting that this substance is also present in the body of every person. In the stomach, to be more precise, at a concentration of 0.5%. Interestingly, this amount is enough for total destruction razor blade. The substance will corrode it in just a week.

Unlike the same sulfuric acid, by the way, the mass of hydrochloric acid in solution does not exceed 38%. We can say that this indicator is a “critical” point. If you start to increase the concentration, then the substance will simply evaporate, as a result of which hydrogen chloride will simply evaporate with water. Plus, this concentration is maintained only at 20 ° C. The higher the temperature, the faster the evaporation.

Interaction with metals

Hydrochloric acid solution can enter into many reactions. First of all, with metals that stand before hydrogen in a series of electrochemical potentials. This is the sequence in which the elements go as their characteristic measure, the electrochemical potential (φ 0), increases. This indicator is extremely important in cation reduction half-reactions. In addition, it is this series that demonstrates the activity of metals, which they exhibit in redox reactions.

So, interaction with them occurs with the release of hydrogen in the form of gas and with the formation of salt. Here is an example of a reaction with sodium, a soft alkali metal: 2Na + 2HCl → 2NaCl + H 2 .

With other substances, the interaction proceeds according to similar formulas. This is how the reaction with aluminum, a light metal, looks like: 2Al + 6HCl → 2AlCl 3 + 3H 2.

Reactions with oxides

Hydrochloric acid solution also interacts well with these substances. Oxides are binary compounds of an element with oxygen, having an oxidation state of -2. All known examples are sand, water, rust, dyes, carbon dioxide.

Hydrochloric acid does not interact with all compounds, but only with metal oxides. The reaction also produces a soluble salt and water. An example is the process that occurs between acid and magnesium oxide, an alkaline earth metal: MgO + 2HCl → MgCl 2 + H 2 O.

Reactions with hydroxides

This is the name of inorganic compounds in the compositions of which there is a hydroxyl group -OH, in which the hydrogen and oxygen atoms are connected by a covalent bond. And, since the hydrochloric acid solution only interacts with metal hydroxides, it is worth mentioning that some of them are called alkalis.

So the resulting reaction is called neutralization. Its result is the formation of a weakly dissociating substance (i.e. water) and salt.

An example is the reaction of a small volume of hydrochloric acid solution and barium hydroxide, a soft alkaline earth malleable metal: Ba(OH) 2 + 2HCl = BaCl 2 + 2H 2 O.

Interaction with other substances

In addition to the above, hydrochloric acid can also react with other types of compounds. In particular with:

Metal salts, which are formed by other, weaker acids. Here is an example of one of these reactions: Na 2 Co 3 + 2HCl → 2NaCl + H 2 O + CO 2. Shown here is the interaction with a salt formed by carbonic acid (H 2 CO 3).
Strong oxidizers. With manganese dioxide, for example. Or with potassium permanganate. These reactions are accompanied by the release of chlorine. Here is one example: 2KMnO 4 + 16HCl → 5Cl 2 + 2MnCl 2 + 2KCl + 8H 2 O.
ammonia. It is hydrogen nitride with the formula NH 3 , which is a colorless but pungent gas. The consequence of its reaction with a solution of hydrochloric acid is a mass of thick white smoke, consisting of small crystals of ammonium chloride. Which, by the way, is known to everyone as ammonia (NH 4 Cl). The interaction formula is as follows: NH 3 + HCl → NH 4 CL.
Silver nitrate - an inorganic compound (AgNO 3), which is a salt of nitric acid and silver metal. Due to the contact of a solution of hydrochloric acid with it, a qualitative reaction occurs - the formation of a cheesy precipitate of silver chloride. which does not dissolve in nitric acid. It looks like this: HCL + AgNO 3 → AgCl ↓ + HNO 3.

Getting a substance

Now we can talk about what they do to form hydrochloric acid.

First, by burning hydrogen in chlorine, the main component, gaseous hydrogen chloride, is obtained. which is then dissolved in water. The result of this simple reaction is the formation of a synthetic acid.

This substance can also be obtained from off-gases. These are chemical waste (side) gases. They are formed by a variety of processes. For example, when chlorinating hydrocarbons. The hydrogen chloride in their composition is called off-gas. And the acid thus obtained, respectively.

It should be noted that in last years the share of the off-gas substance in the total volume of its production is increasing. And the acid formed as a result of burning hydrogen in chlorine is displaced. However, in fairness, it should be noted that it contains fewer impurities.

Application in everyday life

Many cleaning products that householders use regularly contain a certain amount of hydrochloric acid solution. 2-3 percent, and sometimes less, but it's there. That is why, putting plumbing in order (washing tiles, for example), you need to wear gloves. Highly acid products can harm the skin.

Another solution is used as a stain remover. It helps to get rid of ink or rust on clothes. But in order for the effect to be noticeable, it is necessary to use a more concentrated substance. A 10% hydrochloric acid solution will do. He, by the way, perfectly removes scale.

It is important to store the substance correctly. Keep acid in glass containers and in places where animals and children cannot reach. Even a weak solution that gets on the skin or mucous membranes can cause a chemical burn. If this happens, immediately rinse the areas with water.

In the field of construction

The use of hydrochloric acid and its solutions is a popular way to improve many building processes. For example, it is often added to concrete mix to increase frost resistance. In addition, this way it hardens faster, and the resistance of the masonry to moisture increases.

Hydrochloric acid is also used as a limestone cleaner. Its 10% solution - The best way fighting dirt and marks on red brick. It is not recommended to use it for cleaning others. The structure of other bricks is more sensitive to the action of this substance.

In medicine

In this area, the substance under consideration is also actively used. Dilute hydrochloric acid has the following effects:

Digests proteins in the stomach.
Stops the development of malignant tumors.
Helps in the treatment of cancer.
Normalizes acid-base balance.
Serves as an effective tool in the prevention of hepatitis, diabetes, psoriasis, eczema, rheumatoid arthritis, cholelithiasis, rosacea, asthma, urticaria and many other ailments.

Did you come up with the idea to dilute the acid and use it inside in this form, and not as part of medicines? This is practiced, but it is strictly forbidden to do this without medical advice and instructions. Having calculated the proportions incorrectly, you can swallow an excess of hydrochloric acid solution, and simply burn your stomach.

By the way, you can still take medications that stimulate the production of this substance. And not just chemicals. The same air peppermint and wormwood contribute to this. You can make decoctions based on them yourself, and drink them for prevention.

Burns and poisoning

As effective as this remedy is, it is dangerous. Hydrochloric acid, depending on the concentration, can cause chemical burns of four degrees:

There is only redness and pain.
There are blisters with a clear liquid and swelling.
Formed necrosis of the upper layers of the skin. Blisters fill with blood or cloudy contents.
The lesion reaches the tendons and muscles.

If the substance somehow got into the eyes, it is necessary to rinse them with water, and then with a soda solution. But in any case, the first thing to do is to call an ambulance.

Acid ingestion is fraught with sharp pains in the chest and abdomen, swelling of the larynx, vomiting bloody masses. As a result, severe pathologies of the liver and kidneys.

And the first signs of poisoning in pairs include a dry frequent cough, choking, damage to the teeth, burning in the mucous membranes and abdominal pain. First urgent care- this is washing and rinsing the mouth with water, as well as access to fresh air. Only a toxicologist can provide real help.