Median of a random variable. Mode and median

The process of producing the optimal amount of a chemical, as well as achieving its maximum quality, is influenced by a number of factors. The production of ammonia depends on pressure, temperature, the presence of a catalyst, the substances used and the method of extracting the resulting material. These parameters must be properly balanced to achieve the greatest profit from the production process.

Properties of ammonia

At room temperature and normal air humidity, ammonia is in gaseous state and has a very repulsive smell. It has a toxic and irritating effect on the mucous membranes on the body. The production and properties of ammonia depend on the participation of water in the process, since this substance is very soluble in normal characteristics environment.

Ammonia is a compound of hydrogen and nitrogen. Its chemical formula is NH 3.

This chemical substance acts as an active reducing agent, as a result of combustion of which free nitrogen is released. Ammonia exhibits the characteristics of bases and alkalis.

Reaction of a substance with water

When NH 3 is dissolved in water, ammonia water is obtained. At normal temperatures, a maximum of 700 volumes of ammonia can be dissolved in 1 volume of water element. This substance is known as ammonia and is widely used in the fertilizer production industry and in technological installations.

NH 3 obtained by dissolving in water is partially ionized in its properties.

Ammonia is used in one of the methods laboratory obtaining this element.

Obtaining a substance in the laboratory

The first method of producing ammonia is to bring ammonia to a boil, after which the resulting steam is dried and the required quantity is collected. chemical compound. It is also possible to obtain ammonia in the laboratory by heating slaked lime and solid ammonium chloride.

The reaction for producing ammonia has the following form:

2NH 4 Cl + Ca(OH) 2 → CaCl 2 + 2NH 3 + 2H 2 O

During this reaction a precipitate forms white. This is the salt CaCl 2, and water and the desired ammonia are also formed. To dry the required substance, it is passed through a mixture of lime in combination with soda.

Obtaining ammonia in the laboratory does not provide the most optimal technology for its production in the required quantities. People have been looking for ways to extract the substance on an industrial scale for many years.

The origins of establishing production technologies

During the years 1775-1780, experiments were carried out to bind free nitrogen molecules from the atmosphere. Swedish chemist K. Schelle found a reaction that looked like

Na 2 CO 3 + 4C + N 2 = 2NaCN + 3CO

On its basis, in 1895, N. Caro and A. Frank developed a method for binding free nitrogen molecules:

CaC 2 + N 2 = CaCN 2 + C

This option required a lot of energy and was not economically viable, so over time it was abandoned.

Another rather expensive method was the process of interaction between nitrogen and oxygen molecules discovered by the English chemists D. Priestley and G. Cavendish:

Increased demand for ammonia

In 1870, this chemical was considered an undesirable product of the gas industry and was practically useless. However, 30 years later it has become very popular in the coke industry.

At first, the increased need for ammonia was met by isolating it from coal. But with the consumption of the substance increasing 10 times, practical work was carried out to find ways to extract it. Ammonia production began to be introduced using atmospheric nitrogen reserves.

The need for nitrogen-based substances was observed in almost all known sectors of the economy.

Finding ways to meet industrial demand

Humanity has come a long way towards realizing the equation for the production of matter:

N2 + 3H2 = 2NH3

The production of ammonia in industry was first realized in 1913 by catalytic synthesis from hydrogen and nitrogen. The method was discovered by F. Haber in 1908.

Open technology has solved a long-standing problem of many scientists from different countries. Until this point, it was not possible to bind nitrogen in the form of NH 3. This chemical process called the cyanamide reaction. When the temperature of lime and carbon increased, the substance CaC 2 (calcium carbide) was obtained. By heating nitrogen, they achieved the production of calcium cyanamide CaCN 2, from which ammonia was released by hydrolysis.

Introduction of technologies for ammonia production

The production of NH 3 on a global industrial scale began with the purchase of a technology patent by F. Haber by the representative of the Baden Soda Factory, A. Mittash. At the beginning of 1911, the synthesis of ammonia in a small installation became regular. K. Bosch created a large contact apparatus based on the developments of F. Haber. This was the original equipment that provided the ammonia extraction process by synthesis on a production scale. K. Bosch took full leadership on this issue.

