Hydrochloric acid obtaining its chemical properties. Hydrochloric acid is one of the strongest acids and is highly demanded reagent. How does hydrochloric acid affect the skin
Lesson in grade 8 on the topic: Hydrochloric acid and its salts.
purpose : study the chemical properties of hydrochloric acid, and consider the field of application of this acid.
Tasks :
Educational - in the process of research, to study the chemical properties of hydrochloric acid and get acquainted with the qualitative reaction to the chloride ion.
Developing - to develop further skills to compose the equations of chemical reactions; teach to compare, generalize, analyze and draw conclusions.
Educational - to develop cognitive activity through experiment.
Lesson type : a lesson in the assimilation of new knowledge.
Teaching method : explanatory-illustrative, problem-search, practical work, use of ICT.
Organizational forms : conversation, practical work, student messages.
ABOUT equipment and reagents: periodic table of chemical elements, solubility table, stand with test tubes, hydrochloric acid, sodium hydroxide, silver nitrate, copper, magnesium, aluminum, blue litmus, methyl orange, phenolphthalein.
Techniques for enhancing the mental activity of students:
Analysis of educational information.
Disclosure of intersubject connections between chemistry, physics, biology.
Putting hypotheses.
Analysis and drawing up generalized conclusions.
During the classes.
Introduction by the teacher:
The topic of our lesson is "Hydrochloric acid and its properties." (slide 1)
Goethe's words will be the motto of our lesson:
“Just knowing is not everything, you need to be able to use knowledge”. (w. 2)
You will have to show how you can use your knowledge in different situations. First, let's remember what we know about acids. So first question:
What is acid? (a complex substance consisting of hydrogen atoms and an acidic residue).
How many hydrogen atoms can there be in acids? How are they classified according to this criterion? (one-, two-, three-basic). Give examples.
What can replace hydrogen? What is the result? (metals; salts).
Give the definition of salts. (Complex substances, consisting of metal atoms and an acidic residue).
Physical properties:
Concentrated hydrochloric acid (the mass fraction of hydrogen chloride is 37%) is a colorless solution, strongly fuming in humid air, with a pungent odor due to the release of hydrogen chloride. (slide 3 video of the experiment "Properties of fuming hydrochloric acid")
Getting hydrochloric acid:
1.In industry, it is obtained by burning hydrogen in chlorine and dissolving the reaction product in water.
2.In the laboratory H 2 SO 4 +2 NaCl →2 HCl + Na 2 SO 4
This gas dissolves easily in water: up to 450 volumes of hydrogen chloride - in one volume of water. In the test tube, hydrochloric acid is formed - a solution of hydrogen chloride in water.
Chemical properties:
1) Change of color of the indicator (litmus - red)
2) Interacts with metals (if the metal is in the row composed by N.N.Beketov to hydrogen, then hydrogen is released and salt is formed.
An exception HNO 3 (other gases are released)
Mg + 2 HCl → MgCl 2 + H 2 2Al + 6HCl → 2AlCl 3 + 3H 2 Cu + HCl →
Practical work
3) Interacts with basic and amphoteric oxides:
MgO + 2HCl → MgCl 2 + H 2 O ZnO + 2 HCl→ ZnCl 2 + H 2 O
4) Interacts with bases:
HCl + KOH → KCl + H 2 O 3HCl + Al (OH) 3 → AlCl 3 + 3H 2 O
5) Reacts with salts (in accordance with a number of acids, each previous acid can displace the next from the salt), another acid and another salt are formed.
HNO 3
H 2 SO 4 , HCl, H 2 SO 3 , H 2 CO 3 , H 2 S, H 2 SiO 3
────────────────────────
H 3 PO 4
CaCO 3 + 2HCl → CaCl 2 + H 2 O + CO 2
6) Reacts with silver nitrate, precipitates whitewhich does not dissolve in water or acids.
HCl + AgNO 3 → AgCl ↓ + HNO 3
Silver nitrate is a reagent for hydrochloric acid and its salts, i.e. used as a qualitative reaction to recognize chloride ions.
Practical work
7) Reacts with oxidants (MnO 2 , KMO 4 , KClO 3 )
6HCl + KClO 3 \u003d KCl + 3H 2 O + 3Cl 2
Conclusion: in all the reactions we studied, chlorides - salts of hydrochloric acid were obtained.
We turn to the study of salts of hydrochloric acid, which are called chlorides.
Hydrochloric acid salts - chlorides .
Receiving:
1. Interaction of metals with chlorine.
2Fe + 3Cl 2 → 2FeCl 3
2. Interaction of hydrochloric acid with metals.
Mg + 2HCl → MgCl 2 + H 2
3. Interaction of hydrochloric acid with oxides
CaO + 2HCl → CaCl 2 + H 2 O
4. Interaction of hydrochloric acid with hydroxides
Ba (OH) 2 + 2HCl → BaCl 2 + 2H 2 O
5. Interaction of hydrochloric acid with some salts
Pb (NO 3) 2 + 2HCl → PbCl 2 ↓ + 2HNO 3
Most chlorides are water soluble (with the exception of silver, lead, and monovalent mercury chlorides).
Application of hydrochloric acid and its salts:
Hydrochloric acid is a part of gastric juice and promotes the digestion of protein foods in humans and animals.
