Every person in chemistry class studied acids. One of them is called sulfuric acid and is designated HSO 4. About what are the properties of sulfuric acid, our article will tell.

Physical properties of sulfuric acid

Pure sulfuric acid or monohydrate is a colorless oily liquid that solidifies into a crystalline mass at +10°C. Sulfuric acid intended for reactions contains 95% H 2 SO 4 and has a density of 1.84 g/cm 3 . 1 liter of such acid weighs 2 kg. Acid hardens at -20°C. The heat of fusion is 10.5 kJ/mol at a temperature of 10.37°C.

The properties of concentrated sulfuric acid are varied. For example, when dissolving this acid in water, a large amount of heat (19 kcal / mol) will be released due to the formation of hydrates. These hydrates can be isolated from solution at low temperatures in solid form.

Sulfuric acid is one of the most basic products in the chemical industry. It is intended for the production of mineral fertilizers (ammonium sulfate, superphosphate), various salts and acids, detergents and medicines, artificial fibers, dyes, explosives. Sulfuric acid is also used in metallurgy (for example, the decomposition of uranium ores), for the purification of petroleum products, for drying gases, and so on.

Chemical properties of sulfuric acid

The chemical properties of sulfuric acid are:

1. Interaction with metals:
   • dilute acid dissolves only those metals that are to the left of hydrogen in a series of voltages, for example H 2 +1 SO 4 + Zn 0 \u003d H 2 O + Zn + 2 SO 4;
   • the oxidizing properties of sulfuric acid are great. When interacting with various metals (except Pt, Au), it can be reduced to H 2 S -2, S +4 O 2 or S 0, for example:
   • 2H 2 +6 SO 4 + 2Ag 0 = S +4 O 2 + Ag 2 +1 SO 4 + 2H 2 O;
   • 5H 2 +6 SO 4 + 8Na 0 \u003d H 2 S -2 + 4Na 2 +1 SO 4 + 4H 2 O;
2. Concentrated acid H 2 S +6 O 4 also reacts (when heated) with some non-metals, while turning into sulfur compounds with a lower oxidation state, for example:
   • 2H 2 S +6 O 4 + C 0 = 2S +4 O 2 + C +4 O 2 + 2H 2 O;
   • 2H 2 S +6 O 4 + S 0 = 3S +4 O 2 + 2H 2 O;
   • 5H 2 S +6 O 4 + 2P 0 = 2H 3 P +5 O 4 + 5S +4 O 2 + 2H 2 O;
3. With basic oxides:
   • H 2 SO 4 + CuO = CuSO 4 + H 2 O;
4. With hydroxides:
   • Cu(OH) 2 + H 2 SO 4 = CuSO 4 + 2H 2 O;
   • 2NaOH + H 2 SO 4 = Na 2 SO 4 + 2H 2 O;
5. Interaction with salts in exchange reactions:
   • H 2 SO 4 + BaCl 2 \u003d 2HCl + BaSO 4;

The formation of BaSO 4 (white precipitate, insoluble in acids) is used to determine this acid and soluble sulfates.

A monohydrate is an ionizing solvent having an acidic character. It is very good to dissolve sulfates of many metals in it, for example:

• 2H 2 SO 4 + HNO 3 \u003d NO 2 + + H 3 O + + 2HSO 4 -;
• HClO 4 + H 2 SO 4 \u003d ClO 4 - + H 3 SO 4 +.

A concentrated acid is a fairly strong oxidizing agent, especially when heated, for example 2H 2 SO 4 + Cu = SO 2 + CuSO 4 + H 2 O.

Acting as an oxidizing agent, sulfuric acid is usually reduced to SO 2 . But it can be reduced to S and even to H 2 S, for example H 2 S + H 2 SO 4 = SO 2 + 2H 2 O + S.

The monohydrate almost cannot conduct electricity. Conversely, aqueous acid solutions are good conductors. Sulfuric acid strongly absorbs moisture, so it is used to dry various gases. As a desiccant, sulfuric acid acts as long as the water vapor pressure above its solution is less than its pressure in the gas being dried.

If a dilute solution of sulfuric acid is boiled, water will be removed from it, while the boiling point will rise to 337 ° C, for example, when sulfuric acid at a concentration of 98.3% is started to be distilled. Conversely, from solutions that are more concentrated, excess sulfuric anhydride evaporates. Steam boiling at a temperature of 337 ° C acid is partially decomposed into SO 3 and H 2 O, which, upon cooling, will again be combined. The high boiling point of this acid is suitable for use in separating volatile acids from their salts when heated.

Acid Handling Precautions

When handling sulfuric acid, extreme care must be taken. When this acid comes into contact with the skin, the skin becomes white, then brownish and redness appears. The surrounding tissue swells up. If this acid comes into contact with any part of the body, it must be quickly washed off with water, and the burned area should be lubricated with a solution of soda.

Now you know that sulfuric acid, whose properties are well studied, is simply indispensable for a variety of production and mining.

Sulfur is a chemical element that is in the sixth group and third period of the periodic table. In this article, we will take a detailed look at its chemical and production, use, and so on. The physical characteristic includes such features as color, electrical conductivity level, sulfur boiling point, etc. The chemical one describes its interaction with other substances.

Sulfur in terms of physics

This is a fragile substance. Under normal conditions, it is in a solid state of aggregation. Sulfur has a lemon yellow color.

And for the most part, all its compounds have yellow tints. Does not dissolve in water. It has low thermal and electrical conductivity. These features characterize it as a typical non-metal. Despite the fact that the chemical composition of sulfur is not at all complicated, this substance can have several variations. It all depends on the structure of the crystal lattice, with the help of which atoms are connected, but they do not form molecules.

So, the first option is rhombic sulfur. She is the most stable. The boiling point of this type of sulfur is four hundred and forty-five degrees Celsius. But in order for a given substance to pass into a gaseous state of aggregation, it must first pass through a liquid state. So, the melting of sulfur occurs at a temperature that is one hundred and thirteen degrees Celsius.

