Lesson objectives: students should know the structure, physical and chemical properties of H 2 SO 4; to be able, on the basis of knowledge about the rate of chemical reactions and chemical equilibrium, to justify the choice of the conditions for the course of reactions that underlie the production of sulfuric acid; determine in practice sulfate and sulfide ions.

Basic concepts: sulfurous anhydride, sulfuric anhydride, complex use of raw materials.

During the classes

I. Organizational moment; homework check

II. New material

1. Electronic and structural formulas. Since sulfur is in the 3rd period of the periodic system, the octet rule is not followed and the sulfur atom can acquire up to twelve electrons.

(The six electrons of sulfur are indicated by an asterisk.)

2. Receiving. Sulfuric acid is formed by the interaction of sulfur (VI) oxide with water (SO 3 + H 2 O H 2 SO 4). A description of the production of sulfuric acid is given in § 16 (pp. 37 - 42).

3. Physical properties. Sulfuric acid is a colorless, heavy (= 1.84 g / cm 3), non-volatile liquid. When it dissolves in water, a very strong heating occurs. Remember not to pour water into concentrated sulfuric acid (fig. 2)! Concentrated sulfuric acid absorbs water vapor from the air. This can be seen if an open vessel with concentrated sulfuric acid is balanced on a balance: after a while, the cup with the vessel will lower.

Rice. 2.

4. Chemical properties. Diluted sulfuric acid has general properties characteristic of acids and specific (Table 7).

Table 7

Application. Sulfuric acid is widely used (Fig. 3), it is the main product of the chemical industry.

Rice. 3. The use of sulfuric acid: 1 - obtaining dyes; 2 - mineral fertilizers; 3 - refining petroleum products; 4 - electrolytic production of copper; 5 - electrolyte in batteries; 6 - obtaining explosives; 7 - dyes; 8 - artificial silk; 9 - glucose; 10 - salts; 11 - acids.

Sulfuric acid forms two series of salts - medium and acidic:

Na 2 SO 4 NaHSO 4

sodium sulfate sodium hydrogen sulfate

(medium salt) (acidic salt)

Sulfuric acid salts are widely used, for example, Na 2 SO 4 10H 2 O - sodium sulfate crystalline hydrate (Glauber's salt) is used in the production of soda, glass, in medicine and veterinary medicine. CaSO 4 2H 2 O - calcium sulfate crystalline hydrate (natural gypsum) - is used to obtain semi-aqueous gypsum, which is necessary in construction, and in medicine - for applying plaster casts. CuSO 4 5H 2 O - crystalline hydrate of copper (II) sulfate (copper sulfate) - is used in the fight against plant pests.

III. Securing new material

1. In winter, a vessel with concentrated sulfuric acid is sometimes placed between the window frames. For what purpose is this done, why the vessel cannot be filled up to the top with acid?

2. Concentrated sulfuric acid, when heated, reacts with mercury and silver, in the same way as it reacts with copper. Write down the equations for these reactions and indicate the oxidizing agent and the reducing agent.

3. How to recognize sulfides? Where are they used?

4. Make the reaction equations that are practically feasible using the following schemes:

Hg + H 2 SO 4 (conc)

MgCl 2 + H 2 SO 4 (conc.)

Na 2 SO 3 + H 2 SO 4

Al (OH) 3 + H 2 SO 4

When drawing up the equations of reactions, indicate the conditions for their implementation. Where applicable, write the equations in ionic and abbreviated ionic form.

5. Name the oxidizing agent in the reactions: a) dilute sulfuric acid with metals; b) concentrated sulfuric acid with metals.

6. What do you know about sulfurous acid?

7. Why is concentrated sulfuric acid a strong oxidizing agent? What are the special properties of concentrated sulfuric acid?

8. How does concentrated sulfuric acid interact with metals?

9. Where are sulfuric acid and its salts used?

1. What volume of oxygen is required for combustion: a) 3.4 kg of hydrogen sulfide; b) 6500 m 3 of hydrogen sulfide?

2. What is the mass of a solution containing 0.2 mass fractions of sulfuric acid, which is consumed for the reaction with 4.5 g of aluminum?

Laboratory experiments

Vi. Recognition of sulfate ions in solution. Pour 1-2 ml of sodium sulfate solution into one tube, the same amount of zinc sulfate into the other, and a diluted sulfuric acid solution into the third. Place a zinc pellet in each tube, and then add a few drops of barium chloride or barium nitrate solution.

Tasks. 1. How can you distinguish sulfuric acid from its salts? 2. How to distinguish sulfates from other salts? Write the equations for the reactions you did in molecular, ionic, and abbreviated ionic form.

IV. Homework

New topic: Sulfuric acid -H 2 SO 4

1. Electronic and structural formulas of sulfuric acid

* S - sulfur is in an excited state 1S 2 2S 2 2P 6 3S 1 3P 3 3d 2

The electronic formula of the sulfuric acid molecule:

Sulfuric acid molecule structural formula:

1 H - -2 O -2 O

1 H - -2 O -2 O

2.Receiving:

The chemical processes for the production of sulfuric acid can be represented as the following diagram:

S + O 2 + O 2 + H 2 O

FeS 2 SO 2 SO 3 H 2 SO 4

Sulfuric acid is obtained in three stages:

1st stage. Sulfur, iron pyrite or hydrogen sulfide are used as raw materials.

