O3 chemistry what. Methods for producing ozone. Ozone (O3) is a triatomic modification of oxygen (O2). How does ozone affect the human body?

To the question about the chemical properties of ozone asked by the author Part.wholesale. the best answer is Chemical properties
The O3 molecule is unstable and, at sufficient concentrations in the air under normal conditions, spontaneously turns into O2 within a few tens of minutes, releasing heat.
Ozone is a powerful oxidizing agent, much more reactive than diatomic oxygen. Oxidizes almost all metals (except gold, platinum and iridium) to their highest oxidation states. Oxidizes many non-metals.
2 Cu2+(aq) + 2 H3O+(aq) + O3(g) → 2 Cu3+(aq) + 3 H2O(l) + O2(g)
Ozone increases the degree of oxidation of oxides:
NO + O3 → NO2 + O2
This reaction is accompanied by chemiluminescence. Nitrogen dioxide can be oxidized to nitrogen trioxide:
NO2 + O3 → NO3 + O2
with the formation of nitric anhydride N2O5:
NO2 + NO3 → N2O5
Ozone reacts with carbon at normal temperature to form carbon dioxide:
C + 2 O3 → CO2 + 2 O2
Ozone does not react with ammonium salts, but reacts with ammonia to form ammonium nitrate:
2 NH3 + 4 O3 → NH4NO3 + 4 O2 + H2O
Ozone reacts with sulfides to form sulfates:
PbS + 4 O3 → PbSO4 + 4 O2
Using ozone, you can obtain sulfuric acid from both elemental sulfur and sulfur dioxide:
S + H2O + O3 → H2SO4
3 SO2 + 3 H2O + O3 → 3 H2SO4
All three oxygen atoms in ozone can react individually in the reaction of tin chloride with hydrochloric acid and ozone:
3 SnCl2 + 6 HCl + O3 → 3 SnCl4 + 3 H2O
In the gas phase, ozone reacts with hydrogen sulfide to form sulfur dioxide:
H2S + O3 → SO2 + H2O
In an aqueous solution, two competing reactions with hydrogen sulfide take place, one with the formation of elemental sulfur, the other with the formation of sulfuric acid:
H2S + O3 → S + O2 + H2O
3 H2S + 4 O3 → 3 H2SO4
By treating a solution of iodine in cold anhydrous perchloric acid with ozone, iodine (III) perchlorate can be obtained:
I2 + 6 HClO4 + O3 → 2 I(ClO4)3 + 3 H2O
Solid nitrile perchlorate can be obtained by the reaction of gaseous NO2, ClO2 and O3:
2 NO2 + 2 ClO2 + 2 O3 → 2 NO2ClO4 + O2
Ozone can participate in combustion reactions, with combustion temperatures higher than with diatomic oxygen:
3 C4N2 + 4 O3 → 12 CO + 3 N2
Ozone can react at low temperatures. At 77 K (-196 °C), atomic hydrogen reacts with ozone to form a superoxide radical with dimerization of the latter:
H + O3 → HO2 + O
2 HO2 → H2O4
Ozone can form ozonides containing the O3- anion. These compounds are explosive and can be stored at low temperatures. Ozonides of all alkali metals are known. KO3, RbO3, and CsO3 can be prepared from the corresponding superoxides:
KO2 + O3 → KO3 + O2
Potassium ozonide can also be obtained in another way from potassium hydroxide:
2 KOH + 5 O3 → 2 KO3 + 5 O2 + H2O
NaO3 and LiO3 can be prepared by reacting CsO3 in liquid ammonia NH3 with ion exchange resins containing Na+ or Li+ ions:
CsO3 + Na+ → Cs+ + NaO3
Treatment of a solution of calcium in ammonia with ozone results in the formation of ammonium ozonide, not calcium:
3 Ca + 10 NH3 + 6 O3 → Ca 6NH3 + Ca(OH)2 + Ca(NO3)2 + 2 NH4O3 + 2 O2 + H2
Ozone can be used to remove manganese from water to form a precipitate that can be removed by filtration:
2 Mn2+ + 2 O3 + 4 H2O → 2 MnO(OH)2 (s) + 2 O2 + 4 H+
Ozone converts cyanides into many times less toxic cyanates:
CN- + O3 → CNO- + O2
Ozone can completely decompose urea:
(NH2)2CO + O3 → N2 + CO2 + 2 H2O

GENERAL INFORMATION.