The second option is monoclinic sulfur. It is a needle-shaped crystals with a dark yellow color. The melting of sulfur of the first type, and then its slow cooling leads to the formation of this type. This variety has almost the same physical characteristics. For example, the boiling point of sulfur of this type is still the same four hundred and forty-five degrees. In addition, there is such a variety of this substance as plastic. It is obtained by pouring into cold water heated almost to a boil rhombic. The boiling point of sulfur of this type is the same. But the substance has the property of stretching like rubber.

Another component of the physical characteristic that I would like to talk about is the ignition temperature of sulfur.

This indicator may vary depending on the type of material and its origin. For example, the ignition temperature of technical sulfur is one hundred and ninety degrees. This is a rather low figure. In other cases, the flash point of sulfur can be two hundred and forty-eight degrees and even two hundred and fifty-six. It all depends on what material it was mined from, what density it has. But we can conclude that the combustion temperature of sulfur is quite low, compared with other chemical elements, it is a flammable substance. In addition, sometimes sulfur can combine into molecules consisting of eight, six, four or two atoms. Now, having considered sulfur from the point of view of physics, let's move on to the next section.

Chemical characterization of sulfur

This element has a relatively low atomic mass, it is equal to thirty-two grams per mole. The characteristic of the sulfur element includes such a feature of this substance as the ability to have different degrees of oxidation. In this it differs from, say, hydrogen or oxygen. Considering the question of what is the chemical characteristic of the sulfur element, it is impossible not to mention that, depending on the conditions, it exhibits both reducing and oxidizing properties. So, in order, consider the interaction of a given substance with various chemical compounds.

Sulfur and simple substances

Simple substances are substances that contain only one chemical element. Its atoms may combine into molecules, as, for example, in the case of oxygen, or they may not combine, as is the case with metals. So, sulfur can react with metals, other non-metals and halogens.

Interaction with metals

A high temperature is required to carry out this kind of process. Under these conditions, an addition reaction occurs. That is, metal atoms combine with sulfur atoms, thus forming complex substances sulfides. For example, if you heat two moles of potassium by mixing them with one mole of sulfur, you get one mole of the sulfide of this metal. The equation can be written in the following form: 2K + S = K 2 S.

Reaction with oxygen

This is sulfur burning. As a result of this process, its oxide is formed. The latter can be of two types. Therefore, the combustion of sulfur can occur in two stages. The first is when one mole of sulfur and one mole of oxygen form one mole of sulfur dioxide. You can write the equation for this chemical reaction as follows: S + O 2 \u003d SO 2. The second stage is the addition of one more oxygen atom to the dioxide. This happens if you add one mole of oxygen to two moles at high temperature. The result is two moles of sulfur trioxide. The equation for this chemical interaction looks like this: 2SO 2 + O 2 = 2SO 3. As a result of this reaction, sulfuric acid is formed. So, by carrying out the two processes described, it is possible to pass the resulting trioxide through a jet of water vapor. And we get The equation for such a reaction is written as follows: SO 3 + H 2 O \u003d H 2 SO 4.

Interaction with halogens

Chemical like other non-metals, allow it to react with this group of substances. It includes compounds such as fluorine, bromine, chlorine, iodine. Sulfur reacts with any of them, except for the last one. As an example, we can cite the process of fluorination of the element of the periodic table we are considering. By heating the mentioned non-metal with a halogen, two variations of fluoride can be obtained. The first case: if we take one mole of sulfur and three moles of fluorine, we get one mole of fluoride, the formula of which is SF 6. The equation looks like this: S + 3F 2 = SF 6. In addition, there is a second option: if we take one mole of sulfur and two moles of fluorine, we get one mole of fluoride with the chemical formula SF 4 . The equation is written in the following form: S + 2F 2 = SF 4 . As you can see, it all depends on the proportions in which the components are mixed. In exactly the same way, it is possible to carry out the process of chlorination of sulfur (two different substances can also be formed) or bromination.

Interaction with other simple substances

The characterization of the element sulfur does not end there. The substance can also enter into a chemical reaction with hydrogen, phosphorus and carbon. Due to the interaction with hydrogen, sulfide acid is formed. As a result of its reaction with metals, their sulfides can be obtained, which, in turn, are also obtained by direct reaction of sulfur with the same metal. The addition of hydrogen atoms to sulfur atoms occurs only under conditions of very high temperature. When sulfur reacts with phosphorus, its phosphide is formed. It has the following formula: P 2 S 3. In order to get one mole of this substance, you need to take two moles of phosphorus and three moles of sulfur. When sulfur interacts with carbon, the carbide of the considered non-metal is formed. Its chemical formula looks like this: CS 2. In order to get one mole of this substance, you need to take one mole of carbon and two moles of sulfur. All the addition reactions described above occur only when the reactants are heated to high temperatures. We have considered the interaction of sulfur with simple substances, now let's move on to the next point.

Sulfur and complex compounds

Compounds are those substances whose molecules consist of two (or more) different elements. The chemical properties of sulfur allow it to react with compounds such as alkalis, as well as concentrated sulphate acid. Its reactions with these substances are rather peculiar. First, consider what happens when the non-metal in question is mixed with alkali. For example, if we take six moles and add three moles of sulfur to them, we get two moles of potassium sulfide, one mole of this metal sulfite and three moles of water. This kind of reaction can be expressed by the following equation: 6KOH + 3S \u003d 2K 2 S + K2SO 3 + 3H 2 O. By the same principle, the interaction occurs if you add Next, consider the behavior of sulfur when a concentrated solution of sulfate acid is added to it. If we take one mole of the first and two moles of the second substance, we get the following products: sulfur trioxide in the amount of three moles, and also water - two moles. This chemical reaction can only take place when the reactants are heated to a high temperature.