4 FeS 2 + 11 O 2 = 2Fe 2 O 3 + 8SO 2

2 stage. Oxidation of SO 2 to SO 3 with oxygen using a V 2 O 5 catalyst

2SO 2 + O 2 = 2SO 3 + Q

3stage. For the conversion of SO 3 into sulfuric acids, not water is used. there is a strong heating, and a concentrated solution of sulfuric acid.

SO 3 + H 2 O H 2 SO 4

The result is an oleum solutionSO 3 in sulfuric acid.

Apparatus circuit diagram(see tutorial page 105)

3. Physical properties.

a) liquid b) colorless c) heavy (vitriol oil) d) non-volatile

d) when dissolved in water, strong heating occurs ( therefore, sulfuric acid must certainly be poured intowater,anot the other way around!)

4. Chemical properties of sulfuric acid.

5.Application: Sulfuric acid is one of the most important products used in various industries. Its main consumers are the production of mineral fertilizers, metallurgy, and refining of petroleum products. Sulfuric acid is used in the production of other acids, detergents, explosives, medicines, paints, as electrolytes for lead-acid batteries. (Tutorial page 103).

6.Sulfuric acid salts

Sulfuric acid dissociates in steps

H 2 SO 4 H + + HSO 4 -

HSO 4 - H + + SO 4 2-

therefore, it forms two types of salt - sulfates and hydrosulfates

For example: Na 2 SO 4 - sodium sulfate (medium salt)

Na HSO 4 - sodium hydrogen sulfate (acidic salt)

The most widely used are:

Na 2 SO 4 * 10H 2 O - Glauber's salt (used in the production of soda, glass, in medicine and

veterinary medicine.

СaSO 4 * 2H 2 O - gypsum

СuSO 4 * 5H 2 O - copper sulfate (used in agriculture).

Laboratory experience

Chemical properties of sulfuric acid.

Equipment: Test tubes.

Reagents: sulfuric acid, methyl orange, zinc, magnesium oxide, sodium hydroxide and phenolphthalein, sodium carbonate, barium chloride.

b) Fill in the observation table

Sulfuric acid (H2SO4) is one of the most corrosive acids and dangerous reagents known to man, especially in concentrated form. Chemically pure sulfuric acid is a heavy toxic liquid of oily consistency, odorless and colorless. It is obtained by the method of oxidation of sulfur dioxide (SO2) by the contact method.

At a temperature of + 10.5 ° C, sulfuric acid turns into a solidified glassy crystalline mass, greedily, like a sponge, absorbing moisture from the environment. In industry and chemistry, sulfuric acid is one of the main chemical compounds and occupies a leading position in terms of production in tons. That is why sulfuric acid is called "the blood of chemistry." With the help of sulfuric acid, fertilizers, medicines, other acids, large, fertilizers and much more are obtained.

Basic physical and chemical properties of sulfuric acid

1. Sulfuric acid in its pure form (formula H2SO4), at a concentration of 100%, is a colorless thick liquid. The most important property of H2SO4 is its high hygroscopicity - it is the ability to remove water from the air. This process is accompanied by a large-scale release of heat.
2. H2SO4 is a strong acid.
3. Sulfuric acid is called monohydrate - it contains 1 mol of H2O (water) for 1 mol of SO3. Because of its impressive hygroscopic properties, it is used to extract moisture from gases.
4. The boiling point is 330 ° C. In this case, the acid decomposes into SO3 and water. Density - 1.84. Melting point - 10.3 ° C /.
5. Concentrated sulfuric acid is a powerful oxidizing agent. To start the redox reaction, the acid needs to be heated. The result of the reaction is SO2. S + 2H2SO4 = 3SO2 + 2H2O
6. Depending on the concentration, sulfuric acid reacts differently with metals. In a diluted state, sulfuric acid is capable of oxidizing all metals that are in the range of voltages to hydrogen. The exception is as the most resistant to oxidation. Diluted sulfuric acid reacts with salts, bases, amphoteric and basic oxides. Concentrated sulfuric acid is capable of oxidizing all metals in a series of voltages, including silver.
7. Sulfuric acid forms two types of salts: acidic (these are hydrosulfates) and medium (sulfates)
8. H2SO4 reacts actively with organic substances and non-metals, some of which it can turn into coal.
9. Sulfuric anhydrite dissolves perfectly in H2SO4, and oleum is formed - a solution of SO3 in sulfuric acid. Outwardly, it looks like this: fuming sulfuric acid, releasing sulfuric anhydrite.
10. Sulfuric acid in aqueous solutions is a strong dibasic, and when it is added to water, a huge amount of heat is released. When dilute solutions of H2SO4 are prepared from concentrated solutions, it is necessary to add a heavier acid to water in a small trickle, and not vice versa. This is done to avoid water boiling and acid splashing.

Concentrated and diluted sulfuric acids

Concentrated sulfuric acid solutions include solutions of 40% or more capable of dissolving silver or palladium.

Dilute sulfuric acid includes solutions whose concentration is less than 40%. These are not such active solutions, but they are capable of reacting with brass and copper.

Sulfuric acid production

The production of sulfuric acid on an industrial scale was launched in the 15th century, but at that time it was called "vitriol oil". If earlier humanity consumed only a few tens of liters of sulfuric acid, then in the modern world the calculation goes to millions of tons per year.

Sulfuric acid is produced industrially, and there are three of them:

1. Contact method.
2. Nitrous way
3. Other methods

Let's talk in detail about each of them.