Hydrogen chloride and hydrochloric acid are used for the production of drugs, dyes, solvents, and plastics.
Application of basic salts of hydrochloric acid:
KCl is a fertilizer, also used in the glass and chemical industries.
HgCl 2 - mercuric chloride - poison, used for disinfection in medicine, for dressing seeds in agriculture.
NaCl - table salt - raw material for the production of hydrochloric acid, sodium hydroxide, hydrogen, chlorine, bleach, soda. It is used in the leather and soap industry, in cooking and canning.
ZnCl 2 - for impregnation of wood against decay, in medicine, during brazing.
AgCl - used in black and white photography, since it has light sensitivity - it decomposes in light to form free silver: 2AgCl \u003d\u003e 2Ag + Cl 2
Repetition and reinforcement assignments
№1. Carry out transformations according to the scheme:
HCl → Cl 2 → AlCl 3 → Al(OH) 3 → Al 2 O 3 → AlCl 3 → Cl 2
# 2. Substances are given:
Zn, Cu, Al, MgO, SiO 2 , Fe 2 O 3 , NaOH, Al(OH) 3 , Fe 2 (SO 4 ) 3 , CaCO 3 , Fe(NO 3 ) 3
Which of these substances will react with hydrochloric acid. Write chemical equations
Number 3. Solve the problem:
How much aluminum will react with an excess of hydrochloric acid to produce 5.6 L of hydrogen (NU)?
D / Z p. 49, task 4-5 p. 169.
Reflection
The teacher (together with the students evaluates the lesson, accepts their suggestions and wishes).
Guys, what have each of you learned in today's lesson?
Have you mastered the concepts: "chlorides", "inhibitor", "qualitative reaction"?
Were there moments of misunderstanding?
Were we able to resolve them during the conversation?
What are the most successful answers of your comrades?
What did you like or dislike in the lesson and why?
Students answer questions, evaluate the completeness of the knowledge gained, and self-assess their work. They identify the most interesting and complete answers, substantiate their point of view.
The degree of fulfillment of educational goals is revealed.
Definition and formula of hydrochloric acid
DEFINITION
Hydrochloric acid (hydrochloric acid, hydrochloric acid, hydrogen chloride) is a solution of hydrogen chloride \\ (\\ mathrm (HCl) \\) in water.
Hydrochloric acid formula
Formula - \\ (\\ \\ mathrm (HCl) \\)
The molar mass is 36.46 g / mol.
Physical properties - colorless caustic liquid, "fumes" in air.
Technical hydrochloric acid has yellow due to the presence of impurities of iron, chlorine and other substances
The maximum concentration in the solution at \\ (\\ 20 ^ (\\ circ) \\ mathrm (C) \\) is 38%, the density of this solution is 1.19 g / cm3. Molar mass 36.46 g / mol.
Hydrochloric acid is a strong monobasic acid, dissociation constant.
Forms salts - chlorides.
Chemical properties of hydrochloric acid
Interacts with metals in the electrochemical range of voltages up to hydrogen with the formation of the corresponding chlorides and hydrogen evolution:
\\ (\\ Z n + 2 H C l \u003d Z n C l_ (2) + H_ (2) \\ uparrow \\)
Interacts with metal oxides to form soluble salts and water:
\\ (\\ M g O + 2 H C l \u003d M g C l_ (2) + H_ (2) O \\)
Interacts with metal hydroxides to form soluble chlorides and water:
\\ (\\ A l (O H) _ (3) +3 H C l \u003d A l C l_ (3) +3 H_ (2) O \\)
Interacts with metal salts formed by weaker acids:
\\ (\\ \\ mathrm (Na) _ (2) \\ mathrm (CO) _ (3) +2 \\ mathrm (HCl) \u003d 2 \\ mathrm (NaCl) + \\ mathrm (H) _ (2) \\ mathrm (O) + \\ mathrm (CO) _ (2) \\ uparrow \\)
Reacts with strong oxidants (potassium permanganate, manganese dioxide), releasing chlorine:
\\ (\\ 2 K M n O_ (4) +16 H C l \u003d 5 C l_ (2) \\ uparrow + 2 M n C l_ (2) +2 K C l + 8 H_ (2) O \\)
Reacts with ammonia to form a thick white smoke consisting of tiny crystals of ammonium chloride:
\\ (\\ N H_ (3) + H C l \u003d N H_ (4) C l \\)
A qualitative reaction to hydrochloric acid and its salt is the reaction with silver nitrate, as a result of which a white curdled precipitate of silver chloride is formed, insoluble in nitric acid:
\\ (\\ H C l + A g N O_ (3) \u003d A g C l \\ downarrow + H N O_ (3) \\)
Hydrochloric acid is obtained by dissolving gaseous hydrogen chloride in water.
Application
Hydrochloric acid is used in hydrometallurgy and electroplating (etching, pickling), for cleaning the surface of metals during soldering and tinning, for obtaining metal chlorides (zinc, manganese, iron, etc.). Mixtures of hydrochloric acid with surfactants are used for cleaning ceramic and metal products from contamination and disinfection.
In the food industry, hydrochloric acid is used as an acidity regulator \\ (\\ \\ mathrm (pH) \\), food additive E507. It is a natural constituent of human gastric juice.