Obtaining the considered non-metal

There are several main methods by which sulfur can be extracted from a variety of substances. The first method is to isolate it from pyrite. The chemical formula of the latter is FeS 2 . When this substance is heated to a high temperature without access to oxygen, another iron sulfide - FeS - and sulfur can be obtained. The reaction equation is written as follows: FeS 2 \u003d FeS + S. The second method of obtaining sulfur, which is often used in industry, is the combustion of sulfur sulfide under the condition of a small amount of oxygen. In this case, you can get the considered non-metal and water. To carry out the reaction, you need to take the components in a molar ratio of two to one. As a result, we get the final products in proportions of two to two. The equation for this chemical reaction can be written as follows: 2H 2 S + O 2 \u003d 2S + 2H 2 O. In addition, sulfur can be obtained during various metallurgical processes, for example, in the production of metals such as nickel, copper and others.

Industrial use

The non-metal we are considering has found its widest application in the chemical industry. As mentioned above, here it is used to obtain sulfate acid from it. In addition, sulfur is used as a component for the manufacture of matches, due to the fact that it is a flammable material. It is also indispensable in the production of explosives, gunpowder, sparklers, etc. In addition, sulfur is used as one of the ingredients in pest control products. In medicine, it is used as a component in the manufacture of drugs for skin diseases. Also, the substance in question is used in the production of various dyes. In addition, it is used in the manufacture of phosphors.

Electronic structure of sulfur

As you know, all atoms consist of a nucleus, in which there are protons - positively charged particles - and neutrons, i.e. particles that have a zero charge. Electrons revolve around the nucleus with a negative charge. For an atom to be neutral, it must have the same number of protons and electrons in its structure. If there are more of the latter, this is already a negative ion - an anion. If, on the contrary, the number of protons is greater than the number of electrons, this is a positive ion, or cation. The sulfur anion can act as an acid residue. It is part of the molecules of substances such as sulfide acid (hydrogen sulfide) and metal sulfides. An anion is formed during electrolytic dissociation, which occurs when a substance is dissolved in water. In this case, the molecule decomposes into a cation, which can be represented as a metal or hydrogen ion, as well as a cation - an ion of an acid residue or a hydroxyl group (OH-).

Since the serial number of sulfur in the periodic table is sixteen, we can conclude that exactly this number of protons is located in its nucleus. Based on this, we can say that there are also sixteen electrons rotating around. The number of neutrons can be found by subtracting the serial number of the chemical element from the molar mass: 32 - 16 \u003d 16. Each electron does not rotate randomly, but along a certain orbit. Since sulfur is a chemical element that belongs to the third period of the periodic table, there are three orbits around the nucleus. The first one has two electrons, the second has eight, and the third has six. The electronic formula of the sulfur atom is written as follows: 1s2 2s2 2p6 3s2 3p4.

Prevalence in nature

Basically, the considered chemical element is found in the composition of minerals, which are sulfides of various metals. First of all, it is pyrite - iron salt; it is also lead, silver, copper luster, zinc blende, cinnabar - mercury sulfide. In addition, sulfur can also be included in the composition of minerals, the structure of which is represented by three or more chemical elements.

For example, chalcopyrite, mirabilite, kieserite, gypsum. You can consider each of them in more detail. Pyrite is a ferrum sulfide, or FeS 2 . It has a light yellow color with a golden sheen. This mineral can often be found as an impurity in lapis lazuli, which is widely used to make jewelry. This is due to the fact that these two minerals often have a common deposit. Copper shine - chalcocite, or chalcosine - is a bluish-gray substance, similar to metal. and silver luster (argentite) have similar properties: they both look like metals, have a gray color. Cinnabar is a brownish-red dull mineral with gray patches. Chalcopyrite, whose chemical formula is CuFeS 2 , is golden yellow, it is also called golden blende. Zinc blende (sphalerite) can have a color from amber to fiery orange. Mirabilite - Na 2 SO 4 x10H 2 O - transparent or white crystals. It is also called used in medicine. The chemical formula of kieserite is MgSO 4 xH 2 O. It looks like a white or colorless powder. The chemical formula of gypsum is CaSO 4 x2H 2 O. In addition, this chemical element is part of the cells of living organisms and is an important trace element.

Author Chemical Encyclopedia b.b. N.S.Zefirov

SULPHURIC ACID H 2 SO 4 , molecular weight 98.082; colorless odorless oily liquid. Very strong dibasic acid, at 18°C ​​pK a 1 - 2.8, K 2 1.2 10 -2, pK a 2 l.92; bond lengths in the molecule S=O 0.143 nm, S-OH 0.154 nm, angle HOSOH 104°, OSO 119°; boils with various, forming an azeotropic mixture (98.3% H 2 SO 4 and 1.7% H 2 O with a boiling point of 338.8 ° C; see also Table 1). SULFURIC ACID, corresponding to 100% H 2 SO 4 content, has the composition (%): H 2 SO 4 99.5, 0.18, 0.14, H 3 O + 0.09, H 2 S 2 O 7 0.04, HS 2 O 7 0.05. Miscible with water and SO 3 in all proportions. In aqueous solutions, SULFURIC ACID is almost completely dissociated into H + , and . Forms hydrates H 2 SO 4 nH 2 O, where n = 1, 2, 3, 4 and 6.5.

SO 3 solutions in SULFURIC ACID are called oleum, they form two compounds H 2 SO 4 SO 3 and H 2 SO 4 2SO 3. Oleum also contains pyrosulfuric acid, which is obtained by the reaction: H 2 SO 4 + + SO 3: H 2 S 2 O 7.