Contact production method

The contact method of production is the most common, and it performs the following tasks:

• The result is a product that meets the needs of the maximum number of consumers.
• During production, harm to the environment is reduced.

In the contact method, the following substances are used as raw materials:

• pyrite (sulfur pyrite);
• sulfur;
• vanadium oxide (this substance acts as a catalyst);
• hydrogen sulfide;
• sulfides of various metals.

Before starting the production process, the raw materials are pre-prepared. To begin with, pyrite is crushed in special crushing plants, which allows, due to the increase in the contact area of ​​active substances, to accelerate the reaction. Pyrite is purified: it is dipped into large containers of water, during which waste rock and all kinds of impurities float to the surface. At the end of the process, they are removed.

The production part is divided into several stages:

1. After crushing, the pyrite is purified and sent to the furnace, where it is fired at temperatures up to 800 ° C. According to the counterflow principle, air is supplied into the chamber from below, and this ensures that the pyrite is in a suspended state. Today, this process takes a few seconds, but earlier it took several hours to bake. During the roasting process, waste in the form of iron oxide appears, which is removed and then transferred to the metallurgical industry. Firing produces water vapor, O2 and SO2 gases. When the purification from water vapor and the smallest impurities is completed, pure sulfur oxide and oxygen are obtained.
2. In the second stage, an exothermic reaction takes place under pressure using a vanadium catalyst. The reaction starts when the temperature reaches 420 ° C, but it can be increased to 550 ° C in order to increase the efficiency. During the reaction, catalytic oxidation takes place and SO2 becomes SO3.
3. The essence of the third stage of production is as follows: absorption of SO3 in the absorption tower, during which oleum H2SO4 is formed. In this form, H2SO4 is poured into special containers (it does not react with steel) and is ready to meet with the end consumer.

In the course of production, as we said above, a lot of thermal energy is generated, which is used for heating purposes. Many sulfuric acid plants install steam turbines that use the emitted steam to generate additional electricity.

Nitrous method for producing sulfuric acid

Despite the advantages of the contact method of production, in which more concentrated and pure sulfuric acid and oleum are obtained, a lot of H2SO4 is obtained by the nitrous method. In particular, at superphosphate plants.

For the production of H2SO4, sulfur dioxide acts as the starting material, both in the contact and in the nitrous method. It is obtained specifically for these purposes by burning sulfur or by burning sulphurous metals.

The processing of sulfur dioxide into sulfurous acid consists in the oxidation of sulfur dioxide and the addition of water. The formula looks like this:
SO2 + 1 | 2 O2 + H2O = H2SO4

But sulfur dioxide does not directly react with oxygen, therefore, with the nitrous method, sulfur dioxide is oxidized using nitrogen oxides. Higher nitrogen oxides (we are talking about nitrogen dioxide NO2, nitrogen trioxide NO3) in this process are reduced to nitrogen oxide NO, which is subsequently again oxidized by oxygen to higher oxides.

The production of sulfuric acid by the nitrous method is technically formalized in two ways:

• Chamber.
• Tower.

The nitrous method has a number of advantages and disadvantages.

Disadvantages of the nitrous method:

• It turns out 75% sulfuric acid.
• The product quality is poor.
• Incomplete return of nitrogen oxides (addition of HNO3). Their emissions are harmful.
• The acid contains iron, nitrogen oxides and other impurities.

Advantages of the nitrous method:

• The cost of the process is lower.
• 100% recyclable SO2.
• Simplicity of hardware design.

Major Russian plants for the production of sulfuric acid

The annual production of H2SO4 in our country is calculated in six figures - it is about 10 million tons. The leading producers of sulfuric acid in Russia are companies, which, in addition, are its main consumers. We are talking about companies whose field of activity is the production of mineral fertilizers. For example, "Balakovo Mineral Fertilizers", "Ammophos".

The largest titanium dioxide producer in Eastern Europe, Crimean Titanium, operates in Armyansk in Crimea. In addition, the plant is engaged in the production of sulfuric acid, mineral fertilizers, ferrous sulfate, etc.

Sulfuric acid of various types is produced by many factories. For example, battery sulfuric acid is produced by: Karabashmed, FKP Biysk Oleum Plant, Svyatogor, Slavia, Severkhimprom, etc.

Oleum is produced by UCC Shchekinoazot, FKP Biysk Oleum Plant, Ural Mining and Metallurgical Company, PO Kirishinefteorgsintez, etc.

Sulfuric acid of high purity is produced by OHK Shchekinoazot, Component-Reagent.

Spent sulfuric acid can be bought at the factories ZSS, HaloPolymer Kirovo-Chepetsk.

Producers of technical sulfuric acid are Promsintez, Khiprom, Svyatogor, Apatit, Karabashmed, Slavia, Lukoil-Permnefteorgsintez, Chelyabinsk Zinc Plant, Electrozinc, etc.

Due to the fact that pyrite is the main raw material in the production of H2SO4, and this is a waste of the enrichment enterprises, its suppliers are the Norilsk and Talnakh enrichment factories.

The world leaders in the production of H2SO4 are occupied by the USA and China, which account for 30 million tons and 60 million tons, respectively.

Scope of application of sulfuric acid

The world annually consumes about 200 million tons of H2SO4, from which a wide range of products are produced. Sulfuric acid rightfully holds the palm among other acids in terms of industrial use.