Saving energy costs implied participation in synthesis reactions of certain catalysts.

A group of scientists working to find suitable components proposed the following: an iron catalyst, to which potassium and aluminum oxides were added and which is still considered one of the best for producing ammonia in industry.

On September 9, 1913, the world's first plant using catalytic synthesis technology began operating. Production capacity was gradually increased, and by the end of 1917, 7 thousand tons of ammonia were produced per month. In the first year of operation of the plant, this figure was only 300 tons per month.

Subsequently, all other countries also began to use synthesis technology using catalysts, which in essence was not very different from the Haber-Bosch technique. The use of high pressure and circulation processes occurred in any technological process.

Introduction of synthesis in Russia

In Russia, synthesis was also used using catalysts to produce ammonia. The reaction looks like this:

In Russia, the very first ammonia synthesis plant began operating in 1928 in Chernorechensk, and then production facilities were built in many other cities.

Practical work on the production of ammonia is constantly gaining momentum. Between 1960 and 1970, synthesis increased almost 7-fold.

In the country, mixed catalytic substances are used to successfully obtain, collect and recognize ammonia. The study of their composition is carried out by a group of scientists led by S. S. Lachinov. It was this group that found the most effective materials for the synthesis technology.

Research into the kinetics of the process is also ongoing. Scientific developments M.I. Temkin, as well as his employees, led in this area. In 1938, this scientist, together with his colleague V. M. Pyzhev, made important discovery, improving the production of ammonia. The synthesis kinetics equation compiled by these chemists is now used throughout the world.

Modern synthesis process

The process of producing ammonia using a catalyst, used in today's production, is reversible. Therefore, the question of the optimal level of influence of indicators on achieving maximum output is very relevant.

The process takes place at high temperature: 400-500 ˚С. To ensure the required reaction rate, a catalyst is used. Modern production of NH 3 involves the use of high pressure - about 100-300 atm.

Together with the use of a circulation system, you can get enough large mass raw materials converted into ammonia.

Modern production

The operating system of any ammonia plant is quite complex and contains several stages. The technology for obtaining the desired substance is carried out in 6 stages. During the synthesis process, ammonia is produced, collected and recognized.

The initial stage involves extracting sulfur from natural gas using a desulfurizer. This manipulation is required due to the fact that sulfur is catalytic poison and kills the nickel catalyst at the stage of hydrogen extraction.

At the second stage, methane conversion takes place, which occurs using high temperature and pressure when using a nickel catalyst.

At the third stage, partial combustion of hydrogen occurs in the oxygen of the air. The result is a mixture of water vapor, carbon monoxide, and nitrogen.

In the fourth stage, a shift reaction occurs, which takes place under different catalysts and two different temperature conditions. Initially, Fe 3 O 4 is used, and the process takes place at a temperature of 400 ˚C. The second stage involves a more efficient copper catalyst, which allows production at low temperatures.

The next fifth stage involves getting rid of unnecessary carbon monoxide (VI) from the gas mixture by using alkali solution absorption technology.

At the final stage, carbon (II) monoxide is removed using a hydrogen to methane conversion reaction through a nickel catalyst and high temperature.

The gas mixture obtained as a result of all manipulations contains 75% hydrogen and 25% nitrogen. It is compressed under great pressure and then cooled.

It is these manipulations that are described by the ammonia release formula:

N 2 + 3H 2 ↔ 2 NH 3 + 45.9 kJ

Although this process does not look very complicated, all of the above steps for its implementation indicate the difficulty of producing ammonia on an industrial scale.

The quality of the final product is affected by the absence of impurities in the raw materials.

Having come a long way from small laboratory experience to large-scale production, the production of ammonia today is a popular and indispensable branch of the chemical industry. This process is constantly being improved to ensure quality, cost-effectiveness and required quantity product for each cell of the national economy.

Ammonia (NH 3) is one of the most common industrial chemicals used in industry and commerce.