Concentrated hydrochloric acid is a caustic substance that causes severe chemical burns when in contact with the skin. Eye contact is especially dangerous. A weak alkali solution (baking soda) is used to neutralize burns.
Examples of problem solving
Calculate the normality of the hydrochloric acid solution if 19.2 ml of 0.1 N sodium hydroxide solution were consumed for titration of 20 ml of it.
Let's write the equation of the titration reaction:
\\ (\\ H C l + N a O H \u003d N a C l + H_ (2) O \\)
Let's write down the law of equivalents for this titration process:
\\ (\\ V_ (N a O H) \\ cdot N_ (N a O H) \u003d V_ (H C l) \\ cdot N_ (H C l) \\)
Let us express the normal concentration of a hydrochloric acid solution:
\\ (\\ N_ (HC l) \u003d \\ frac (V_ (N a OH) \\ cdot N_ (N a OH)) (V_ (HC l)) \u003d \\ frac (19,2 \\ cdot 0,1) (20) \u003d 0.096 \\)
The normality of the hydrochloric acid solution is 0.096 N.
A solution of hydrochloric acid \\ (\\ \\ mathrm (HCl) \\) with a volume of 1.8 ml (density 1.18 g / ml) with a mass fraction of the substance 36%, diluted with water to 1 liter. Find \\ (\\ _ (1) \\ mathrm (pH) \\) of the resulting solution.
We write the equation for the dissociation of hydrochloric acid:
\\ (\\ H C l \u003d H ^ (+) + C l ^ (-) \\)
Let's find the mass of the initial solution of hydrochloric acid by the formula:
\\ (\\ m \u003d \\ rho \\ cdot V \\)
where \\ (\\ \\ rho \\) is the density of the solution, \\ (\\ \\ mathrm (V) \\) is the volume of the solution.
\\ (\\ m_ (p-p a) \u003d 1.18 \\ cdot 1.8 \u003d 2.124 g. \\)
Find the mass of hydrochloric acid in the solution. Expression for the mass fraction of a substance in a solution:
\\ (\\ \\ omega \u003d \\ frac (m_ (b-b a)) (m_ (p-p a)) \\)
If the solution of hydrochloric acid is 36%, then the mass fraction of hydrochloric acid in it will be equal to 0.36.
Let us express the mass of hydrochloric acid:
\\ (\\ m_ (H C l) \u003d \\ omega \\ cdot m_ (p-p a) \u003d 0.36 \\ cdot 2.124 \u003d 0.765 \\)
Considering that the molar mass of hydrochloric acid is 36.5 g / mol, we calculate the amount of substance \\ (\\ \\ mathrm (HCl) \\) in the solution
\\ (\\ n_ (H C l) \u003d \\ frac (m_ (H C l)) (M_ (H C l)) \u003d \\ frac (0.765) (36.5) \u003d 0.021 \\) mol
Since the initial volume of the solution was diluted with water to 1 liter, we find the molar concentration of the resulting hydrochloric acid solution by the formula:
\\ (\\ C_ (M) (H C l) \u003d \\ frac (n_ (H C l)) (V) \u003d \\ frac (0.021) (1) \u003d 0.021 \\) mol / L
Hydrochloric acid is a strong acid, it dissociates completely in an aqueous solution, therefore, the concentration of hydrogen ions will be equal to the concentration of the acid:
\\ (\\ \\ left \u003d M (H C l) \u003d 0.021 \\) mol / l
the pH of the solution is calculated by the formula:
\\ (\\ p H \u003d -l g \\ left \u003d - \\ lg (0.021) \u003d 1.678 \u003d 1.678 \\)
the pH of the resulting solution is 1.678
Hydrochloric acid is an inorganic substance, a monobasic acid, one of the strongest acids. Other names are also used: hydrogen chloride, hydrochloric acid, hydrochloric acid.
Properties
Pure acid is a colorless and odorless liquid. Technical acid usually contains impurities that give it a slightly yellowish tint. Hydrochloric acid is often called "fuming" because it releases hydrogen chloride vapors that react with moisture in the air to form an acid mist.
Very soluble in water. At room temperature, the maximum possible content of hydrogen chloride by weight is -38%. Acid concentrations greater than 24% are considered concentrated.
Hydrochloric acid actively reacts with metals, oxides, hydroxides, forming salts - chlorides. HCl interacts with salts of weaker acids; with strong oxidants and ammonia.
To determine hydrochloric acid or chlorides, a reaction with silver nitrate AgNO3 is used, as a result of which a white curdled precipitate forms.
Safety engineering
The substance is very corrosive, corrodes the skin, organic materials, metals and their oxides. In the air, it releases 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 hazardous), the maximum concentration limit of the reagent in the air is 0.005 mg / l. You can work with hydrogen chloride only in filtering gas masks and protective clothing, including rubber gloves, an apron, and safety shoes.
When acid spills, it is washed off with plenty of water or neutralized with alkaline solutions. Victims of acid should be removed from the danger area, rinsed skin and eyes with water or soda solution, and call a doctor.
It is allowed to transport and store the chemical reagent in glass, plastic containers, as well as in metal containers covered with a rubber layer on the inside. The container must be hermetically sealed.
Receiving
On an industrial scale, hydrochloric acid is produced from gaseous hydrogen chloride (HCl). Hydrogen chloride itself is produced in two main ways:
- exothermic reaction of chlorine and hydrogen - thus obtaining a reagent of high purity, for example, for the food industry and pharmaceuticals;
- from associated industrial gases - acid based on such HCl is called offgas.