The boiling point of aqueous solutions of SULFURIC ACID to. increases with an increase in its concentration and reaches a maximum at a content of 98.3% H 2 SO 4 (Table 2). The boiling point of oleum decreases with increasing SO 3 content. With an increase in the concentration of aqueous solutions of SULFURIC ACID, the total vapor pressure over the solutions decreases and, at a content of 98.3% H 2 SO 4, reaches a minimum. With an increase in the concentration of SO 3 in oleum, the total vapor pressure above it increases. The vapor pressure over aqueous solutions of SULFURIC ACID c. and oleum can be calculated by the equation: lgp (Pa) \u003d A - B / T + 2.126, the values ​​\u200b\u200bof the coefficients A and B depend on the concentration of SULFURIC ACID c. Steam over aqueous solutions of SULFURIC ACID c. consists from a mixture of water vapor, H 2 SO 4 and SO 3, while the composition of the vapor differs from the composition of the liquid at all concentrations of SULFURIC ACID c., except for the corresponding azeotropic mixture.

With increasing temperature, the dissociation of H 2 SO 4 H 2 O + SO 3 - Q increases, the equation for the temperature dependence of the equilibrium constant lnК p = 14.74965 - 6.71464ln (298 / T) - 8, 10161 10 4 T 2 -9643.04 /T-9.4577 10 -3 T+2.19062 x 10 -6 T 2 . At normal pressure, the degree of dissociation: 10 -5 (373 K), 2.5 (473 K), 27.1 (573 K), 69.1 (673 K). The density of 100% SULFURIC ACID can be determined by the equation: d = 1.8517 - - 1.1 10 -3 t + 2 10 -6 t 2 g / cm 3. With an increase in the concentration of SULFURIC ACID solutions, their heat capacity decreases and reaches a minimum for 100% SULFURIC ACID, while the heat capacity of oleum increases with increasing SO 3 content.

With an increase in concentration and a decrease in temperature, the thermal conductivity l decreases: l \u003d 0.518 + 0.0016t - (0.25 + + t / 1293) C / 100, where C is the concentration of SULFURIC ACID c., in%. Max. viscosity has oleum H 2 SO 4 SO 3, with increasing temperature h decreases. Electric the resistance of SULFURIC ACID to. is minimal at a concentration of 30 and 92% H 2 SO 4 and maximum at a concentration of 84 and 99.8% H 2 SO 4 . For oleum min. r at a concentration of 10% SO 3 . With an increase in temperature, r SULFURIC ACID increases. Dielectric permeability 100% SULFURIC ACID room 101 (298.15 K), 122 (281.15 K); cryoscopic constant 6.12, ebulioscopic. constant 5.33; vapor diffusion coefficient SULFURIC ACID in air changes with temperature; D \u003d 1.67 10 -5 T 3/2 cm 2 / s.

SULFURIC ACID is a fairly strong oxidizing agent, especially when heated; oxidizes HI and partially HBr to free halogens, carbon to CO 2, S to SO 2, oxidizes many metals (Cu, Hg, etc.). In this case, SULFURIC ACID is reduced to SO 2, and the most powerful reducing agents are reduced to S and H 2 S. Conc. H 2 SO 4 is partially reduced by H 2 , which is why it cannot be used for drying it. Diff. H 2 SO 4 interaction with all metals that are in the electrochemical series of voltages to the left of hydrogen, with the release of H 2 . Oxidize properties for dilute H 2 SO 4 are uncharacteristic. SULFURIC ACID gives two series of salts: medium sulfates and acidic hydrosulfates (see Inorganic sulfates), as well as ethers (see Organic sulfates). Peroxomonosulphuric (Caro's acid) H 2 SO 5 and peroxodisulfuric H 2 S 2 O 8 acids are known (see Sulfur).

Receipt. The raw materials for obtaining SULFURIC ACID are: S, metal sulfides, H 2 S, exhaust gases from thermal power plants, sulfates of Fe, Ca, etc. Main. stages of obtaining SULFURIC ACID k.: 1) roasting of raw materials to obtain SO 2 ; 2) oxidation of SO 2 to SO 3 (conversion); 3) SO 3 absorption. In industry, two methods are used to obtain SULFURIC ACID, which differ in the way SO 2 is oxidized, contact using solid catalysts (contacts) and nitrous, with nitrogen oxides. To obtain SULFURIC ACID by the contact method, modern plants use vanadium catalysts that have displaced Pt and Fe oxides. Pure V 2 O 5 has a weak catalytic activity, which sharply increases in the presence of alkali metal salts, with K salts having the most influence. 7 V 2 O 5 and K 2 S 2 O 7 V 2 O 5 , decomposing at 315-330, 365-380 and 400-405 °C, respectively). The active component under catalysis is in a molten state.

The scheme for the oxidation of SO 2 to SO 3 can be represented as follows:

At the first stage, equilibrium is reached, the second stage is slow and determines the speed of the process.

The production of SULFURIC ACID from sulfur by the method of double contact and double absorption (Fig. 1) consists of the following stages. The air after cleaning from dust is supplied by a gas blower to the drying tower, where it is dried with 93-98% SULFURIC ACID to a moisture content of 0.01% by volume. The dried air enters the sulfur furnace after pre-heating. heating in one of the heat exchangers of the contact unit. The furnace burns sulfur supplied by nozzles: S + O 2 : SO 2 + + 297.028 kJ. The gas containing 10-14% by volume of SO 2 is cooled in the boiler and, after dilution with air to a SO 2 content of 9-10% by volume at 420 ° C, enters the contact apparatus for the first stage of conversion, which proceeds on three layers of catalyst (SO 2 + V 2 O 2 : : SO 3 + 96.296 kJ), after which the gas is cooled in heat exchangers. Then the gas containing 8.5-9.5% SO 3 at 200 ° C enters the first stage of absorption into the absorber, irrigated with oleum and 98% SULFURIC ACID to .: SO 3 + H 2 O: H 2 SO 4 + + 130.56 kJ. Next, the gas is cleaned from splashes of SULFURIC ACID, heated to 420 ° C and enters the second stage of conversion, which takes place on two layers of catalyst. Before the second stage of absorption, the gas is cooled in the economizer and fed into the second stage absorber, irrigated with 98% SULFURIC ACID, and then, after cleaning from splashes, it is released into the atmosphere.