Ammonia, why does our body need it? It turns out that it is constantly formed in all organs and tissues and is an essential substance in many biological processes, serves as a precursor for the formation of amino acids and nucleotide synthesis. In nature, ammonia is formed during the decomposition of nitrogen-containing organic compounds.

Chemical and physical properties of ammonia

• At room temperature, ammonia is a colorless, irritating gas with a pungent, suffocating odor;
• in its pure form is known as anhydrous ammonia;
• hygroscopic (easily absorbs moisture);
• has alkaline properties, caustic, easily soluble in water;
• easily compresses and forms a clear liquid under pressure.

Where is ammonia used?

About 80% of ammonia is used to make industrial products.

Ammonia is used in agriculture as fertilizer.

Present in refrigeration units for purifying aqueous compositions.

Used in the production of plastics, explosives, textiles, pesticides, dyes and other chemicals.

Contained in many household and industrial cleaning solutions. Household products containing ammonia are manufactured with the addition of 5-10% ammonia; the concentration of ammonia in industrial solutions is higher - 25%, which makes them more caustic.

How does ammonia affect the human body?

Most people come into contact with ammonia inhaling it like gas or evaporation. Since ammonia exists naturally and is found in detergents, they can be sources of it.

The widespread use of ammonia in agricultural and industrial areas also means that increased concentrations in the air can occur during accidental releases or deliberate terrorist attacks.

Anhydrous ammonia gas is lighter than air and therefore rises high, so it generally dissipates and does not accumulate in low areas. However, in the presence of dampness (increased relative humidity) liquefied anhydrous ammonia forms vapor that is heavier than air. These vapors can be carried over the surface of the earth or over lowlands.

How does ammonia work?

Ammonia begins to react immediately after contact with moisture on the surface of the skin, eyes, mouth, respiratory tract and partially mucous surfaces and forms a very caustic ammonium hydroxide . Ammonium hydroxide causes tissue necrosis due to violation cell membranes, leads to cell destruction. Once the protein and cells are broken down, water is extracted through an inflammatory response, leading to further damage.

What are the symptoms of ammonia poisoning?

Breath. The smell of ammonia in the nose is irritating and pungent. Contact with high concentrations of ammonia in the air leads to a burning sensation in the nose, throat and respiratory tract. This can lead to bronchiolar and alveolar edema and airway damage resulting from respiratory failure. Inhalation of low concentrations may cause coughing and irritation of the nose and throat. The smell of ammonia is a fairly early warning of its presence, but ammonia also leads to a weakened sense of smell, which reduces the ability to notice it in the air at low concentrations.

Children, exposed to the same amount of ammonia as adults, receive a larger dose because the surface area of ​​their lungs relative to their body is much larger. In addition, they may be more exposed to ammonia due to their short stature - they are closer to the ground, where the concentration of vapors is higher.

Contact with skin or eyes. Contact with low concentrations of ammonia in air or liquids may cause rapid irritation of the eyes or skin. Higher concentrations of ammonia can cause serious injury and burns . Contact with concentrated ammonia liquids, such as industrial detergents, may cause corrosion damage, including skin burns, eye damage or blindness . Highest degree eye lesions may not be visible for a week after exposure. Contact with liquefied ammonia may also cause frostbite .

Consumption with food. Exposure to high concentrations of ammonia through swallowing an ammonia solution can cause damage to the mouth, throat, and stomach.

10% aqueous solution ammonia . Concentration active substance per liter of solution - 440 ml.

As an auxiliary component, the drug contains purified water (in a volume of up to 1 liter).

Release form

Solution for inhalation and external use 10%. Available in 10 ml dropper bottles, 40 and 100 ml bottles.

It is a transparent, volatile liquid, colorless and with a pungent odor.

Pharmacological action

Annoying , antiseptic , analeptic , emetic .

Pharmacodynamics and pharmacokinetics

The product has an irritating effect on skin exteroreceptors and provokes local release prostaglandins , kinins And histamine . IN spinal cord acts as a liberator enkephalins And endorphins , which block the flow of pain impulses from pathological foci.