This is curious
It is hydrochloric acid that nature "entrusted" the process of breaking down food in the body. The acid concentration 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 renewed daily to repair damaged areas. In addition to participating in the process of digesting food, acid also performs a protective function, killing pathogens that enter the body through the stomach.
Application
In medicine and pharmaceuticals - to restore the acidity of gastric juice in case of its insufficiency; with anemia to improve the absorption of iron-containing drugs.
- In the food industry, it 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 such as zinc chloride, manganese chloride, ferric chloride; synthesis of organochlorine substances; catalyst in organic syntheses.
- Most of the hydrochloric acid produced in the world is consumed in metallurgy for cleaning billets from oxides. For these purposes, an inhibited technical acid is used, in the composition of which special inhibitors (moderators) of the reaction are introduced, due to which the reagent dissolves the oxides, but not the metal itself. Metals are also etched with hydrochloric acid; clean them before tinning, soldering, electroplating.
- Treat the leather before tanning.
- In the mining industry, it is in demand for cleaning boreholes from sediments, for processing ores and rock formations.
- In laboratory practice, hydrochloric acid is used as a popular reagent for analytical research, for cleaning vessels from stubborn 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.
In water it is called hydrochloric acid ( HCl).
Physical properties of hydrochloric acid
Under ordinary conditions, hydrochloric acid is a clear, colorless liquid and has a strong unpleasant odor.
Concentrated hydrochloric acid contains 37% hydrogen chloride. Such acid "smokes" in the air. Hydrogen chloride is released from it, which, with water vapor in the air, forms a "fog" consisting of small droplets of hydrochloric acid. Hydrochloric acid is slightly heavier than water (the specific gravity of 37% hydrochloric acid is 1.19).
In school laboratories, most of the diluted hydrochloric acid is used.
Chemical properties of hydrochloric acid
Hydrochloric acid solution has a sour taste. Litmus in this solution is red in color, and phenolphthalein remains colorless.
Substances whose color changes from the action of alkalis and acids are called indicators.
Litmus, phenolphthalein - indicators for acids and alkalis. With the help of indicators, you can determine if there is an acid or alkali in the solution.
Hydrochloric acid reacts with many metals. The interaction of hydrochloric acid with sodium is especially vigorous. This can be easily verified by an experiment that can be carried out in the device.
Approximately 1/4 of its volume of concentrated hydrochloric acid is poured into a test tube, fixed in a tripod and a small piece of sodium (the size of a pea) is immersed in it. Hydrogen is released from the test tube, which can be set on fire, and small crystals of sodium chloride settle to the bottom of the test tube.
From this experience, it follows that sodium displaces hydrogen from the acid and combines with the rest of its molecule:
2Na + 2HCl \u003d 2NaCl + H 2?
Under the action of hydrochloric acid on zinc, hydrogen is released, and the substance zinc chloride ZnCl 2 remains in the solution.
Since zinc is divalent, each zinc atom replaces two hydrogen atoms in two hydrochloric acid molecules:
Zn + 2HCl \u003d ZnCl 2 + H 2?
Hydrochloric acid also acts on iron, aluminum and many other metals.
As a result of these reactions, hydrogen is released, and chloride metals remain in the solutions: ferric chloride FeCl 2, aluminum chloride AlCl 3, etc.
These chloride metals are the products of the replacement of hydrogen in hydrochloric acid with metals.
Complex substances, which can be considered as products of the replacement of hydrogen with a metal, are called salts.
Chloride metals are salts of hydrochloric acid.
Neutralization reaction (equation)
A very important chemical property of hydrochloric acid is its interaction with bases. Let us first consider its interaction with alkalis, for example, with caustic soda.
For this purpose, pour a small amount of a diluted sodium hydroxide solution into a glass cup and add a few drops of litmus solution to it.
The liquid will turn blue. Then we will pour in small portions into the same glass a solution of hydrochloric acid from a graduated tube (burette) until the color of the liquid in the glass turns purple. The violet color of the litmus shows that there is neither acid nor alkali in the solution.
This solution is called neutral. After boiling water from it, sodium chloride NaCl will remain. Based on this experience, it can be concluded that when the solutions of caustic soda and hydrochloric acid are merged, water and sodium chloride are obtained. Water molecules are formed by combining hydrogen atoms (from acid molecules) with hydroxyl groups (from alkali molecules). Sodium chloride molecules were formed from sodium atoms (from alkali molecules) and chlorine atoms - acid residues. The equation for this reaction can be written as follows:
Na | OH + H | Cl \u003d NaCl + H 2 O
Other alkalis also react with hydrochloric acid - caustic potassium, caustic calcium.
Let's get acquainted with how hydrochloric acid reacts with insoluble bases, for example, with copper oxide hydrate. To this end, put a certain amount of this base in a glass and carefully add hydrochloric acid to it until the copper oxide hydrate is completely dissolved.
After evaporation of the thus obtained blue solution, crystals of copper chloride CuCl 2 are obtained. On this basis, the following equation can be written:
And in this case, a reaction similar to the interaction of this acid with alkalis took place: hydrogen atoms from acid molecules combined with hydroxyl groups from base molecules, water molecules were formed. Copper atoms combined with chlorine atoms (residues from acid molecules) and formed salt molecules - copper chloride.