Ozone - O3, an allotropic form of oxygen, is a powerful oxidizer of chemicals and other pollutants that are destroyed on contact. Unlike the oxygen molecule, the ozone molecule consists of three atoms and has longer bonds between the oxygen atoms. In terms of its reactivity, ozone ranks second, second only to fluorine.

History of discovery
In 1785, the Dutch physicist Van Ma-rum, conducting experiments with electricity, drew attention to the smell during the formation of sparks in an electric machine and to the oxidizing properties of air after electric sparks were passed through it.
In 1840, the German scientist Sheinbein, while hydrolyzing water, tried to split it into oxygen and hydrogen using an electric arc. And then he discovered that a new gas, hitherto unknown to science, had formed with a specific odor. The name “ozone” was assigned to the gas by Sheinbein because of its characteristic odor and comes from the Greek word “ozien”, which means “to smell”.
On September 22, 1896, inventor N. Tesla patented the first ozone generator.

Physical properties of ozone.
Ozone can exist in all three states of aggregation. Under normal conditions, ozone is a bluish gas. The boiling point of ozone is 1120C, and the melting point is 1920C.
Due to its chemical activity, ozone has a very low maximum permissible concentration in the air (comparable to the maximum permissible concentration of chemical warfare agents) 5·10-8% or 0.1 mg/m3, which is 10 times the olfactory threshold for humans.

Chemical properties of ozone.
First of all, two main properties of ozone should be noted:

Ozone, unlike atomic oxygen, is a relatively stable compound. It decomposes spontaneously at high concentrations, and the higher the concentration, the faster the rate of decomposition reaction. At ozone concentrations of 12-15%, ozone can decompose explosively. It should also be noted that the process of ozone decomposition accelerates with increasing temperature, and the decomposition reaction itself 2O3>3O2 + 68 kcal is exothermic and is accompanied by the release of a large amount of heat.

O3 -> O + O 2
O3 + O -> 2 O2
O2 + E- -> O2-

Ozone is one of the strongest natural oxidizing agents. The oxidation potential of ozone is 2.07 V (for comparison, fluorine has 2.4 V, and chlorine has 1.7 V).

Ozone oxidizes all metals except gold and the platinum group, oxidizes sulfur and nitrogen oxides, and oxidizes ammonia to form ammonium nitrite.
Ozone actively reacts with aromatic compounds, destroying the aromatic nucleus. In particular, ozone reacts with phenol to destroy the nucleus. Ozone actively interacts with saturated hydrocarbons with the destruction of double carbon bonds.
The interaction of ozone with organic compounds is widely used in the chemical industry and related industries. The reactions of ozone with aromatic compounds formed the basis of deodorization technologies for various environments, premises and wastewater.

Biological properties of ozone.
Despite a large number of studies, the mechanism is not well understood. It is known that at high concentrations of ozone, damage to the respiratory tract, lungs and mucous membranes is observed. Long-term exposure to ozone leads to the development of chronic diseases of the lungs and upper respiratory tract.
Exposure to small doses of ozone has a preventive and therapeutic effect and is beginning to be actively used in medicine - primarily for dermatology and cosmetology.
In addition to its great ability to destroy bacteria, ozone is highly effective in destroying spores, cysts (dense membranes that form around unicellular organisms, for example, flagellates and rhizomes, during their reproduction, as well as in unfavorable conditions for them) and many other pathogenic microbes.

Technological applications of ozone
Over the past 20 years, the applications of ozone have expanded significantly and new developments are underway around the world. Such rapid development of technologies using ozone is facilitated by its environmental cleanliness. Unlike other oxidizing agents, ozone decomposes during reactions into molecular and atomic oxygen and saturated oxides. All these products, as a rule, do not pollute the environment and do not lead to the formation of carcinogenic substances, such as, for example, during oxidation with chlorine or fluorine.