When it enters the upper respiratory tract, it interacts with the endings of the trigeminal nerve and reflexively excites the respiratory center. The concentrated solution causes colliquation (softening and dissolution) of microbial cell proteins.

With any method of administration, it is quickly eliminated from the body (mainly by the bronchial glands and lungs). Reflexively affects the tone of the vascular walls and the activity of the heart.

At the site of application, when applied externally, it dilates blood vessels, improves tissue regeneration and trophism, and also stimulates the outflow of metabolites.

When the skin is irritated, similar reflexes are caused in the segmentally located muscles and internal organs, contributing to the restoration of impaired functions and structures.

Suppresses the focus of excitation, which supports the pathological process, reduces muscle tension, hyperalgesia, relieves vascular spasm, thus providing a distracting effect.

With prolonged contact, it burns the mucous membranes and skin, which is accompanied by tissue hyperemia, the development of swelling and pain.

Oral administration in small concentrations stimulates the secretion of glands, affecting the vomiting center, reflexively increasing its excitability and causing vomiting.

The drug does not enter the bloodstream.

Indications for use

Inhalation is used to stimulate breathing during fainting.

Oral administration is indicated to stimulate vomiting (diluted).

Externally used to disinfect doctor's hands before surgery, in the form of lotions for neuralgia, insect bites, and myositis.

Contraindications

Intolerance.

Topical use is contraindicated for skin diseases.

Side effects: effects of ammonia vapors and solution on the human body

If the solution is taken undiluted, burns of the digestive canal (esophagus and stomach). Inhalation of the drug in high concentrations can provoke a reflex cessation of breathing.

Ammonia solution: instructions for use

The instructions for use of ammonia indicate that the dose of the drug is selected individually depending on the indications.

In surgical practice, the solution is used as a hand wash according to the Spasokukotsky-Kochergin method, diluting 50 ml of solution in 1 liter boiled water(warm).

When used to induce breathing, the solution is applied to gauze or cotton wool. For insect bites, it is used as a lotion.

The use of ammonia in gardening

The use of ammonia for plants is quite diverse: it is used against aphids, for treating onions against onion flies, and for feeding plants.

Ammonia for aphids is used at the rate of 2 tbsp. spoons per 10 liters of water. You should also add a little washing powder to the bucket - this will ensure better adhesion. The solution is used to spray plants.

Ammonia as a fertilizer: in this case, take 50 ml of solution per 4 liters of water. The product is not only a good fertilizer for indoor and garden plants, but also allows you to get rid of midges and mosquitoes.

To water the onions, dilute 1-2 tbsp in a bucket of water. spoons of ammonia. It is recommended to water plants with this product from the moment of planting until the end of June.

How to clean gold?

There are several ways to clean gold with ammonia.

You can mix 1 teaspoon of alcohol with a glass of water and 1 tbsp. spoon any detergent, or you can add to water (200 ml), ammonia (1 teaspoon), (30 ml), half a teaspoon of liquid detergent.

In the first case, the jewelry is placed in the cleaning solution for an hour or two, in the second - for 15 minutes. After cleaning, the gold should be rinsed in water and wiped dry with a napkin.

How to clean silver?

To clean silver, ammonia is diluted with water in a ratio of 1:10 (1 part alcohol to 10 parts water). Silver items are left in the solution for several hours, then rinsed in water and wiped with a soft cloth.

To regularly clean silver, use a soap solution to which you add small quantity ammonia.

Ammonia for cockroaches and ants

To combat ants, 100 ml of solution is diluted in a liter of water and the furniture in the kitchen is washed with this product. To get rid of cockroaches, wash the floor with ammonia.

Ammonia for heels

As a means to soften rough skin on the feet, ammonia is mixed with glycerin (1:1). The product is applied to the feet before going to bed, and socks are put on top.

Overdose. Impact of ammonia vapor on the human body

An overdose causes increased manifestations of adverse reactions. Thus, the effect on the human body of a high dose of ammonia solution when taken orally is manifested:

• vomiting with a characteristic odor of ammonia;
• diarrhea with tenesmus (false painful urge to defecate);
• swelling of the larynx;
• runny nose;
• cough;
• excitement;
• convulsions;
• collapse .