Hydrochloric acid reacts in the same way with other insoluble bases, for example, with iron oxide hydrate:
Fe (OH) 3 + 3HCl \u003d 3H 2 O + FeCl 3
The reaction of an acid with a base, resulting in salt and water, is called neutralization.
Hydrochloric acid is found in small amounts in the gastric juice of humans and animals and plays an important role in digestion.
Hydrochloric acid is used to neutralize alkalis and obtain chloride salts. It also finds application in the production of certain plastics and medicines.
Application of hydrochloric acid
Hydrochloric acid is widely used in the national economy, and you will often meet with it in the study of chemistry.
Large amounts of hydrochloric acid are consumed in pickling the steel. In everyday life, nickel-plated, zinc-plated, tin-plated (tin-plated), chrome-plated products are widely used. To cover steel products and sheet iron with a layer of protective metal from the surface, you must first remove the film of iron oxides, otherwise the metal will not stick to it. Removal of oxides is achieved by etching the product with hydrochloric or sulfuric acid. The disadvantage of etching is that the acid reacts not only with the oxide, but also with the metal. To avoid this, a small amount of inhibitor is added to the acid. Inhibitors are substances that slow down unwanted reactions. Inhibited hydrochloric acid can be stored in steel containers and transported in steel tanks.
You can also buy a hydrochloric acid solution at a pharmacy. Doctors prescribe a diluted solution to her patients with low acidity of gastric juice.
Application of hydrochloric acid
Hydrochloric acid is widely used in industry in the extraction of metals from ores, etching of metals, etc. It is also used in the manufacture of brazing fluid, in the deposition of silver and as an integral part of royal vodka.
The scale of application 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 gummed tanks and barrels, i.e. in vessels, the inner surface of which is covered with acid-resistant rubber, as well as in glass bottles and plastic containers.
Hydrochloric acid is used to obtain chlorides of zinc, manganese, iron and other metals, as well as ammonium chloride. Hydrochloric acid is used to clean the surfaces of metals, vessels, wells from carbonates, oxides and other sediments and contaminants. At the same time, special additives are used - inhibitors that 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.
First aid and treatment methods
If signs of poisoning are found, an ambulance must be called. At home, it is allowed to carry out activities aimed at improving the condition of the victim. First aid for hydrochloric acid poisoning should be carried out quickly to reduce the risk of negative consequences.
Activity:
- If the salt compound gets on the skin, the damaged area is washed with plenty of cool water. The processing time is at least half an hour.
- In case of intoxication with vapors, the victim is provided with fresh air, windows are opened, and tight clothes are unbuttoned.
- It is recommended to monitor the patient's condition, in the absence of signs of life, resuscitation actions are performed.
- The victim of the vapors is allowed to give warm tea and water to drink. It is recommended to rinse the nasal cavity and mouth with cool water.
- In case of an overdose resulting from ingestion of acid, an ice pack is placed on the stomach to exclude or reduce possible bleeding.
- The use of any medicines is not allowed. It is allowed to give the patient a glass of water (mineral alkaline is possible). Drinking liquid is required in small sips.
- It is not allowed to wash out the stomach, try to induce vomiting at home. Such first aid can lead to the development of throat burns, bleeding.
Treatment is carried out in a medical facility under the supervision of specialists.
Therapy:
- Cleansing the stomach with a probe,
- Using droppers with medicinal solutions,
- Prescription of drugs that relieve painful sensations,
- The use of medicines aimed at restoring the functioning of organs and systems,
- If necessary, oxygen inhalation and artificial lung ventilation,
- Resuscitation therapy in the absence of signs of life,
- Selection of vitamins and special food.
Treatment is carried out in intensive care and then in a hospital. The duration depends on the patient's condition and the degree of poisoning.
Burns and poisoning
As effective as this remedy is, it is dangerous. Hydrochloric acid, depending on the concentration, can provoke four degrees of chemical burns:
- There is only redness and pain.
- Blisters with a clear liquid and edema appear.
- Necrosis of the upper layers of the skin is formed. Bubbles fill with blood or cloudy contents.
- The lesion reaches the tendons and muscles.
If the substance somehow gets into the eyes, rinse them with water and then with a soda solution. But in any case, the first thing to do is call an ambulance.
Acid ingestion is fraught with sharp pains in the chest and abdomen, laryngeal edema, vomit blood masses. As a result, severe liver and kidney pathologies.
And the first signs of vapor poisoning include dry, frequent cough, choking, tooth damage, burning sensation in the mucous membranes and abdominal pain. First-aid measures include washing and rinsing the mouth with water and access to fresh air. Only a toxicologist can provide real help.
Chemical spectrum properties
The acid interacts with many metals and salts. It is considered quite strong and is on a par with chamois. The main reaction manifests itself on all groups of metals located to the left of hydrogen (magnesium, iron, zinc - electrical potentials).
A diluted hydrogen chloride solution reacts with salts, but only with those formed by less strong acids. The well-known sodium and calcium carbonate, after interacting with it, decomposes into water and carbon monoxide.