Water:
In 1857, with the help of the “perfect magnetic induction tube” created by Werner von Siemens, the first technical ozone installation was built. In 1901, Siemens built the first hydroelectric power station with an ozone generator in Wiesband.
Historically, the use of ozone began with drinking water treatment plants, when the first pilot plant was tested in the city of San Maur (France) in 1898. Already in 1907, the first water ozonation plant was built in the city of Bon Voyage (France) for the needs of the city of Nice. In 1911, an ozonation station for drinking water was put into operation in St. Petersburg.
Currently, 95% of drinking water in Europe is treated with ozone. In the USA, the process of converting from chlorination to ozonation is underway. There are several large stations in Russia (in Moscow, Nizhny Novgorod and other cities).

Air:
The use of ozone in water purification systems has been proven to be highly effective, but equally effective and proven safe air purification systems have not yet been created. Ozonation is considered a non-chemical cleaning method and is therefore popular among the population. However, the chronic effects of micro-concentrations of ozone on the human body have not been sufficiently studied.
With a very low concentration of ozone, the air in the room feels pleasant and fresh, and unpleasant odors are much less noticeable. Contrary to the popular belief about the beneficial effects of this gas, which is attributed in some brochures to ozone-rich forest air, in reality ozone, even when highly diluted, is a very toxic and dangerous irritant gas. Even small concentrations of ozone can have an irritating effect on mucous membranes and cause disorders of the central nervous system, which leads to bronchitis and headaches.

Medical uses of ozone
In 1873, Focke observed the destruction of microorganisms under the influence of ozone, and this unique property of ozone attracted the attention of doctors.
The history of the use of ozone for medical purposes dates back to 1885, when Charlie Kenworth first published his report in the Florida Medical Association, USA. Brief information about the use of ozone in medicine has been found before this date.
In 1911, M. Eberhart used ozone in the treatment of tuberculosis, anemia, pneumonia, diabetes and other diseases. A. Wolf (1916) during the First World War used an oxygen-ozone mixture in the wounded for complex fractures, phlegmon, abscesses, and purulent wounds. N. Kleinmann (1921) used ozone for the general treatment of “body cavities”. In the 30s 20th century E.A. Fish, a dentist, begins ozone treatment in practice.
In the application for the invention of the first laboratory device, Fish proposed the term "CYTOZON", which is still listed on ozone generators used in dental practice today. Joachim Hänzler (1908-1981) created the first medical ozone generator, which allowed precise dosing of the ozone-oxygen mixture, and thus made it possible to widely use ozone therapy.
R. Auborg (1936) revealed the effect of scarring of colon ulcers under the influence of ozone and drew attention to the nature of its general effect on the body. Work on studying the therapeutic effects of ozone during the Second World War actively continued in Germany; the Germans successfully used ozone for local treatment of wounds and burns. However, after the war, research was interrupted for almost two decades, due to the advent of antibiotics and the lack of reliable, compact ozone generators and ozone-resistant materials. Extensive and systematic research in the field of ozone therapy began in the mid-70s, when ozone-resistant polymer materials and easy-to-use ozonation units appeared in everyday medical practice.
Research in vitro , that is, under ideal laboratory conditions, they showed that when interacting with the cells of the body, ozone oxidizes fats and forms peroxides - substances that are harmful to all known viruses, bacteria and fungi. In terms of its action, ozone can be compared to antibiotics, with the difference that it does not damage the liver and kidneys and has no side effects. But unfortunately, in vivo - in real conditions everything is much more complicated.
Ozone therapy was very popular at one time - many considered ozone almost a panacea for all ailments. But a detailed study of the effects of ozone showed that along with the sick, ozone also affects healthy cells of the skin and lungs. As a result, unexpected and unpredictable mutations begin in living cells. Ozone therapy never took root in Europe, and in the USA and Canada the official medical use of ozone is not legalized, with the exception of alternative medicine.
In Russia, unfortunately, official medicine has not abandoned such a dangerous and insufficiently proven method of therapy. Currently, air ozonizers and ozonizer units are widely used. Small ozone generators are used in the presence of people.

OPERATING PRINCIPLE.
Ozone is formed from oxygen. There are several ways to produce ozone, the most common of which are: electrolytic, photochemical and electrosynthesis in gas discharge plasma. In order to avoid unwanted oxides, it is preferable to obtain ozone from pure medical oxygen using electrosynthesis. The concentration of the resulting ozone-oxygen mixture in such devices is easy to vary - either by setting a certain power of the electrical discharge, or by regulating the flow of incoming oxygen (the faster the oxygen passes through the ozonator, the less ozone is formed).