In some cases it is possible death (the patient dies when taking 10-15 g ammonium hydroxide ).

Treatment for overdose is symptomatic.

Sometimes people wonder what will happen if they drink ammonia. You should be aware that oral administration of the solution in its pure form can cause severe burns of the digestive canal.

Symptoms of ammonia poisoning

Human exposure to ammonia when inhaling its vapors manifests itself in the form of irritation of the mucous membranes of the eyes and respiratory tract. In this case, the intensity of irritation depends on the gas concentration.

Signs of ammonia vapor poisoning:

• profuse lacrimation;
• salivation;
• increased breathing;
• increased sweating;
• facial hyperemia;
• feeling of heaviness and tightness in the chest;
• chest pain;
• whooping cough;
• sneezing;
• runny nose;
• swelling of the larynx and spasm in the vocal cords;
• anxiety;
• suffocation;
• convulsions;
• loss of consciousness.

With prolonged exposure, ammonia vapor provokes severe muscle weakness, a person's blood circulation is impaired, symptoms indicating respiratory distress, as well as pain, severe burning and swelling of the skin occur.

Regularly repeated exposure to ammonia leads to problems systemic nature, which appear eating disorders , deafness , catarrh of the upper respiratory tract , heart failure , death .

To protect against harmful effects ammonia, rinse your face and skin unprotected by clothing with plenty of water and cover your face with a respirator (gauze bandage or gas mask) as soon as possible. It is good if the respirator or bandage used is soaked in water with citric acid (2 teaspoons per glass of water).

You should be aware that liquid ammonia causes severe burns. For this reason, it is transported in painted yellow steel cylinders, special tankers, road and railway tanks.

What to do if there is an ammonia release?

If you receive information about an ammonia leak, you should protect your skin and respiratory organs and leave the emergency area in the direction indicated in the radio or television message.

Out of the zone chemical damage need to go to perpendicular to the direction wind side.

In case of fire, it is prohibited to approach the source of fire. Containers containing ammonia should be cooled as much as possible. long distance. To extinguish, use air-mechanical foam or sprayed water.

If there is no way to leave, you should urgently seal the room. Getting out of danger zone, take off outer clothing (leave things outside), take a shower, rinse the nasopharynx and eyes with water.

In case of an accident, you should take shelter in the lower floors of the building.

First aid for poisoning

In case of poisoning, the victim should be taken out of the affected area. In cases where this is not possible, provide access to oxygen.

The mouth, throat and nasal cavity are washed with water for 15 minutes, the eyes are instilled with a 0.5% solution and, if necessary, additionally cover with a bandage. To make rinsing more effective, glutamic or citric acid can be added to the water.

Even with a slight degree of poisoning, the patient should be provided with absolute rest over the next 24 hours.

If the substance comes into contact with open area body, it is washed abundantly with water and covered with a bandage.

If ammonia enters the digestive canal, it is necessary to rinse the stomach.

Poisoning of any degree requires contacting a medical facility and, if the doctor deems it necessary, subsequent hospitalization.

After completing the course of treatment, the patient may retain certain neurological disorders, for example, loss of memory of individual events and facts, tics with various clinical manifestations, decreased hearing and pain sensitivity threshold. A common outcome is clouding of the lens and cornea of ​​the eye.

Ammonia: ways of neutralization in the body

The main route of binding of the substance is the biosynthesis of urea, which occurs in the ornithine cycle in liver cells. As a result of this synthesis, urea - a substance that is not harmful to the body.

Ammonia is also transported in the blood in the form glutamine , which is a non-toxic neutral compound and easily passes through cell membranes.

Another transport form of it is formed in the muscles alanine .

Interaction

Neutralizes the effects of acids.

Terms of sale

Over-the-counter product.

Storage conditions

Stored under normal conditions.

Best before date

24 months.

Special instructions

What is ammonia? Characteristics, physical and chemical properties of ammonia

Ammonia or hydrogen nitride (NH3) is a colorless gas (like hydrogen, ether, oxygen). The substance has a strong irritating odor and releases into the atmosphere producing smoke. Name of the substance on Latin— Ammonium.