Nitric acid
- qualitative reaction to saline solution. To obtain it, it is necessary to add silver nitrate to this reagent, as a result, a white precipitate will form, from which a nitrogen substance is obtained
Many interesting experiments have been carried out using this mixture of water and hydrogen. For example, dilute it with ammonia. As a result, you get white smoke, thick, having the consistency of small crystals. Methylamine, aniline, manganese dioxide, potassium carbonate are reagents that are also susceptible to acid.
How and for what they are used
Perhaps this is rightfully one of the important substances that is found and necessary in almost all areas of human life.
Localization of the field of application:
- Metallurgy. Cleaning surfaces from oxidized areas, dissolving rust, processing before soldering, tinning. Hydrochloric acid helps to extract small particles of metals from ores. Zirconium and titanium are obtained using the method of converting oxides to chlorides.
- Food technology industry. The low concentration solution is used as a food additive. Gelatin, fructose for diabetics contain a pure emulsifier. Regular soda also has a high content of this substance. You will see it on the packaging of goods under the name E507.
- The field of medicine. With an insufficient indicator of the acidic environment in the stomach and problems with the intestines. Low Ph levels lead to cancer. Even with proper nutrition, vitamins in abundance, the danger does not disappear, it is necessary to carry out tests to obtain juice from the gastric tract, because with an insufficiently acidic environment, nutrients are practically not absorbed, digestion is disturbed.
- Salt solution is used as an inhibitor - protection against dirt and infections, antiseptic effect. For the manufacture of adhesive mixtures, ceramic products. It is washed by heat exchangers.
- The procedure for purifying drinking water is also not complete without the participation of chlorine.
- Manufacturing of rubber, bleaching of fabric bases.
- You can take care of your lenses with this solution.
- Home rinsing
- The substance perfectly conducts electric current.
How does the poisoning happen
Hydrochloric acid - liquid substance colorless, but with a characteristic pungent odor. One of the strongest acids, it can dissolve some metals. Easily converts to gas.
Hydrogen chloride is used in the textile industry, tanning, metallurgy of precious metals, in the production of adhesives and acids.
The substance is present in the stomach at a minimum concentration. The acid helps to normalize the digestive process, protects the body from harmful bacteria and microorganisms.
At a concentration exceeding 24%, hydrochloric acid is capable of causing irreversible harm to the human body. Vapors generated on contact with air irritate the visual and respiratory system.
There are several factors that can provoke the development of poisoning.
Intoxication by vapors is possible when working in rooms with poor ventilation,
Ingestion through negligence, more often occurs in children,
Contact with hydrochloric acid on the epidermis, mucous membrane if the rules for using the reagent are not followed.
Poisoning with a substance at home in adults occurs as a result of the use of the skin, eyes, and respiratory system without protective equipment. Intoxication can occur with inaccurate transfusion of acid from one container to another.
Pharmacodynamics and pharmacokinetics
What is gastric acidity? This is a characteristic of the concentration of Hydrochloric Acid in the stomach. Acidity is expressed in pH
... Normally, acid should be produced in the composition of gastric juice and take an active part in digestion processes. Hydrochloric acid formula: HCl
... It is produced by parietal cells located in the fundic glands, with the participation H + / K + -ATPase
... These cells line the fundus and body of the stomach. The acidity of the gastric juice itself is variable and depends on the number of parietal cells and the intensity of the processes of neutralization of the substance by the alkaline components of the gastric juice. The concentration of the produced to-you is stable and equal to 160 mmol / l. A healthy person should normally produce no more than 7 and no less than 5 mmol of a substance per hour.
With insufficient or excessive production of Hydrochloric Acid, diseases of the digestive tract occur, the ability to assimilate some trace elements, for example, iron, deteriorates. The product stimulates the secretion of gastric juice, reduces pH
... Activates pepsinogen
, converts it into an active enzyme pepsin
... The substance has a beneficial effect on the acid reflex of the stomach, slows down the passage of not fully digested food into the intestines. The processes of fermentation of the contents of the digestive tract slow down, pain and belching disappear, iron is better absorbed.
After oral administration, the agent is partially metabolized by saliva and gastric mucus contained in the duodenum. The unbound substance penetrates into the duodenum, where it is completely neutralized by its alkaline contents.
Other household uses of acid
With an acidic composition, you can easily clean plumbing from faience from limescale and rust, remove urinary tartar and other contaminants. For a greater effect, an inhibitor (for example, urotropine) is added to the agent, which slows down the chemical reaction.
The procedure is carried out as follows: the acid is diluted with water until a 5% concentration is reached and an inhibitor is added at the rate of 0.5 g per 1 liter of liquid. The resulting composition is treated with the surface and left for 30-40 minutes (depending on the degree of contamination), then washed with water.
A mild acidic solution is also used to remove berry stains, ink or rust from fabrics. To do this, the material is soaked in the composition for a while, after which it is thoroughly rinsed and washed as usual.
Kettle descaling
For this purpose, a 3-5% solution of hydrochloric acid is used, which is poured into a kettle and heated to 60-80 °
C for 1-2 hours or until the scale deposits disintegrate. After that, the scale becomes loose and can be easily removed with a wooden spatula.
The effectiveness of the method is due to the fact that the reagent reacts with magnesium and calcium carbonates and converts them into soluble salts. The emitted carbon dioxide destroys the scale layer and makes it friable. After removing the salt deposits, the dishes are thoroughly washed with clean water.
An important point!