Electrolytic The ozone synthesis method is carried out in special electrolytic cells. Solutions of various acids and their salts (H2SO4, HClO4, NaClO4, KClO4) are used as electrolytes. The formation of ozone occurs due to the decomposition of water and the formation of atomic oxygen, which, when added to an oxygen molecule, forms ozone and a hydrogen molecule. This method produces concentrated ozone, but it is very energy intensive and is therefore not widely used.
Photochemical The method of producing ozone is the most common method in nature. Ozone is formed when an oxygen molecule dissociates under the influence of short-wave UV radiation. This method does not produce high concentration ozone. Devices based on this method have become widespread for laboratory purposes, in medicine and the food industry.
Electrosynthesis ozone is most widespread. This method combines the ability to obtain high concentrations of ozone with high productivity and relatively low energy costs.
As a result of numerous studies on the use of various types of gas discharge for ozone electrosynthesis, devices using three forms of discharge have become widespread:

1. Barrier discharge - the most widely used, is a large set of pulsed microdischarges in a gas gap 1-3 mm long between two electrodes separated by one or two dielectric barriers when the electrodes are powered with alternating high voltage with a frequency of 50 Hz to several kilohertz. The productivity of one installation can range from grams to 150 kg of ozone per hour.
2. Surface discharge - close in shape to a barrier discharge, which has become widespread in the last decade due to its simplicity and reliability. It is also a set of microdischarges developing along the surface of a solid dielectric when the electrodes are powered with alternating voltage with a frequency of 50 Hz to 15-40 kHz.
3. Pulse discharge - as a rule, a streamer corona discharge that occurs in the gap between two electrodes when the electrodes are powered with a pulse voltage lasting from hundreds of nanoseconds to several microseconds.

• Effective in cleaning indoor air.
• Do not produce harmful by-products.
• Facilitates conditions for allergy sufferers, asthmatics, etc.

In 1997, ozonizer manufacturing companies Living Air Corporation, Alpine Industries Inc. (now “Ecoguest”), Quantum Electronics Corp. and others who violated the US FTC order were administratively punished by the courts, including a ban on further activities of some of them in the United States. At the same time, private entrepreneurs who sold ozone generators with recommendations for using them in rooms with people received prison sentences ranging from 1 to 6 years.
Currently, some of these Western companies are successfully developing active sales of their products in Russia.

Disadvantages of ozonizers:
Any sterilization system using ozone requires careful safety monitoring, testing of ozone concentration constants with gas analyzers, and emergency management of excessive ozone concentrations.
The ozonizer is not designed to work in:

• environment saturated with electrically conductive dust and water vapor,
• places containing active gases and vapors that destroy metal,
• places with relative humidity above 95%,
• in explosion and fire hazardous areas.

Application of ozonizers for indoor air sterilization:

• lengthens the time of the sterilization process,
• increases toxicity and oxidation of the air,
• leads to a danger of explosion,
• The return of people to a disinfected room is possible only after the ozone has completely decomposed.

SUMMARY.
Ozonation is highly effective for sterilizing surfaces and indoor air, but there is no effect of purifying the air from mechanical impurities. The impossibility of using the method in the presence of people and the need to carry out disinfection in a sealed room seriously limits the scope of its professional application.

Ozone is a blue gas with a characteristic odor and a very strong oxidizing agent. The molecular formula of ozone is O 3. It is heavier than oxygen and our usual air.

It is difficult to find a person who would not know about the existence of ozone holes in the Earth’s stratosphere, depriving us of protection from excess ultraviolet radiation from the Sun, which is destructive for all living things. Against the backdrop of this global problem, the impact on our health would seem completely innocent. other ozone, located in the surface air that we breathe. People pay attention to air pollution from industrial emissions and car exhaust, but few people know how dangerous ground-level ozone for the human body.

Ground-level ozone is a secondary pollutant. It is not emitted into the atmospheric air from sources, but is formed as a result of photochemical reactions of precursors - volatile organic compounds, nitrogen oxides and carbon monoxide, the source of emissions of which are motor vehicles, boiler houses and industrial enterprises. Ozone is one of the main components of photochemical smog, which causes eye diseases, headaches, coughs, pulmonary diseases, etc. Asthmatics and children are most susceptible to negative effects.