Molar mass - 17.0306 g/mol. MPC r.z. is 20 mg/m3. Taking into account this parameter, ammonia is classified as a low-hazard substance (hazard class IV).

NH3 is extremely soluble in water: at 0°C, about 1.2 thousand volumes of this substance dissolve in one volume of water, and at a temperature of 20°C - about 700 volumes.

It has the properties of alkalis and bases.

Used as a refrigerant for refrigeration equipment. It is marked R717, where R stands for “refrigerant” (Refrigerant), “7” indicates the type of refrigerant (in this particular case, that ammonia is not an organic substance), the last 2 digits are the molecular weight of the substance used.

In liquid hydrogen nitride, the molecules form hydrogen bonds. Permittivity, conductivity, viscosity and density of liquid NH3 are lower than that of water (the substance is 7 times less viscous than water), the boiling point of the substance is bp -33.35°C, it begins to melt at a temperature of -77.70°C

Like water, liquid NH3 is a highly associated substance due to the formation of hydrogen bonds.

The substance is practically impermeable electric current and dissolves many organic and inorganic compounds.

In solid form, NH3 appears as colorless crystals with a cubic lattice.

The decomposition of hydrogen nitride into nitrogen and hydrogen becomes noticeable at temperatures exceeding 1200-1300°C, in the presence of catalysts - at temperatures above 400°C.

Ammonia does not burn in air, but under other conditions, namely in pure oxygen, it ignites and burns with a yellow-green flame. When a substance burns in excess oxygen, nitrogen and water vapor are formed.

The combustion reaction of ammonia is described the following equation: 4NH3 + 3O2= 2N2 + 6H2O.

Catalytic oxidation of NH3 at a temperature of 750-800°C allows one to obtain nitric acid (the method is used for the industrial production of HNO3).

Process stages:

• catalytic oxidation with oxygen to NO;
• conversion of NO to NO2;
• absorption of a mixture of NO2 and O2 by water (dissolution of nitric oxide in water and production of acid);
• purification of gases released into the atmosphere from nitrogen oxides.

The reaction of ammonia with water produces ammonia hydrate (ammonia water or caustic ammonia). The chemical formula of the hydrate is NH3·H2O.

How is caustic ammonia produced in industry? In industry, the synthesis of an ammonia solution with a concentration of 25% is carried out by saturating water with ammonia, which is formed as a result of coking coal in a coke oven, or with synthetic ammonia gas.

What is ammonia water used for? Nitrogen fertilizers, soda, and dyes are obtained from aqueous solutions of ammonia.

Ammonia: obtaining from nitric acid in the laboratory

To obtain NH3 from HNO3, place the test tube in a stand at almost horizontal position, but so that the acid does not flow out of it.

A few drops of HNO3 are poured into the bottom of the test tube and a few pieces of zinc or iron filings. Reduced iron should be placed at the opening of the test tube (so that it does not come into contact with nitric acid).

The test tube must be closed with a stopper with an outlet tube and slightly heated. Heating will increase the rate of ammonia release.

What does ammonia react with?

Ammonia reacts with organic substances. Products of the reaction of ammonia with α-chloro-substituted carboxylic acids are artificial amino acids.

As a result of the reaction, hydrogen chloride (HCl gas) is released, which, when combined with excess ammonia, forms NH4Cl (or ammonia).

A large number of complex compounds contain ammonia as a ligand.

Ammonium salts are colorless solids with a crystal lattice. Almost all of them are soluble in water, and they have the same properties as the metal salts known to us.

The product of their interaction with alkalis is ammonia:

NH4Cl + KOH = KCl + NH3 + H2O

The reaction described by the formula, if indicator paper is additionally used, is a qualitative reaction to ammonium salts. The latter interact with acids and other salts.

Some ammonium salts evaporate (sublimate) when heated, while others decompose.

NH3 is a weak base, so the salts it forms in an aqueous solution undergo hydrolysis.