Rice. 1. Scheme for the production of sulfuric acid from sulfur: 1-sulfuric furnace; 2-heat recovery boiler; 3 - economizer; 4-starter firebox; 5, 6-heat exchangers of the starting furnace; 7-pin device; 8-heat exchangers; 9-oleum absorber; 10 drying tower; 11 and 12, respectively, the first and second monohydrate absorbers; 13-collectors of acid.

Fig.2. Scheme for the production of sulfuric acid from pyrite: 1-dish feeder; 2-furnace; 3-heat recovery boiler; 4-cyclones; 5-electrostatic precipitators; 6 washing towers; 7-wet electrostatic precipitators; 8 blow tower; 9-drying tower; 10-splash trap; 11-first monohydrate absorber; 12-heat exchange-wiki; 13 - contact device; 14-oleum absorber; 15 second monohydrate absorber; 16 refrigerators; 17 collections.

Rice. 3. Scheme for the production of sulfuric acid by the nitrous method: 1 - denitratz. tower; 2, 3-first and second products. towers; 4-oxidize. tower; 5, 6, 7-absorpt. towers; 8 - electrostatic precipitators.

The production of SULFURIC ACID from metal sulfides (Fig. 2) is much more complicated and consists of the following operations. Roasting of FeS 2 is carried out in an air-blast fluidized bed furnace: 4FeS 2 + 11O 2: 2Fe 2 O 3 + 8SO 2 + 13476 kJ. Roasting gas with a SO 2 content of 13-14%, having a temperature of 900 °C, enters the boiler, where it is cooled to 450 °C. Dust removal is carried out in a cyclone and an electrostatic precipitator. Further, the gas passes through two washing towers, irrigated with 40% and 10% SULFURIC ACID. At the same time, the gas is finally purified from dust, fluorine and arsenic. Two stages of wet electrostatic precipitators are provided for gas purification from SULFURIC ACID aerosol formed in washing towers. After drying in a drying tower, before which the gas is diluted to a content of 9% SO 2 , it is fed to the first conversion stage (3 catalyst beds) by a blower. In heat exchangers, the gas is heated up to 420 °C due to the heat of the gas coming from the first stage of the conversion. SO 2 , oxidized to 92-95% in SO 3 , goes to the first stage of absorption in oleum and monohydrate absorbers, where it is released from SO 3 . Next, the gas containing SO 2 ~ 0.5% enters the second conversion stage, which takes place on one or two catalyst layers. The gas is preliminarily heated in another group of heat exchangers up to 420 °C due to the heat of the gases coming from the second stage of catalysis. After separation of SO 3 in the second stage of absorption, the gas is released into the atmosphere.

The degree of conversion of SO 2 to SO 3 in the contact method is 99.7%, the degree of absorption of SO 3 is 99.97%. The production of SULFURIC ACID is also carried out in one stage of catalysis, while the degree of conversion of SO 2 to SO 3 does not exceed 98.5%. Before being released into the atmosphere, the gas is purified from the remaining SO 2 (see Gas purification). The productivity of modern installations is 1500-3100 tons / day.

The essence of the nitrous method (Fig. 3) is that the roasting gas, after cooling and cleaning from dust, is treated with the so-called nitrose-C. to., in which sol. nitrogen oxides. SO 2 is absorbed by nitrose, and then oxidized: SO 2 + N 2 O 3 + H 2 O: H 2 SO 4 + NO. The resulting NO is poorly soluble in nitrose and is released from it, and then partially oxidized by oxygen in the gas phase to NO 2 . The mixture of NO and NO 2 is reabsorbed by SULFURIC ACID. etc. Nitrogen oxides are not consumed in the nitrous process and are returned to production. cycle, due to incomplete absorption of their SULFURIC ACID to. they are partially carried away by the exhaust gases. Advantages of the nitrous method: simplicity of hardware design, lower cost (10-15% lower than the contact one), the possibility of 100% SO 2 processing.

The instrumentation of the tower nitrous process is simple: SO 2 is processed in 7-8 lined towers with ceramic. nozzle, one of the towers (hollow) is an adjustable oxidizer. volume. The towers have acid collectors, refrigerators, pumps that supply acid to pressure tanks above the towers. A tail fan is installed in front of the last two towers. An electrostatic precipitator serves to purify the gas from the aerosol of SULFURIC ACID. The nitrogen oxides required for the process are obtained from HNO 3 . To reduce the emission of nitrogen oxides into the atmosphere and 100% SO 2 processing, a nitrous-free SO 2 processing cycle is installed between the production and absorption zones in combination with a water-acid method for deep trapping of nitrogen oxides. The disadvantage of the nitrous method is the low quality of products: the concentration of SULFURIC ACID is 75%, the presence of nitrogen oxides, Fe, and other impurities.

To reduce the possibility of crystallization of SULFURIC ACID, during transportation and storage, standards have been established for commercial grades of SULFURIC ACID, the concentration of which corresponds to the lowest crystallization temperatures. Content SULFURIC ACID c. in tech. grades (%): tower (nitrous) 75, contact 92.5-98.0, oleum 104.5, high-percentage oleum 114.6, battery 92-94. SULFURIC ACID is stored in steel tanks up to 5000 m 3 in volume, their total capacity in the warehouse is designed for ten days of production. Oleum and SULFURIC ACID are transported in steel railway tanks. Conc. and battery SULFURIC ACID to. are transported in acid-resistant steel tanks. Tanks for the transportation of oleum are covered with thermal insulation and the oleum is heated before filling.

SULFURIC ACID is determined colorimetrically and photometrically, in the form of a suspension of BaSO 4 - phototurbidimetrically, as well as coulometrically. method.