This method is not suitable for descaling enamelled or aluminum teapots with chips and cracks: this will corrode the metal and severely damage it.
Getting the substance
Now we can talk about what is being done to form hydrochloric acid.
First, by burning hydrogen in chlorine, the main component is obtained - gaseous hydrogen chloride. 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 offgas. These are chemical waste gases. They are formed in a wide variety of processes. For example, in the chlorination of hydrocarbons. The hydrogen chloride contained in them is called offgas. And the acid thus obtained, respectively.
It should be noted that in last years the share of off-gas substances in the total volume of its production is increasing. And the acid formed as a result of combustion of hydrogen in chlorine is displaced. However, in fairness, it should be noted that it contains fewer impurities.
Production use
It is widely used in the metallurgical, food and medical industries.
- Metallurgy. Application for soldering, tinning and metal stripping.
- Food industry. Application in the production of food acidity regulators, for example, E507.
- Electrotype. Used for etching.
- Medicine. It is used in the production of artificial gastric juice.
Part of synthetic dyes. Used in the manufacture of cleaning and detergents. But in liquids intended for domestic use, the concentration of sulfuric acid is negligible.
How hydrochloric acid is obtained in the laboratory
The production of the substance is large-scale, the sale is free. Under laboratory conditions, a solution is obtained by the action of high concentration sulfuric acid on ordinary kitchen salt (sodium chloride).
There are 2 methods for dissolving hydrogen chloride in water:
- Hydrogen is combusted in chlorine (synthetic).
- Passing (abgas). Its essence is in organic chlorination, dehydrochlorination.
The substance lends itself well to synthesis during the pyrolysis of waste from organochlorine. This happens as a result of the decomposition of hydrocarbons with a complete oxygen deficiency. You can also use metal chlorides, which are raw materials of inorganic substances. If there is no concentrated sulfuric acid (electrolyte), take a diluted one.
As for the extraction of the reagent in natural conditions, then most often this chemical mixture can be found in the waters of volcanic waste. Hydrogen chloride is a component of the minerals sylvin (potassium chloride, it looks like bones for games), bischofite. These are all methods of obtaining the substance in the industry.
In the human body, this enzyme is found in the stomach. The solution can be either acid or base. One of the common methods of extraction is called sulfate.
Chemical properties
Hydrochloric acid, hydrogen chloride or hydrochloric acid - solution Hcl
in water. According to Wikipedia, the substance belongs to the group of inorganic strong monobasic to-t. Full name of the compound in Latin: Hydrochloricum acid.
Formula of Hydrochloric Acid in Chemistry: HCl
... In a molecule, hydrogen atoms combine with halogen atoms - Cl
... If we consider the electronic configuration of these molecules, it can be noted that compounds are involved in the formation of molecular orbitals 1s
-orbitals of hydrogen and both 3s
and 3p
-orbitals of an atom Cl
... In the chemical formula of Hydrochloric Acid 1s-
, 3s-
and 3p
-atomic orbitals overlap and form 1, 2, 3 -orbitals. Wherein 3s
-orbital is not binding. There is a shift of the electron density toward the atom Cl
and the polarity of the molecule decreases, but the binding energy of molecular orbitals increases (if we consider it along with other hydrogen halides
).
Physical properties of hydrogen chloride. It is a clear, colorless liquid that has the ability to smoke when in contact with air. The molar mass of a chemical compound \u003d 36.6 grams per mole. Under standard conditions, at an air temperature of 20 degrees Celsius, the maximum concentration of the substance is 38% by weight. The density of concentrated hydrochloric acid in this kind of solution is 1.19 g / cm³. In general, physical properties and characteristics such as density, molarity, viscosity, heat capacity, boiling point and ph
, strongly depend on the concentration of the solution. These values \u200b\u200bare discussed in more detail in the table of densities. For example, the density of Hydrochloric Acid is 10% \u003d 1.048 kg per liter. When solidified, the substance forms crystal hydrates
different compositions.
Chemical properties of hydrochloric acid. What does Hydrochloric acid react with? The substance interacts with metals, which are in the series of electrochemical potentials in front of hydrogen (iron, magnesium, zinc and others). In this case, salts are formed and gaseous H
... Lead, copper, gold, silver and other metals to the right of hydrogen do not react with hydrochloric acid. The substance reacts with metal oxides to form water and soluble salt. Sodium hydroxide under the action of to - you forms water. The neutralization reaction is characteristic of this compound.
Diluted Hydrochloric Acid reacts with metal salts, which are formed by weaker ones. For instance, propionic acid
weaker than saline. The substance does not interact with stronger acids. and sodium carbonate
will form after reaction with HCl
chloride, carbon monoxide and water.
A chemical compound is characterized by reactions with strong oxidants, with manganese dioxide
, potassium permanganate
: 2KMnO4 + 16HCl \u003d 5Cl2 + 2MnCl2 + 2KCl + 8H2O
... The substance reacts with ammonia
, a thick white smoke is formed, which consists of very small crystals of ammonium chloride. Mineral pyrolusite with hydrochloric acid also reacts, as it contains manganese dioxide
: MnO2 + 4HCl \u003d Cl2 + MnO2 + 2H2O
(oxidation reaction).