As you already know, sulfuric acid is one of the most important products of the chemical industry, so the field of application of sulfuric acid is quite wide. The main directions of using H2SO4 are as follows:

• Sulfuric acid is used in colossal volumes for the production of mineral fertilizers, and this takes about 40% of the total tonnage. For this reason, H2SO4 plants are built next to fertilizer plants. These are ammonium sulfate, superphosphate, etc. In their production, sulfuric acid is taken in pure form (100% concentration). To produce a ton of ammophos or superphosphate, you need 600 liters of H2SO4. It is these fertilizers that are used in most cases in agriculture.
• H2SO4 is used for the production of explosives.
• Refining of petroleum products. To obtain kerosene, gasoline, mineral oils, hydrocarbon purification is required, which occurs with the use of sulfuric acid. In the process of oil refining for the purification of hydrocarbons, this industry "takes" as much as 30% of the world tonnage of H2SO4. In addition, the octane number of the fuel is increased with sulfuric acid and wells are treated during oil production.
• In the metallurgical industry. Sulfuric acid in metallurgy is used for descaling and rusting wire, sheet metal, as well as for the recovery of aluminum in the production of non-ferrous metals. Before coating metal surfaces with copper, chromium or nickel, the surface is etched with sulfuric acid.
• In the production of pharmaceuticals.
• In the production of paints.
• In the chemical industry. H2SO4 is used in the production of detergents, ethyl detergent, insecticides, etc., and without it, these processes are impossible.
• For the production of other known acids, organic and inorganic compounds used for industrial purposes.

Sulfuric acid salts and their use

The most important sulfuric acid salts:

• Glauber's salt Na2SO4 · 10H2O (crystalline sodium sulfate). The scope of its application is quite capacious: the production of glass, soda, in veterinary medicine and medicine.
• Barium sulfate BaSO4 is used in the production of rubber, paper, white mineral paint. In addition, it is indispensable in medicine for gastric fluoroscopy. It is used to make "barium porridge" for this procedure.
• Calcium sulfate CaSO4. In nature, it can be found in the form of gypsum CaSO4 2H2O and anhydrite CaSO4. Gypsum CaSO4 · 2H2O and calcium sulfate are used in medicine and construction. With gypsum, when heated to a temperature of 150 - 170 ° C, partial dehydration occurs, as a result of which burnt gypsum, known to us as alabaster, is obtained. Kneading alabaster with water to the consistency of a batter, the mass quickly hardens and turns into a kind of stone. It is this property of alabaster that is actively used in construction work: casts and casting molds are made from it. In plastering works, alabaster is indispensable as a binding material. Patients of trauma departments are given special fixing solid bandages - they are made on the basis of alabaster.
• Iron vitriol FeSO4 · 7H2O is used for the preparation of ink, impregnation of wood, as well as in agricultural activities for the destruction of pests.
• Alum KCr (SO4) 2 · 12H2O, KAl (SO4) 2 · 12H2O, etc. is used in the production of paints and the tanning industry (leather tanning).
• Copper sulfate CuSO4 · 5H2O many of you know firsthand. It is an active assistant in agriculture in the fight against plant diseases and pests - an aqueous solution of CuSO4 · 5H2O is used to pickle grain and spray the plants. It is also used for the preparation of some mineral paints. And in everyday life, it is used to remove mold from the walls.
• Aluminum sulphate - it is used in the pulp and paper industry.

Diluted sulfuric acid is used as an electrolyte in lead-acid batteries. In addition, it is used for the production of detergents and fertilizers. But in most cases it comes in the form of oleum - it is a solution of SO3 in H2SO4 (you can also find other oleum formulas).

Amazing fact! Oleum is more chemically active than concentrated sulfuric acid, but despite this, it does not react with steel! It is for this reason that it is easier to transport it than the sulfuric acid itself.

The field of use of the "queen of acids" is truly large, and it is difficult to tell about all the ways it is used in industry. It is also used as an emulsifier in the food industry, for water purification, in the synthesis of explosives, and for many other purposes.

The history of the appearance of sulfuric acid

Who among us has never heard of copper sulfate? So, it was studied in antiquity, and in some works of the beginning of the new era, scientists discussed the origin of vitriol and their properties. The vitriol was studied by the Greek physician Dioscorides, the Roman researcher of nature Pliny the Elder, and in their writings they wrote about the experiments being carried out. For medical purposes, various vitriol substances were used by the ancient healer Ibn Sina. How vitriol was used in metallurgy was mentioned in the works of the alchemists of ancient Greece Zosima of Panopolis.

The first method for producing sulfuric acid is the process of heating potassium alum, and there is information about this in the alchemical literature of the 13th century. At that time, the composition of alum and the essence of the process were not known to alchemists, but already in the 15th century, the chemical synthesis of sulfuric acid began to be dealt with purposefully. The process was as follows: alchemists treated a mixture of sulfur and antimony (III) sulfide Sb2S3 while heating with nitric acid.

In medieval times in Europe, sulfuric acid was called "vitriol oil", but then the name changed to vitriol acid.

In the 17th century, Johann Glauber obtained sulfuric acid as a result of the combustion of potassium nitrate and native sulfur in the presence of water vapor. As a result of the oxidation of sulfur with nitrate, sulfur oxide was obtained, which reacted with water vapor, and as a result, a liquid of oily consistency was obtained. It was vitriol oil, and this name for sulfuric acid still exists today.