Application. SULFURIC ACID is used in the production of mineral fertilizers, as an electrolyte in lead batteries, for the production of various mineral acids and salts, chemical fibers, dyes, smoke-forming substances and explosives, in the oil, metalworking, textile, leather, and other industries. It is used in prom. organic synthesis in dehydration reactions (obtaining diethyl ether, esters), hydration (ethanol from ethylene), sulfonation (synthetic detergents and intermediate products in the production of dyes), alkylation (obtaining isooctane, polyethylene glycol, capro-lactam), etc. The largest consumer of SULFURIC ACID is the production of mineral fertilizers. For 1 ton of P 2 O 5 phosphorus fertilizers, 2.2-3.4 tons of SULFURIC ACID are consumed, and for 1 ton of (NH 4) 2 SO 4 -0.75 tons of SULFURIC ACID. Therefore, sulfuric acid plants tend to build in a complex with factories for the production of mineral fertilizers. World production of SULFURIC ACID in 1987 reached 152 million tons.

SULFURIC ACID acid and oleum are extremely aggressive substances that affect the respiratory tract, skin, mucous membranes, cause difficulty in breathing, cough, often laryngitis, tracheitis, bronchitis, etc. MAC aerosol SULFURIC ACID acid in the air of the working area 1, 0 mg / m 3, in atm. air 0.3 mg / m 3 (max. single) and 0.1 mg / m 3 (daily average). The damaging concentration of SULFURIC ACID vapors is 0.008 mg / l (exposure 60 minutes), lethal 0.18 mg / l (60 minutes). Hazard class 2. Aerosol SULFURIC ACID can be formed in the atmosphere as a result of chemical and metallurgical emissions. industries containing S oxides and fall out as acid rain.

Literature: Handbook of sulfuric acid, ed. K. M. Malina, 2nd ed., M., 1971; Amelin A.G., Technology of sulfuric acid, 2nd ed., M., 1983; Vasiliev B.T., Otvagina M.I., Technology of sulfuric acid, M., 1985. Yu.V. Filatov.

Chemical encyclopedia. Volume 4 >>

Sulfuric acid (H2SO4) is one of the most corrosive and dangerous chemicals 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 oxidation of sulfur dioxide (SO2) by the contact method.

At a temperature of + 10.5 °C, sulfuric acid turns into a frozen 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 - the ability to remove water from the air. This process is accompanied by a massive release of heat.
2. H2SO4 is a strong acid.
3. Sulfuric acid is called monohydrate - it contains 1 mol of H2O (water) per 1 mol of SO3. Because of its impressive hygroscopic properties, it is used to extract moisture from gases.
4. Boiling point - 330 ° C. In this case, the acid is decomposed 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 must 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 dilute state, sulfuric acid is capable of oxidizing all metals that are in the series of voltages to hydrogen. An exception is made as the most resistant to oxidation. Dilute sulfuric acid reacts with salts, bases, amphoteric and basic oxides. Concentrated sulfuric acid is capable of oxidizing all metals in the series of voltages, and silver too.
7. Sulfuric acid forms two types of salts: acidic (hydrosulfates) and medium (sulfates)
8. H2SO4 enters into an active reaction with organic substances and non-metals, and it can turn some of them into coal.
9. Sulfuric anhydrite is perfectly soluble in H2SO4, and in this case 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 acid, and when it is added to water, a huge amount of heat is released. When preparing dilute solutions of H2SO4 from concentrated ones, it is necessary to add a heavier acid to water in a small stream, and not vice versa. This is done to avoid boiling water and splashing acid.

Concentrated and dilute sulfuric acids

Concentrated solutions of sulfuric acid include solutions from 40%, 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 able to react with brass and copper.

Getting sulfuric acid

The production of sulfuric acid on an industrial scale was launched in the 15th century, but at that time it was called "vitriol". 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.

The production of sulfuric acid is carried out industrially, and there are three of them:

1. contact method.
2. nitrous method
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:

• It turns out a product that satisfies 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 pyrites);
• sulfur;
• vanadium oxide (this substance causes the role of a catalyst);
• hydrogen sulfide;
• sulfides of various metals.

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

The production part is divided into several stages:

1. After crushing, pyrite is cleaned and sent to the furnace - where it is fired at temperatures up to 800 ° C. According to the principle of counterflow, air is supplied to 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 fire. During the roasting process, wastes appear in the form of iron oxide, which are removed and subsequently transferred to the enterprises of the metallurgical industry. During firing, water vapor, O2 and SO2 gases are released. 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 start of the reaction starts when the temperature reaches 420 °C, but it can be increased to 550 °C in order to increase efficiency. During the reaction, catalytic oxidation occurs and SO2 becomes SO3.
3. The essence of the third stage of production is as follows: the absorption of SO3 in the absorption tower, during which the oleum H2SO4 is formed. In this form, H2SO4 is poured into special containers (it does not react with steel) and is ready to meet the end user.

During 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 exhaust steam to generate additional electricity.

Nitrous process for the production of sulfuric acid

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

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

The conversion 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, the oxidation of sulfur dioxide is carried out using nitrogen oxides. Higher oxides of nitrogen (we are talking about nitrogen dioxide NO2, nitrogen trioxide NO3) in this process are reduced to nitric 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.
• Product quality is low.
• 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.
• The possibility of processing SO2 at 100%.
• Simplicity of hardware design.

Major Russian Sulfuric Acid Plants

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

Crimean Titan, the largest producer of titanium dioxide in Eastern Europe, operates in Armyansk, Crimea. In addition, the plant is engaged in the production of sulfuric acid, mineral fertilizers, iron sulphate, 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, Kirishinefteorgsintez Production Association, etc.

Sulfuric acid of high purity is produced by UCC Shchekinoazot, Component-Reaktiv.

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

Manufacturers 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 product of enrichment enterprises, its suppliers are the Norilsk and Talnakh enrichment plants.