In high concentrations, ozone is a powerful poison, surpassing cyanide in its harmful properties! The high oxidizing ability of ozone and the formation of free oxygen radicals in many reactions with its participation determine its highest toxicity. Exposure of the body to ozone can lead to premature death. That is why ozone in the Russian Federation is classified as the first “EXTREMELY DANGEROUS SUBSTANCES”, the highest class of hazardous substances!

What is the danger and harm of ozone to humans?

Because ozone is particularly toxic, the World Health Organization has included it in its list of the top five pollutants that need to be monitored when determining air quality.

Ozone negatively affects humans, having an irritating, carcinogenic, mutagenic, and genotoxic effect. It can enter the body through breathing. High concentrations of ozone can cause changes in lung function, cause inflammatory processes in the respiratory tract and increased reactivity of the body when using bronchoconstrictors. The World Health Organization has classified ozone as a non-threshold substance, that is, any concentration in the air of this gas, a strong carcinogen, is dangerous to humans. Ozone also affects vegetation, as it is a very phytotoxic compound that causes damage to the foliage of agricultural and fruit crops, coniferous and deciduous tree species. The toxicity of ozone increases greatly in the presence of nitrogen oxides in the air: together they act 20 times more powerfully than separately.

Study of the influence of ozone on humans in the USA and Europe

The higher the concentration of ozone in the surface atmosphere, the stronger people experience its negative impact on their health. This occurs most often during the summer months and as ozone concentrations in the lower atmosphere increase, the number of people hospitalized with respiratory problems increases. In the US, scientists have determined that one in three Americans are more sensitive to ozone and this group has a higher risk of harming their health due to ozone exposure. People from this risk group should pay special attention to information about the ozone content in the atmosphere of their places of residence. This information is provided locally by the EPA (Environmental Protection Agency) in conjunction with the US government. Based on this information, Americans should make decisions related to risks to their health. Scientists have studied the effects of ozone on human health and have now found the following:

• ozone causes irritation of the respiratory system, cough, heaviness in the chest; these effects can last several hours and progress to a painful phase;
• ozone reduces pulmonary function; if you work outdoors, you will notice how your breathing becomes more frequent and less deep; decreased lung function can become an occupational disease for athletes who train outdoors;
• ozone promotes the development of asthma and increases the number of attacks of this disease;
• ozone causes allergies to the most common substances - dust, cockroaches, pollen, pets;
• ozone damages lung tissue; repeated exposure to ozone causes changes in lung tissue and can lead to long-term health problems;
• ozone aggravates bronchitis and emphysema;
• ozone significantly reduces immunity to infection;
• The effects of ozone on children are especially dangerous; their lungs can be severely damaged by ozone exposure and this is negative
• will affect their development;
• Scientists believe that ozone has other harmful effects on human health.

Four groups of people are especially sensitive to ozone during their active outdoor lifestyle:

• CHILDREN. Active children have a very high risk of negative ozone exposure. When breathing deeply, ozone penetrates into the areas of the lungs that are most sensitive to ozone.

• ADULTS leading an active outdoor lifestyle.

• PEOPLE WITH RESPIRATORY DISEASES may be harmed by low concentrations of ozone.

• PEOPLE WITH UNUSUAL SENSITIVITY TO OZONE. Scientists cannot explain why some healthy people are more sensitive to ozone than others. They experience greater negative health effects from ozone.

• ELDERLY PEOPLE AND PEOPLE WITH HEART DISEASE are at higher risk from ozone exposure than others.

Scientists believe that ozone negatively affects health even if a person does not feel any signs of its effects.

Exposure to 3 mg/l ozone kills small animals within 5 minutes. 50% of white mice die after 2 hours at an ozone concentration in the air of 0.046 mg/l, after 4 hours at 0.00053 – 0.001 mg/l.

After 18 o'clock Inhalation of O3 at a concentration of 0.0012 mg/l causes pulmonary edema in rats. Half of the guinea pigs died after 3 hours of inhaling O3 at a concentration of 0.01 mg/l, rabbits 0.0074 mg/l, cats 0.007 mg/l. In addition to pulmonary edema, the animals observed inflammation of the liver and kidneys, a decrease in lipoids in the adrenal cortex, and mobilization of macrophages.