London pharmacist Ward Joshua used this reaction for the industrial production of sulfuric acid in the thirties of the 18th century, but in the Middle Ages its consumption was limited to several tens of kilograms. The scope of use was narrow: for alchemical experiments, the purification of precious metals and in pharmacy. Small amounts of concentrated sulfuric acid were used in the manufacture of special matches that contained berthollet's salt.

In Russia, vitriol acid appeared only in the 17th century.

In Birmingham, England, John Roebuck in 1746 adapted the above method for producing sulfuric acid and started production. In doing so, he used strong large leaded chambers, which were cheaper than glass containers.

In industry, this method held its ground for almost 200 years, and 65% sulfuric acid was obtained in the chambers.

Over time, the English Glover and the French chemist Gay-Lussac improved the process itself, and sulfuric acid was obtained with a concentration of 78%. But for the production of, for example, dyes, such an acid was not suitable.

In the early 19th century, new ways of oxidizing sulfur dioxide to sulfuric anhydride were discovered.

Initially, this was done using nitrogen oxides, and then platinum was used as a catalyst. These two methods of oxidizing sulfur dioxide have been further developed. Oxidation of sulfur dioxide on platinum and other catalysts has come to be called the contact method. And the oxidation of this gas with nitrogen oxides is called the nitrous method for producing sulfuric acid.

The British acetic acid trader Peregrine Phillips patented an economical process for the production of sulfur (VI) oxide and concentrated sulfuric acid only in 1831, and it is he who is known to the world today as a contact method for its production.

Superphosphate production began in 1864.

In the eighties of the nineteenth century in Europe, the production of sulfuric acid reached 1 million tons. The main producers were Germany and England, producing 72% of the total volume of sulfuric acid in the world.

The transportation of sulfuric acid is a laborious and responsible undertaking.

Sulfuric acid belongs to a class of hazardous chemicals, and in contact with the skin, it causes severe burns. In addition, it can cause chemical poisoning in humans. If certain rules are not observed during transportation, sulfuric acid, due to its explosiveness, can cause a lot of harm to both people and the environment.

Sulfuric acid has been assigned a hazard class 8 and must be transported by specially trained and trained professionals. An important condition for the delivery of sulfuric acid is compliance with the specially developed Rules for the carriage of dangerous goods.

Transportation by road is carried out in accordance with the following rules:

1. For transportation, special containers are made from a special steel alloy that does not react with sulfuric acid or titanium. Such containers are not oxidized. Hazardous sulfuric acid is transported in special sulfuric acid chemical tanks. They differ in design and are selected during transportation depending on the type of sulfuric acid.
2. When transporting fuming acid, specialized isothermal thermos tanks are used, in which the required temperature regime is maintained to preserve the chemical properties of the acid.
3. If ordinary acid is transported, then a sulfuric acid tank is selected.
4. Transportation of sulfuric acid by road, such as fuming, anhydrous, concentrated, for batteries, glover, is carried out in special containers: tanks, barrels, containers.
5. The transportation of dangerous goods can only be carried out by drivers who have an ADR certificate in their hands.
6. The travel time has no restrictions, since during transportation you must strictly adhere to the permissible speed.
7. During transportation, a special route is built, which should run, bypassing crowded places and production facilities.
8. Transport must have special markings and danger signs.

Dangerous properties of sulfuric acid for humans

Sulfuric acid poses an increased danger to the human body. Its toxic effect occurs not only upon direct contact with the skin, but upon inhalation of its vapors, when sulfur dioxide is released. Dangerous exposure extends to:

• Respiratory system;
• Skin integuments;
• Mucous membranes.

Arsenic, which is often a part of sulfuric acid, can increase the intoxication of the body.

Important! As you know, severe burns occur when acid comes into contact with the skin. Poisoning with sulfuric acid vapors is no less dangerous. A safe dose of sulfuric acid in the air is only 0.3 mg per 1 square meter.

If sulfuric acid gets on the mucous membranes or on the skin, a severe burn appears that does not heal well. If the burn is impressive in scale, the victim develops a burn disease, which can even lead to death if qualified medical assistance is not provided in a timely manner.

Important! For an adult, the lethal dose of sulfuric acid is only 0.18 cm3 per liter.

Of course, it is problematic to “experience” the toxic effect of acid in everyday life. Most often, acid poisoning occurs due to neglect of industrial safety when working with a solution.

Mass poisoning with sulfuric acid vapors can occur due to technical malfunctions in production or carelessness, and a massive release into the atmosphere occurs. To prevent such situations, special services work, whose task is to control the functioning of production where hazardous acid is used.

What symptoms are observed with sulfuric acid intoxication

If the acid has been ingested:

• Pain in the area of ​​the digestive organs.
• Nausea and vomiting.
• Stool disorder, as a result of severe intestinal disorders.
• Heavy salivation.
• Due to the toxic effects on the kidneys, the urine becomes reddish.
• Swelling of the larynx and throat. There are wheezing, hoarseness. It can be fatal from suffocation.
• Brown spots appear on the gums.
• The skin turns blue.

With a burn of the skin, there can be all the complications inherent in a burn disease.

When poisoning with vapors, the following picture is observed:

• Burns of the mucous membrane of the eyes.
• Nose bleed.
• Burns of the mucous membranes of the respiratory tract. In this case, the victim experiences a strong pain symptom.
• Swelling of the larynx with symptoms of suffocation (lack of oxygen, the skin turns blue).
• If the poisoning is severe, then there may be nausea and vomiting.

It's important to know! Acid poisoning after ingestion is much more dangerous than intoxication from inhalation of vapors.