The leading world positions 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 sulfuric acid

The world annually consumes about 200 million tons of H2SO4, from which a wide range of products is 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 scope of sulfuric acid is quite wide. The main uses of H2SO4 are as follows:

• Sulfuric acid is used in huge volumes for the production of mineral fertilizers, and it takes about 40% of the total tonnage. For this reason, plants producing H2SO4 are being built next to fertilizer plants. These are ammonium sulfate, superphosphate, etc. In their production, sulfuric acid is taken in its pure form (100% concentration). It will take 600 liters of H2SO4 to produce a ton of ammophos or superphosphate. These fertilizers are mostly used in agriculture.
• H2SO4 is used to make explosives.
• Purification 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 refining oil for the purification of hydrocarbons, this industry "takes" as much as 30% of the world's tonnage of H2SO4. In addition, the octane number of fuel is increased with sulfuric acid and wells are treated during oil production.
• in the metallurgical industry. Sulfuric acid is used in metallurgy to remove scale and rust from wire, sheet metal, as well as to reduce 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 manufacture of medicines.
• in the production of paints.
• in the chemical industry. H2SO4 is used in the production of detergents, ethyl detergent, insecticides, etc., and these processes are impossible without it.
• To obtain other known acids, organic and inorganic compounds used for industrial purposes.

Sulfuric acid salts and their uses

The most important salts of sulfuric acid are:

• 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 fluoroscopy of the stomach. 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 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 molds are made from it. In plastering work, alabaster is indispensable as a binder. Patients of trauma departments are given special fixing solid bandages - they are made on the basis of alabaster.
• Ferrous vitriol FeSO4 7H2O is used for the preparation of ink, impregnation of wood, and also in agricultural activities for the destruction of pests.
• Alum KCr(SO4)2 12H2O, KAl(SO4)2 12H2O, etc. are used in the production of paints and the leather industry (tanning).
• Many of you know copper sulfate CuSO4 5H2O 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 plants. It is also used to prepare some mineral paints. And in everyday life it is used to remove mold from the walls.
• Aluminum sulfate - it is used in the pulp and paper industry.

Sulfuric acid in dilute form is used as an electrolyte in lead-acid batteries. In addition, it is used to make detergents and fertilizers. But in most cases, it comes in the form of oleum - this is a solution of SO3 in H2SO4 (other oleum formulas can also be found).

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

The sphere of use of the “queen of acids” is truly large-scale, and it is difficult to tell about all the ways in which it is used in industry. It is also used as an emulsifier in the food industry, for water treatment, in the synthesis of explosives, and for many other purposes.

History of sulfuric acid

Who among us has never heard of blue vitriol? So, it was studied in antiquity, and in some works of the beginning of a new era, scientists discussed the origin of vitriol and their properties. Vitriol was studied by the Greek physician Dioscorides, the Roman explorer 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 from Panopolis.

The first method of obtaining sulfuric acid is the process of heating potassium alum, and there is information about this in the alchemical literature of the XIII 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 they began to engage in the chemical synthesis of sulfuric acid purposefully. The process was as follows: alchemists treated a mixture of sulfur and antimony (III) sulfide Sb2S3 by heating with nitric acid.

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

In the 17th century, Johann Glauber obtained sulfuric acid by burning 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, an oily liquid was obtained. It was vitriol oil, and this name for sulfuric acid exists to this day.

The pharmacist from London, 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 a few tens of kilograms. The scope of use was narrow: for alchemical experiments, purification of precious metals and in the pharmaceutical business. Concentrated sulfuric acid was used in small quantities in the manufacture of special matches that contained bertolet salt.

In Russia only in the 17th century vitriol appeared.

In Birmingham, England, John Roebuck adapted the above method for producing sulfuric acid in 1746 and launched production. At the same time, he used strong large lead-lined chambers, which were cheaper than glass containers.

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

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

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

Initially, this was done using nitrogen oxides, and then platinum was used as a catalyst. These two methods of oxidizing sulfur dioxide have further improved. The oxidation of sulfur dioxide on platinum and other catalysts became known as the contact method. And the oxidation of this gas with nitrogen oxides was called the nitrous method for producing sulfuric acid.

It was not until 1831 that the British acetic acid dealer Peregrine Philips patented an economical process for the production of sulfur oxide (VI) and concentrated sulfuric acid, and it is he who is today known to the world as a contact method for obtaining it.

The production of superphosphate 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.

Transportation of sulfuric acid is a labor-intensive and responsible undertaking.

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

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

Transportation by road is carried out according to the following rules:

1. For transportation, special containers are made of a special steel alloy that does not react with sulfuric acid or titanium. Such containers do not oxidize. 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 taken, in which the required temperature is maintained to preserve the chemical properties of the acid.
3. If ordinary acid is being 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. Transportation of dangerous goods can only be carried out by drivers who have an ADR certificate in their hands.
6. Travel time has no restrictions, since during transportation it is necessary to 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 by direct contact with the skin, but by inhalation of its vapors, when sulfur dioxide is released. The hazard applies to:

• respiratory system;
• Integuments;
• Mucous membranes.

Intoxication of the body can be enhanced by arsenic, which is often part of sulfuric acid.

Important! As you know, when acid comes into contact with the skin, severe burns occur. No less dangerous is poisoning with sulfuric acid vapors. 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, which 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 care is not provided in a timely manner.

Important! For an adult, the lethal dose of sulfuric acid is only 0.18 cm per 1 liter.

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

Mass poisoning with sulfuric acid vapor can occur due to technical problems in production or negligence, and a massive release into the atmosphere occurs. To prevent such situations, special services are working, the task of which is to control the functioning of production where hazardous acid is used.

What are the symptoms of sulfuric acid intoxication?

If the acid was ingested:

• Pain in the region of the digestive organs.
• Nausea and vomiting.
• Violation of the stool, as a result of severe intestinal disorders.
• Strong secretion of saliva.
• Due to the toxic effects on the kidneys, the urine becomes reddish.
• Swelling of the larynx and throat. There are wheezing, hoarseness. This can lead to death 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 in pairs, the following picture is observed:

• Burn 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, 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 damage by sulfuric acid

Proceed as follows when in contact with sulfuric acid:

• Call an ambulance first. If the liquid got inside, then do a gastric lavage 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 the eyes, rinse them with running water, and then drip with a solution of dicaine and novocaine.
• If acid gets on the skin, the burned area should be washed well under running water and bandaged with soda. Rinse for about 10-15 minutes.
• In case of vapor poisoning, you need to go out into fresh air, and also rinse the affected mucous membranes with water as far as possible.