In Europe, considerable attention is also paid to the problem of this toxic gas. Monitoring of ground-level ozone in the EU countries is carried out at a network of monitoring stations. In 2002, there were more than 1,700 of them. And in Germany, for example, the most visited site on the Internet is a site that informs about the ozone content in the ground-level atmosphere and about ways to protect the population from its effects.

Ozone in the atmosphere

Ten percent of ozone is found in the lower layers of the atmosphere (troposphere), between the earth's surface and an altitude of 10 to 16 kilometers. Ninety percent of ozone is found in the stratosphere, from the upper troposphere to an altitude of 50 kilometers.

Stratospheric ozone- what scientists call the ozone layer - has uneven thickness above the Earth. The ozone layer over Antarctica is thinnest due to unique atmospheric conditions that promote concentrations of ozone-depleting chemicals.

Atmospheric ozone plays an important role for all life on the planet. By forming the ozone layer in the stratosphere, it protects plants and animals from harsh ultraviolet radiation. Therefore, the problem of ozone hole formation is of particular importance. However, tropospheric ozone is a pollutant that can threaten human and animal health and damage plants.

In nature, ozone is intensively formed during thunderstorms. And indeed it is. But there is another extremely important source of the formation of this amazing gas. It is generated by sunlight, which converts oxygen into ozone in the stratosphere. Thanks to the continuous formation of stratospheric ozone, all life on earth is under constant protection from the harmful effects of hard ultraviolet radiation.

Depending on its location in the atmosphere, ozone can either help or harm life on Earth. In the troposphere, ozone acts primarily as a pollutant in smog, which harms the respiratory system of animals and slows plant growth. The amount of naturally occurring ozone in the troposphere is too small to pose a threat to human health or the environment. Most of the harmful ozone that makes up smog is formed when sunlight reacts with hydrocarbons and nitrogen oxides, byproducts of cars and fossil fuel power plants.

Ozone in everyday life

The use of ozone is due to its properties as a strong oxidizing agent:

Ozone is used for sterilization of medical products, in the production of many substances in laboratory and industrial practice, for bleaching paper, and purifying oils.

Ozone also has a strong disinfecting effect. Therefore, it is widely used to purify water and air from microorganisms (ozonation), to disinfect premises and clothing, and to ozonate infusion solutions used in medicine, both for intravenous and contact use.

Ozone therapy - benefit or harm?

According to ozone therapists, human health improves significantly when treated with ozone (externally, orally, intravenously and extracorporeally), but not a single objective clinical study has confirmed any significant therapeutic effect. Moreover, when using ozone as a medicine (especially when directly affecting the patient’s blood), the proven risk of its mutagenic, carcinogenic and toxic effects outweighs any theoretically possible positive effects, therefore, in almost all developed countries, ozone therapy is not recognized as a medicinal method, but its use in private clinics it is possible only with the informed consent of the patient.

Household ozonizers - harm or benefit?

Many people believe that ozone is beneficial to our environment, and it will get rid of harmful bacteria and purify the air in our rooms. But in everything good we must look for the golden mean. Ozonation must be used with extreme caution. Ozone is beneficial in certain doses, but excessive use of ozone can be harmful to living beings. If there is as much ozone in the room as required by standards, then breathing becomes easier, the lungs are cleansed, and the air becomes free of harmful germs and microorganisms. But if the concentration of ozone in the air exceeds, breathing becomes difficult, coughing and dizziness begin.

Let us remind you once again: ozone in the Russian Federation is classified as the first, highest class of hazardous substances.

In high concentrations, ozone burns mucous membranes, has a destructive effect on the protein structure of the human body, the circulatory and central nervous systems, causes headaches and chest pains, respiratory disorders, and can also cause exacerbation of asthma and a general weakening of lung function. Once in the body, it has a general toxic and carcinogenic effect on the body, causing general malaise with headache, nausea, and irritating cough.

Standards for maximum ozone concentration:

• maximum single maximum permissible concentration (MPC m.r.) in the atmospheric air of populated areas 0.16 mg/m³
• average daily maximum permissible concentration (MPC s.s.) in the atmospheric air of populated areas 0.03 mg/m³
• maximum permissible concentration (MPC) in the air of the working area 0.1 mg/m³

The smell of ozone is detected by humans in concentrations of 0.01-0.02 mg/m3, which is 5-10 times less than the maximum permissible concentration, so the appearance of a faint smell of ozone in a room is not an alarming signal. To ensure reliable control of ozone content in a room, it is necessary to invite specialists, conduct air tests and, if the maximum concentration limit is exceeded, take timely measures to reduce it to a safe level.