There is a qualitative reaction to hydrochloric acid and its salts. When a substance interacts with silver nitrate
white precipitate falls silver chloride
and formed nitric acid
... Interaction reaction equation methylamine
with hydrogen chloride is as follows: HCl + CH3NH2 \u003d (CH3NH3) Cl
.
The substance reacts with a weak base aniline
... After dissolving the aniline in water, hydrochloric acid is added to the mixture. As a result, the base dissolves and forms aniline hydrochloric acid
(phenylammonium chloride
): (C6H5NH3) Cl
... Aluminum carbide react with hydrochloric acid: Al4C3 + 12HCL \u003d 3CH4 + 4AlCl3
... Reaction equation potassium carbonate
with that looks like this: K2CO3 + 2HCl \u003d 2KCl + H2O + CO2.
Application
in metallurgy for the extraction of ores, removal of rust, scale, dirt and oxides, brazing and tinning;
in the manufacture of synthetic rubbers and resins;
in electroplating;
as an acidity regulator in the food industry;
for the production of metal chlorides;
for chlorine production;
in medicine for the treatment of insufficient acidity of gastric juice;
as a cleaning and disinfecting agent.
- (HCl), an aqueous solution of hydrogen chloride, a colorless gas with a pungent odor. Obtained by the action of sulfuric acid on table 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, antifreeze additive. It is a colorless liquid with a pungent odor, without suspended particles. ... ... Encyclopedia of terms, definitions and explanations building materials
- (hydrochloric acid) solution of hydrogen chloride in water; strong acid. Colorless liquid fuming in air (technical hydrochloric acid is yellowish due to impurities of Fe, Cl2, etc.). Maximum concentration (at 20 .C) 38% by weight, ... ... Big Encyclopedic Dictionary
- (Acidum muriaticum, Acid, hydrochloricum), a solution of hydrogen chloride (HC1) in water. In nature, it is found in the water of certain sources of volcanic origin, and is also found in gastric juice (up to 0.5%). Hydrogen chloride can be obtained ... Large medical encyclopedia
- (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 weight, the density of such a solution is 1.19 g / cm3. Used in ... ... Russian encyclopedia on labor protection
- (hydrochloric acid) HCl aqueous solution of hydrogen chloride, strong monobasic acid, volatile, with a pungent odor; iron and chlorine impurities paint it yellowish. Concentrated sulfuric acid that goes on sale contains 37% ... ... Big Polytechnic Encyclopedia
hydrochloric acid
- noun, number of synonyms: 1 acid (171) ASIS Synonym Dictionary. V.N. Trishin. 2013 ... Dictionary of synonyms
Modern encyclopedia
Hydrochloric acid
- HYDRAULIC ACID, an aqueous solution of hydrogen chloride HCl; liquid fuming in the air with a pungent odor. Hydrochloric acid is used to obtain various chlorides, etching metals, processing ores, in the production of chlorine, soda, rubbers, etc. ... ... Illustrated encyclopedic dictionary
hydrochloric acid
- (hydrochloric acid), a solution of hydrogen chloride in water; strong acid. 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
Why is intoxication dangerous?
Hydrochloric acid is a particular hazard to the human body. In case of poisoning with a similar substance, serious complications and functional disorders of the body may develop.
Complications:
- Liver dysfunction, as a result of toxic hepatitis,
- Bleeding in the stomach due to destroyed organ walls,
- Shock from pain when acid hits a large area,
- In case of eye contact, visual impairment,
- Serious kidney failure
- Respiratory distress, choking, lack of air,
- The development of a coma.
Similar consequences develop gradually depending on the degree of poisoning.
Output
Subject to precautions and safety rules, hydrochloric acid will become an irreplaceable assistant in everyday life. And you can buy it at the most affordable prices in our company
Like acids. The educational program provides for the memorization by students of the names and formulas of six representatives of this group. And, looking through the table provided by the textbook, you notice in the list of acids the one that stands first and interested you in the first place - hydrochloric acid. Alas, in the classroom at school, neither property nor any other information about it is studied. Therefore, those eager to gain knowledge outside the school curriculum are looking for additional information in all sorts of sources. But often, many do not find the information they need. And therefore, the topic of today's article is devoted to this particular acid.
Definition
Hydrochloric acid is a strong monobasic acid. In some sources, it can be called chlorine and hydrochloric, as well as hydrogen chloride.
Physical properties
It is a colorless and caustic liquid that smokes in the air (photo on the right). However, technical acid, due to the presence of iron, chlorine and other additives, has a yellowish color. Its highest concentration at a temperature of 20 ° C is 38%. The density of hydrochloric acid with such parameters is 1.19 g / cm 3. But this compound in varying degrees of saturation has completely different data. With a decrease in concentration, the numerical value of molarity, viscosity and melting point decreases, but the specific heat and boiling point increase. Solidification of hydrochloric acid of any concentration gives various crystalline hydrates.
Chemical properties
All metals that stand before hydrogen in the electrochemical range of their voltage can interact with this compound, forming salts and releasing hydrogen gas. If they are replaced with metal oxides, then the reaction products are soluble salt and water. The same effect will be observed when hydrochloric acid interacts with hydroxides. If you add to it any metal salt (for example, sodium carbonate), the residue of which was taken from a weaker acid (carbonic), then the chloride of this metal (sodium), water and gas corresponding to the acid residue (in this case, carbonic acid) are formed ...