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 an infection in the affected area, a course of antibiotic therapy is selected for the patient.

In gastric bleeding, plasma is injected or blood is transfused. The source of bleeding can be removed surgically.

1. Sulfuric acid in its pure 100% form is found in nature. For example, in Italy, Sicily in the Dead Sea, you can see a unique phenomenon - sulfuric acid seeps right from the bottom! And 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 change.
3. Sulfuric acid is an active water absorber, so it is used as a gas dryer. In the old days, in order to prevent windows from fogging up in the rooms, this acid was poured into jars and placed between the panes of window openings.
4. Sulfuric acid is the main cause of acid rain. The main cause of acid rain is air pollution with sulfur dioxide, and when dissolved in water, it forms sulfuric acid. In turn, sulfur dioxide is emitted when fossil fuels are burned. In the acid rains studied in recent years, the content of nitric acid has increased. The reason for this phenomenon is the reduction of 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 of sulfuric acid entering the flask with sugar, the mixture darkens. After a few seconds, the substance turns black. The most interesting thing happens next. The mass begins to grow rapidly and climb out of the flask. At the output, we get a proud substance, similar to porous charcoal, exceeding the original 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 made from cellulose. When acid enters, cellulose molecules instantly break down 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 a flask with concentrated acid. In the first second, smoke is released, after which the metal instantly flares up, lights up and explodes, cutting into pieces.

In the next experiment, when sulfuric acid hits a match, it flares up. In the second part of the experiment, aluminum foil is immersed with acetone and a match inside. There is an instantaneous heating of the foil 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. Soda instantly turns yellow. The reaction proceeds with rapid boiling and an increase in volume.

We categorically do not advise to carry 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 highly toxic and can cause damage to the respiratory tract and poison the body. In addition, such experiments are carried out in personal protective equipment for the skin and respiratory organs. Take care of yourself!

Sulfuric acid (H₂SO₄) is one of the strongest dibasic acids.

In terms of physical properties, sulfuric acid looks like a thick, odorless, transparent oily liquid. Depending on the concentration, sulfuric acid has many different properties and applications:

• metal processing;
• ore processing;
• production of mineral fertilizers;
• chemical synthesis.

History of the discovery of sulfuric acid

Contact sulfuric acid has a concentration of 92 to 94 percent:

2SO₂ + O₂ = 2SO₂;

H₂O + SO₃ = H₂SO₄.

Physical and physico-chemical properties of sulfuric acid

H₂SO₄ is miscible with water and SO₃ in all proportions.

In aqueous solutions H₂SO₄ forms hydrates of the type H₂SO₄ nH₂O

The boiling point of sulfuric acid depends on the degree of concentration of the solution and reaches a maximum at a concentration of more than 98 percent.

Caustic compound oleum is a solution of SO₃ in sulfuric acid.

With an increase in the concentration of sulfur trioxide in oleum, the boiling point decreases.

Chemical properties of sulfuric acid

When heated, concentrated sulfuric acid is the strongest oxidizing agent that can oxidize many metals. The only exceptions are some metals:

• gold (Au);
• platinum (Pt);
• iridium (Ir);
• rhodium (Rh);
• tantalum (Ta).

By oxidizing metals, concentrated sulfuric acid can be reduced to H₂S, S and SO₂.

Active metal:

8Al + 15H₂SO₄(conc.) → 4Al₂(SO₄)₃ + 12H₂O + 3H₂S

Medium activity metal:

2Cr + 4 H₂SO₄(conc.) → Cr₂(SO₄)₃ + 4 H₂O + S

Inactive metal:

2Bi + 6H₂SO₄(conc.) → Bi₂(SO₄)₃ + 6H₂O + 3SO₂

Iron does not react with cold concentrated sulfuric acid, because it is covered with an oxide film. This process is called passivation.

Reaction of sulfuric acid and H₂O

When H₂SO₄ is mixed with water, an exothermic process occurs: such a large amount of heat is released that the solution may even boil. When conducting chemical experiments, one should always add sulfuric acid little by little to water, and not vice versa.

Sulfuric acid is a strong dehydrating agent. Concentrated sulfuric acid displaces water from various compounds. It is often used as a desiccant.

reaction of sulfuric acid and sugar

The greed of sulfuric acid for water can be demonstrated in the classic experiment - mixing concentrated H₂SO₄ and which is an organic compound (carbohydrate). To extract water from a substance, sulfuric acid destroys the molecules.

To conduct the experiment, add a few drops of water to the sugar and mix. Then carefully pour in sulfuric acid. After a short period of time, a violent reaction can be observed with the formation of coal and the release of sulfur and.

Sulfuric acid and sugar cube:

Remember that working with sulfuric acid is very dangerous. Sulfuric acid is a caustic substance that instantly leaves severe burns on the skin.

you will find safe sugar experiments you can do at home.

Reaction of sulfuric acid and zinc

This reaction is quite popular and is one of the most common laboratory methods for producing hydrogen. If zinc granules are added to dilute sulfuric acid, the metal will dissolve with the release of gas:

Zn + H₂SO₄ → ZnSO₄ + H₂.

Dilute sulfuric acid reacts with metals that are to the left of hydrogen in the activity series:

Me + H₂SO₄(dec.) → salt + H₂

Reaction of sulfuric acid with barium ions

A qualitative reaction to and its salts is a reaction with barium ions. It is widely used in quantitative analysis, in particular gravimetry:

H₂SO₄ + BaCl₂ → BaSO₄ + 2HCl

ZnSO₄ + BaCl₂ → BaSO₄ + ZnCl₂

Attention! Do not try to repeat these experiments yourself!