Weaker bases than ammonia are aromatic amines - NH3 derivatives in which hydrogen atoms are replaced by hydrocarbon radicals.

Reactions of ammonia with acids

Adding concentrated NH3 to the solution hydrochloric acid accompanied by education white smoke and the release of ammonium chloride NH4Cl (ammonia).

The reaction of sulfuric acid and ammonia produces white crystals of (NH4)2SO4 - ammonium sulfate.

If you add nitric acid to NH3, white ammonium nitrate NH4 NO3 is formed.

When chloroacetic acid reacts with NH3, the chlorine atom is replaced by an amino group, resulting in the formation of aminoacetic acid.

If NH3 is passed through hydrobromic acid, ammonium bromide is formed (the reaction is described by the formula - HBr + NH3 = NH4Br).

Ammonia: heavier or lighter than air?

Compared to air, NH3 has almost half the density, so its vapor always rises. However, under certain conditions, an ammonia aerosol can form - a suspension of droplets of this substance in a gas. This aerosol is usually heavier than air and is therefore more dangerous than NH3 gas.

Is hydrogen nitride a complex or a simple substance?

Hydrogen nitride is formed by atoms different elements, therefore it is a complex inorganic compound.

Molecular structure of ammonia

Ammonia is characterized by crystal lattice of polar molecules between which the so-called van der Waals forces . There are 3 chemical bonds in the hydrogen nitride molecule; they are formed by a covalent polar mechanism.

The molecule has the shape of a trigonal pyramid, at the top of which there is a nitrogen atom (the oxidation state of nitrogen in NH3 is “-3”).

Industrial method for producing ammonia

Producing ammonia in industry is an expensive and labor-intensive process. Industrial synthesis is based on the production of NH3 from nitrogen and hydrogen under pressure, in the presence of a catalyst and at high temperatures.

Sponge iron activated by aluminum and potassium oxides is used as a catalyst in the production of NH3 in industry. Industrial installations in which synthesis is carried out are based on the circulation of gases.

Reacted gas mixture, which contains NH3, is cooled, after which the NH3 condenses and separates, and the hydrogen and nitrogen that have not reacted with a new portion of gases are again supplied to the catalyst.

There was also a presentation on the topic of co-production of ammonia and methanol in industry.

Current GOSTs, in accordance with which hydrogen nitride is produced:

• technical liquid ammonia, anhydrous ammonia - GOST 6221-90;
• aqueous ammonia - GOST 3760-79;
• technical ammonia aqueous - GOST 9-92.

The ammonia synthesis reaction can be characterized as follows: ammonia is formed as a product of a compound reaction occurring in the gas phase - direct, catalytic, exothermic, reversible, redox.

Disposal of the substance

NH3 is recycled by selectively obtaining substances that are valuable for recycling, and by a method that provides for the possibility of using waste waste as raw material for the production of other materials.

What is ammonia? Chemical formula of ammonia

Ammonia is a 10% aqueous solution of ammonia. The formula of the substance is NH4OH. The name in Latin is Solutio Ammonii caustici seu Ammonium causticum solutum.

Ammonia has found use in everyday life as a stain remover, a means for cleaning coins, dishes, plumbing fixtures, furniture, and silver and gold jewelry. In addition, it is used for dyeing fabrics, fighting aphids, onion secrecy, onion flies, ants and cockroaches, washing windows, and caring for rough skin of the feet.

The reaction of ammonia with allows one to obtain a very unstable adduct, which has the appearance of dry crystals, which is often used as a spectacular experiment.

Is ammonia ammonia?

Some people believe that ammonia and ammonia are the same thing. However, this opinion is wrong. Ammonia solution is ammonia or, in other words, an aqueous solution of ammonium hydroxide.

A ammonia is an ammonium salt, a slightly hygroscopic, white and odorless crystalline powder that, when heated, vaporizes hydrogen nitride (ammonia). Its formula is NH4Cl.

Wikipedia indicates that the substance is used as a fertilizer (as a top dressing it is applied to alkaline and neutral soils under crops that react poorly to excess chlorine - rice, corn, sugar beets), as food additives E510, soldering flux, electrolyte components galvanic cells and a quick fixer in photography, a smoke generator.