First aid and therapeutic procedures for the defeat of sulfuric acid

Proceed as follows for contact with sulfuric acid:

• The first step is to call an ambulance. If the liquid gets inside, then wash the stomach with warm water. After that, in small sips, you will need to drink 100 grams of sunflower or olive oil. In addition, you should swallow a piece of ice, drink milk or burnt magnesia. This must be done to reduce the concentration of sulfuric acid and alleviate the human condition.
• If acid gets into your eyes, you need to rinse them with running water, and then drip with a solution of dicaine and novocaine.
• If acid gets on the skin, rinse the burned area well under running water and apply a bandage with soda. It takes about 10-15 minutes to rinse.
• In case of poisoning with vapors, you need to go out into fresh air, and also rinse the affected mucous membranes with water as far as available.

In a hospital setting, treatment will depend on the area of ​​the burn and the degree of poisoning. Anesthesia is carried out only with novocaine. In order to avoid the development of infection in the area of ​​infection, the patient is selected a course of antibiotic therapy.

For gastric bleeding, plasma is injected or blood is transfused. The source of bleeding can be eliminated by surgery.

1. Sulfuric acid in pure 100% form occurs in nature. For example, in Italy, Sicily, in the Dead Sea, you can see a unique phenomenon - sulfuric acid seeps right from the bottom! Here's what happens: pyrite from the earth's crust serves in this case as a raw material for its formation. This place is also called the Lake of Death, and even insects are afraid to fly up to it!
2. After large volcanic eruptions, droplets of sulfuric acid can often be found in the earth's atmosphere, and in such cases, the "culprit" can bring negative consequences for the environment and cause serious climate changes.
3. Sulfuric acid is an active absorber of water, therefore it is used as a gas desiccant. In the old days, so that the windows did not fog up in the rooms, this acid was poured into jars and placed between the glass of window openings.
4. It is sulfuric acid that is the main cause of acid rain. The main cause of acid rain is air pollution with sulfur dioxide, which, when dissolved in water, forms sulfuric acid. In turn, sulfur dioxide is released when fossil fuels are burned. In acid rain, studied in recent years, the content of nitric acid has increased. The reason for this is the reduction in sulfur dioxide emissions. Despite this fact, sulfuric acid remains the main cause of acid rain.

We offer you a video selection of interesting experiments with sulfuric acid.

Consider the reaction of sulfuric acid when it is poured into sugar. In the first seconds when sulfuric acid enters the flask with sugar, the mixture darkens. After a few seconds, the substance turns black. Next comes the fun part. The mass begins to grow rapidly and climb out of the flask. At the exit, we get a proud substance, similar to porous charcoal, exceeding the initial volume by 3-4 times.

The author of the video suggests comparing the reaction of Coca-Cola with hydrochloric acid and sulfuric acid. When mixing Coca-Cola with hydrochloric acid, no visual changes are observed, but when mixed with sulfuric acid, Coca-Cola begins to boil.

An interesting interaction can be observed when sulfuric acid gets on toilet paper. Toilet paper is composed of cellulose. When acid hits, the cellulose molecule is instantly destroyed with the release of free carbon. Similar charring can be observed when acid gets on the wood.

I add a small piece of potassium to the flask with concentrated acid. In the first second, smoke is released, after which the metal instantly flares up, ignites and explodes, breaking into pieces.

In the next experiment, when sulfuric acid hits a match, it flares up. In the second part of the experiment, an aluminum foil with acetone and a match inside is immersed. The foil is instantly heated with the release of a huge amount of smoke and its complete dissolution.

An interesting effect is observed when baking soda is added to sulfuric acid. The soda turns yellow instantly. The reaction takes place with a violent boiling and an increase in volume.

We strongly advise against carrying out all the above experiments at home. Sulfuric acid is a very corrosive and toxic substance. Such experiments must be carried out in special rooms that are equipped with forced ventilation. The gases released in reactions with sulfuric acid are very toxic and can cause respiratory tract damage and poisoning of the body. In addition, similar experiments are carried out in personal protective equipment for the skin and respiratory organs. Take care of yourself!

Acids are chemical compounds consisting of hydrogen atoms and acidic residues, for example, SO4, SO3, PO4, etc. They are inorganic and organic. The first include hydrochloric, phosphoric, sulfide, nitric, sulfuric acid. To the second - acetic, palmitic, formic, stearic, etc.

What is sulfuric acid

This acid consists of two hydrogen atoms and an acidic SO4 residue. It has the formula H2SO4.

Sulfuric acid, or, as it is also called, sulfate, refers to inorganic oxygen-containing diacids. This substance is considered one of the most aggressive and chemically active. In most chemical reactions, it acts as an oxidizing agent. This acid can be used in concentrated or diluted form, in these two cases it has slightly different chemical properties.

Physical properties

Sulfuric acid under normal conditions has a liquid state, its boiling point is about 279.6 degrees Celsius, the freezing point, when it turns into solid crystals, is about -10 degrees for one hundred percent and about -20 for 95 percent.

Pure one hundred percent sulfate acid is an odorless and colorless oily liquid substance that has almost twice the density of water - 1840 kg / m3.

Chemical properties of sulfate acid

Sulfuric acid reacts with metals, their oxides, hydroxides and salts. Diluted with water in various proportions, it can behave in different ways, therefore, let us consider in more detail the properties of a concentrated and weak solution of sulfuric acid separately.