Have you ever noticed how pleasant it is to breathe after rain? This refreshing air provides ozone in the atmosphere, which appears after rain. What is this substance, what are its functions, formula, and is it really useful for the human body? Let's figure it out.

What is ozone?

Anyone who attended high school knows that an oxygen molecule is made up of two atoms of the chemical element oxygen. However, this element is capable of forming another chemical compound - ozone. This name is given to a substance that is usually found in the form of a gas (although it can exist in all three states of aggregation).

The molecule of this substance is quite similar to oxygen (O 2), but it consists not of two, but of three atoms - O 3.

History of the discovery of ozone

The man who first synthesized ozone was the Dutch physicist Martin Van Marum.

It was he who, in 1785, conducted an experiment by passing an electric discharge through the air. The resulting gas not only acquired a specific odor, but also a bluish tint. In addition, the new substance turned out to be a stronger oxidizing agent than ordinary oxygen. Thus, having examined its effect on mercury, Van Marum discovered that the metal slightly changed its physical properties, which did not happen to it under the influence of oxygen.

Despite his discovery, the Dutch physicist did not believe that ozone was a special substance. Only 50 years after Van Marum’s discovery, the German scientist Christian Friedrich Schönbein became seriously interested in ozone. It was thanks to him that this substance received its name - ozone (in honor of the Greek word meaning “to smell”), and was also more closely studied and described.

Ozone: physical properties

This substance has a number of properties. The first of these is the ability of ozone, like water, to exist in three states of aggregation.

The normal state in which ozone exists is a bluish gas (it is what colors the skies azure) with a noticeable metallic aroma. The density of such gas is 2.1445 g/dm³.

As the temperature decreases, ozone molecules form a blue-violet liquid with a density of 1.59 g/cm³ (at a temperature of -188 °C). Liquid O 3 boils at -111.8 °C.

While in a solid state, ozone darkens, becoming almost black with a distinct violet-blue tint. Its density is 1.73 g/cm 3 (at −195.7 °C). The temperature at which solid ozone begins to melt is −197.2 °C.

The molecular weight of O 3 is 48 daltons.

At a temperature of 0 °C, ozone dissolves perfectly in water, ten times faster than oxygen. The presence of impurities in water can further speed up this reaction.

In addition to water, ozone dissolves in freon, which facilitates its transportation.

Among other substances in which O3 is easy to dissolve (in a liquid aggregate state) are argon, nitrogen, fluorine, methane, carbon dioxide, and carbon tetrachloride.

It also mixes well with liquid oxygen (at temperatures from 93 K).

Chemical properties of ozone

The O3 molecule is quite unstable. For this reason, in its normal state it exists for 10-40 minutes, after which it decomposes, producing a small amount of heat and oxygen O 2. This reaction can occur much faster if the catalysts are an increase in ambient temperature or a decrease in atmospheric pressure. Ozone decomposition is also facilitated by its contact with metals (except gold, platinum and iridium), oxides or substances of organic origin.

Interaction with nitric acid stops the decomposition of O 3. This is also facilitated by storing the substance at a temperature of −78 °C.

The main chemical property of ozone is its oxidizability. One of the oxidation products is always oxygen.

Under different conditions, O 3 is able to interact with almost all substances and chemical elements, reducing their toxicity by turning them into less dangerous ones. For example, cyanides are oxidized to cyanates, which are much safer for biological organisms.

How do they get it?

Most often, to obtain O3, oxygen is exposed to electric current. To separate the resulting mixture of oxygen and ozone, they use the property of the latter to liquefy better than O2.

In chemical laboratories, O3 is sometimes produced by reacting a cooled sulfuric acid concentrate with barium peroxide.

In medical institutions that use O3 to improve the health of patients, this substance is obtained by irradiating O2 with ultraviolet light (by the way, this substance is formed in the same way in the Earth’s atmosphere under the influence of sunlight).

Use of O3 in medicine and industry

The simple structure of ozone and the availability of the starting material for its extraction contribute to the active use of this substance in industry.