Concentrated sulfuric acid solution

A concentrated solution is a solution that contains from 90 percent sulfate acid. Such a sulfuric acid solution is capable of reacting even with low-active metals, as well as with non-metals, hydroxides, oxides, and salts. The properties of such a sulfate acid solution are similar to those of concentrated nitrate acid.

Interaction with metals

During the chemical reaction of a concentrated solution of sulfate acid with metals located to the right of hydrogen in the electrochemical series of metal voltages (that is, with not the most active ones), such substances are formed: sulfate of the metal with which it interacts, water and sulfur dioxide. Metals, as a result of interaction with which the listed substances are formed, include copper (cuprum), mercury, bismuth, silver (argentum), platinum and gold (aurum).

Interaction with inactive metals

With metals that are to the left of hydrogen in the series of voltages, concentrated sulfuric acid behaves a little differently. As a result of such a chemical reaction, the following substances are formed: sulfate of a certain metal, hydrogen sulfide, or pure sulfur and water. The metals with which a similar reaction takes place also include iron (ferum), magnesium, mangan, beryllium, lithium, barium, calcium and all the others that are in the series of voltages to the left of hydrogen, except for aluminum, chromium, nickel and titanium - with them concentrated sulfate acid does not interact.

Interaction with non-metals

This substance is a strong oxidizing agent, therefore it is able to participate in redox chemical reactions with non-metals, such as, for example, carbon (carbon) and sulfur. As a result of such reactions, water is necessarily released. When this substance is added to carbon, carbon dioxide and sulphur dioxide are also released. And if we add acid to sulfur, we get only sulfur dioxide and water. In such a chemical reaction, sulfate acid acts as an oxidizing agent.

Interaction with organic substances

Carbonization can be distinguished among the reactions of sulfuric acid with organic substances. This process occurs when a given substance collides with paper, sugar, fibers, wood, etc. In this case, carbon is released in any case. The carbon formed during the reaction can partially react with sulfuric acid in excess of it. The photo shows the reaction of sugar with a solution of sulfate acid of medium concentration.

Reactions with salts

Also, a concentrated solution of H2SO4 reacts with dry salts. In this case, a standard exchange reaction occurs, in which a metal sulfate is formed, which was present in the structure of the salt, and an acid with a residue that was in the composition of the salt. However, concentrated sulfuric acid does not react with salt solutions.

Interaction with other substances

Also, this substance can react with metal oxides and their hydroxides, in these cases, exchange reactions occur, in the first, metal sulfate and water are released, in the second - the same thing.

Chemical properties of a weak solution of sulfate acid

Diluted sulfuric acid reacts with many substances and has the same properties as all acids. It, in contrast to concentrated, interacts only with active metals, that is, those that are to the left of hydrogen in a series of voltages. In this case, the same substitution reaction occurs as in the case of any acid. This produces hydrogen. Also, such an acid solution interacts with salt solutions, as a result of which an exchange reaction occurs, already discussed above, with oxides - just like concentrated, with hydroxides - the same way. In addition to ordinary sulfates, there are also hydrosulfates, which are the product of the interaction of hydroxide and sulfuric acid.

How to know if the solution contains sulfuric acid or sulfates

To determine whether these substances are present in the solution, a special qualitative reaction for sulfate ions is used, which allows you to find out. It consists in adding barium or its compounds to the solution. This may result in a white precipitate (barium sulfate), which indicates the presence of sulfates or sulfuric acid.

How sulfuric acid is mined

The most widespread method of industrial production of this substance is its extraction from iron pyrite. This process takes place in three stages, at each of which a certain chemical reaction takes place. Let's consider them. First, oxygen is added to the pyrite, as a result of which ferum oxide and sulfur dioxide are formed, which is used for further reactions. This interaction takes place at high temperatures. This is followed by a stage in which sulfur trioxide is obtained by adding oxygen in the presence of a catalyst, which is vanadium oxide. Now, in the last stage, water is added to the resulting substance, whereby sulfate acids are obtained. This is the most common process for the industrial production of sulfate acid, it is used most often because pyrite is the most affordable raw material, suitable for the synthesis of the substance described in this article. Sulfuric acid obtained by this process is used in various industries - both in chemical and in many others, for example, in oil refining, ore dressing, etc. Also, its use is often provided for in the technology of manufacturing many synthetic fibers. ...

Physical properties of sulfuric acid:
Heavy oily liquid ("vitriol oil");
density 1.84 g / cm3; non-volatile, well soluble in water - with strong heating; t ° pl. = 10.3 ° C, bp t ° = 296 ° С, very hygroscopic, has dehydrating properties (charring of paper, wood, sugar).

The heat of hydration is so high that the mixture can boil, splatter and cause burns. Therefore, it is necessary to add acid to water, and not vice versa, since when water is added to acid, lighter water will end up on the surface of the acid, where all the released heat will be concentrated.

Industrial production of sulfuric acid (contact method):

1) 4FeS 2 + 11O 2 → 2Fe 2 O 3 + 8SO 2

2) 2SO 2 + O 2 V 2 O 5 → 2SO 3

3) nSO 3 + H 2 SO 4 → H 2 SO 4 nSO 3 (oleum)

Crushed purified wet pyrite (pyrite) is poured from above into the kiln for roasting in " fluidized bed". Oxygen-enriched air is passed from below (counterflow principle).
Furnace gas comes out of the furnace, the composition of which is: SO 2, O 2, water vapor (the pyrite was wet) and the smallest particles of cinder (iron oxide). The gas is purified from impurities of solid particles (in a cyclone and an electrostatic precipitator) and water vapor (in a drying tower).
In the contact apparatus, sulfur dioxide is oxidized using a catalyst V 2 O 5 (vanadium pentoxide) to increase the reaction rate. The oxidation process of one oxide to another is reversible. Therefore, the optimal conditions for the direct reaction are selected - increased pressure (because the direct reaction proceeds with a decrease in the total volume) and the temperature is not higher than 500 C (because the reaction is exothermic).

In the absorption tower, sulfur (VI) oxide is absorbed by concentrated sulfuric acid.
Absorption by water is not used, because sulfur oxide dissolves in water with the release of a large amount of heat, so the resulting sulfuric acid boils and turns into steam. In order to avoid the formation of sulfuric acid mist, use 98% concentrated sulfuric acid. Sulfur oxide dissolves very well in such an acid, forming oleum: H 2 SO 4 nSO 3

Chemical properties of sulfuric acid:

H 2 SO 4 is a strong dibasic acid, one of the strongest mineral acids, because of the high polarity, the H - O bond is easily broken.

1) In an aqueous solution, sulfuric acid dissociates , forming a hydrogen ion and an acid residue:
H 2 SO 4 = H + + HSO 4 -;
HSO 4 - = H + + SO 4 2-.
Summary equation:
H 2 SO 4 = 2H + + SO 4 2-.

2) Interaction of sulfuric acid with metals:
Diluted sulfuric acid dissolves only metals in the series of voltages to the left of hydrogen:
Zn 0 + H 2 +1 SO 4 (split) → Zn +2 SO 4 + H 2

3) Reaction between sulfuric acidwith basic oxides:
CuO + H 2 SO 4 → CuSO 4 + H 2 O

4) Interaction of sulfuric acid withhydroxides:
H 2 SO 4 + 2NaOH → Na 2 SO 4 + 2H 2 O
H 2 SO 4 + Cu (OH) 2 → CuSO 4 + 2H 2 O

5) Exchange reactions with salts:
BaCl 2 + H 2 SO 4 → BaSO 4 ↓ + 2HCl
The formation of a white precipitate BaSO 4 (insoluble in acids) is used for the detection of sulfuric acid and soluble sulfates (qualitative reaction for sulfate ion).

Special properties of concentrated H 2 SO 4:

1) Concentrated sulfuric acid is strong oxidizing agent ; when interacting with metals (except for Au, Pt), reduce to S +4 O 2, S 0 or H 2 S -2, depending on the activity of the metal. Does not react with Fe, Al, Cr without heating - passivation. When interacting with metals with variable valence, the latter are oxidized to higher oxidation states than in the case of a dilute acid solution: Fe 0→ Fe 3+, Cr 0→ Cr 3+, Mn 0→Mn 4+,Sn 0→ Sn 4+

Active metal

8 Al + 15 H 2 SO 4 (conc.) → 4Al 2 (SO 4) 3 + 12H 2 O + 3 H 2 S
4│2Al 0 - 6 e- → 2Al 3+ - oxidation
3│ S 6+ + 8e → S 2– recovery

4Mg + 5H 2 SO 4 → 4MgSO 4 + H 2 S + 4H 2 O

Medium activity metal

2Cr + 4 H 2 SO 4 (conc.) → Cr 2 (SO 4) 3 + 4 H 2 O + S
1│ 2Cr 0 - 6e → 2Cr 3+ - oxidation
1│ S 6+ + 6e → S 0 - recovery

Inactive metal

2Bi + 6H 2 SO 4 (conc.) → Bi 2 (SO 4) 3 + 6H 2 O + 3 SO 2
1│ 2Bi 0 - 6e → 2Bi 3+ - oxidation
3│ S 6+ + 2e → S 4+ - recovery

2Ag + 2H 2 SO 4 → Ag 2 SO 4 + SO 2 + 2H 2 O

2) Concentrated sulfuric acid oxidizes some non-metals, as a rule, to the maximum oxidation state, itself is reduced toS +4O 2:

С + 2H 2 SO 4 (conc) → CO 2 + 2SO 2 + 2H 2 O

S + 2H 2 SO 4 (conc) → 3SO 2 + 2H 2 O

2P + 5H 2 SO 4 (conc) → 5SO 2 + 2H 3 PO 4 + 2H 2 O

3) Oxidation of complex substances:
Sulfuric acid oxidizes HI and HBr to free halogens:
2 КВr + 2Н 2 SO 4 = К 2 SO 4 + SO 2 + Вr 2 + 2Н 2 О
2 КI + 2Н 2 SO 4 = К 2 SO 4 + SO 2 + I 2 + 2Н 2 О
Concentrated sulfuric acid cannot oxidize chloride ions to free chlorine, which makes it possible to obtain HCl by the exchange reaction:
NaCl + H 2 SO 4 (conc.) = NaHSO 4 + HCl

Sulfuric acid removes chemically bound water from organic compounds containing hydroxyl groups. Dehydration of ethyl alcohol in the presence of concentrated sulfuric acid leads to the production of ethylene:
C 2 H 5 OH = C 2 H 4 + H 2 O.

The charring of sugar, cellulose, starch and other carbohydrates in contact with sulfuric acid is also explained by their dehydration:
C 6 H 12 O 6 + 12H 2 SO 4 = 18H 2 O + 12SO 2 + 6CO 2.