Being a strong oxidizing agent, it can disinfect much better than chlorine, formaldehyde or ethylene oxide, while being less toxic. Therefore, O 3 is often used to sterilize medical instruments, equipment, uniforms, and many drugs.

In industry, this substance is most often used for purification or extraction of many chemicals.

Another area of ​​use is the bleaching of paper, fabrics, and mineral oils.

In the chemical industry, O 3 not only helps to sterilize equipment, instruments and containers, but is also used to disinfect the products themselves (eggs, grain, meat, milk) and increase their shelf life. In fact, it is considered one of the best food preservatives because it is non-toxic and non-carcinogenic, and is also excellent at killing mold spores and other fungi and bacteria.

In bakeries, ozone is used to speed up the fermentation process of yeast.

Also, with the help of O 3, cognacs are artificially aged and fatty oils are refined.

How does ozone affect the human body?

Because of this similarity to oxygen, there is a misconception that ozone is a substance beneficial to the human body. However, this is not true, since O3 is one of the strongest oxidizing agents that can destroy the lungs and kill anyone who inhales this gas excessively. It is not for nothing that state environmental organizations in every country strictly monitor the concentration of ozone in the atmosphere.

If ozone is so harmful, then why does it always become easier to breathe after rain?

The fact is that one of the properties of O 3 is its ability to kill bacteria and purify substances from harmful impurities. When it rains due to a thunderstorm, ozone begins to form. This gas affects toxic substances contained in the air, breaking them down, and purifies oxygen from these impurities. It is for this reason that the air after rain is so fresh and pleasant, and the sky takes on a beautiful azure color.

These chemical properties of ozone, which allow it to purify the air, have recently been actively used to treat people suffering from various respiratory diseases, as well as to purify air, water, and various cosmetic procedures.

Today, household ozonizers that purify the air in the house using this gas are quite actively advertised. Although this technique seems to be very effective, scientists have not yet sufficiently studied the effect of large amounts of ozone-purified air on the body. For this reason, you should not get too carried away with ozonation.

OZONE, O3 OZONE, O3, allotropic form of oxygen; blue gas, boiling point - 111.95 shC. Ozone ensures the preservation of life on Earth, because The ozone layer of the atmosphere retains part of the ultraviolet radiation from the Sun and absorbs the infrared radiation of the Earth, preventing its cooling (see also Ozone hole). Ozone is used to disinfect drinking water, neutralize industrial wastewater, to obtain camphor, vanillin and other compounds, to bleach fabrics, mineral oils, etc. It was discovered by the German chemist H. Schönbein in 1840.

Modern encyclopedia. 2000 .

See what “OZONE, O3” is in other dictionaries:

- (new Greek, from Greek ozo to have a strong smell). Electrified oxygen, with a peculiar odor, chemically highly reactive. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. OZONE [gr. ozon smelling] gas,… … Dictionary of foreign words of the Russian language

OZONE, an unstable blue gaseous allotrope of OXYGEN (O3). Has a characteristic pungent odor. Decomposes into molecular oxygen. Present in the atmosphere, mainly in the OZONE LAYER, where it is formed from oxygen under the influence of... ... Scientific and technical encyclopedic dictionary

ozone- a, m. ozone m. gr. ozon smelling. A compound of three oxygen atoms; has a characteristic odor observed during a discharge of electricity; formed during a thunderstorm, or during a quiet electrical discharge or under the action of ultraviolet rays... Historical Dictionary of Gallicisms of the Russian Language

OZONE- (from the Greek ozon smelling), allotropic modification of oxygen (O3). It is highly chemically reactive and toxic. Blue gas with a pungent odor. Formed from O2 during an electrical discharge (for example, during a thunderstorm) and under the influence of... ... Ecological dictionary

Ozone- OZONE, O3, allotropic form of oxygen; blue gas, boiling point 111.95 °C. Ozone ensures the preservation of life on Earth, because The ozone layer of the atmosphere retains part of the ultraviolet radiation from the Sun and absorbs infrared radiation from the Earth, preventing... Illustrated Encyclopedic Dictionary

Gas, oxygen Dictionary of Russian synonyms. ozone noun, number of synonyms: 2 gas (55) oxygen ... Synonym dictionary

ozone- A form of oxygen, the proportion of which in the atmosphere is very small, but ozone is vital for the biosphere, as it absorbs the ultraviolet component of solar radiation... Dictionary of Geography