In laboratory conditions, ammonia is used for lysis red blood cells , use in medicine is advisable to enhance the effect diuretics and relieving edema of cardiac origin.

Precautions

Topical application is possible only on intact skin.

In case of accidental contact of the product with the mucous membrane of the eyes, wash the eyes with plenty of water (for at least 15 minutes) or a solution of boric acid (3%). Oils and ointments are contraindicated in this case.

If you take an ammonia solution orally, you should drink fruit juices, water, warm milk with soda or mineral water, a solution of citric (0.5%) or acetic (1%) acid until it is completely neutralized.

In case of damage to the respiratory system, indicated fresh air and warm water inhalations with the addition of citric acid or vinegar; in case of suffocation - oxygen.

What do the smell of ammonia in urine and the ammonia smell of sweat indicate? .

You should know that about serious The smell of ammonia from the mouth is also evidenced.

In women, discharge with an odor is possible during menopause and pregnancy (if the pregnant woman drinks little fluid and/or takes various medications and supplements).

If your sweat smells like ammonia, it may be due to , , urinary incontinence, liver problems, the presence of bacteria that can cause peptic ulcers. One more possible reason body odor - following a protein diet.

Everyone knows what ammonia smells like, so if a characteristic odor appears (especially if a child’s urine smells) or an ammonia taste in the mouth, you should consult a doctor, who will accurately determine the cause of this phenomenon and take the necessary measures.

For children

In pediatrics it is used from 3 years of age.

During pregnancy

During pregnancy and lactation, use is allowed only in situations where the benefit to the woman’s body outweighs the potential risk to the child.

In most cases, pregnant women try not to use ammonia in any form. Maternity dye should also not contain this substance. The list of products most suitable for pregnant women includes the following ammonia-free hair dyes:

• Igora Schwarzkopf (Schwarzkopf Igora Vibrance);
• paints from the Garnier palette (Garnier Color&Shine);
• Estelle paint, the palette of which includes 140 shades;
• ammonia-free paint from the Matrix Color Sync palette;
• Kutrin paint.

Quite a lot good reviews and about L’Oreal ammonia-free paint (L’Oreal Professionnel LUO COLOR). However, there are women who continue to use ammonia hair dye during pregnancy.

Ammonia is a compound that is the most important source nitrogen for living organisms, and also found application in various industries industry. What is ammonia, what are its properties? Let's figure it out.

What is ammonia: main characteristics

Ammonia (water nitride) is a compound of nitrogen and hydrogen that has chemical formula NH3. The shape of the molecule resembles a trigonal pyramid, at the top of which is a nitrogen atom.

Ammonia is a gas that is colorless but has a strong, specific odor. The density of ammonia is almost two times less than the density of air. At a temperature of 15 o C it is 0.73 kg/m 3. The density of liquid ammonia under normal conditions is 686 kg/m3. Molecular weight substances - 17.2 g/mol. Distinctive feature ammonia is its high solubility in water. Thus, at a temperature of 0 °C its value reaches about 1200 volumes in a volume of water, at 20 °C - 700 volumes. The ammonia - water solution (ammonia water) is characterized by a slightly alkaline reaction and a rather unique property compared to other alkalis: with increasing concentration, the density decreases.

How is ammonia formed?

What is ammonia in the human body? This is the end product of nitrogen metabolism. The liver converts most of it into urea (carbamide), a less toxic substance.

Ammonia under natural conditions is formed as a result of the decomposition of organic compounds containing nitrogen. For industrial use, this substance is obtained artificially.

Production of ammonia in industrial and laboratory conditions

Under industrial conditions, ammonia is produced by catalytic synthesis from nitrogen and hydrogen:

N 2 + 3H 2 → 2NH3 + Q.

The process of obtaining the substance is carried out at a temperature of 500 °C and a pressure of 350 atm. The resulting ammonia is used as a catalyst and is removed by cooling. Nitrogen and hydrogen that have not reacted are returned to synthesis.

In laboratory conditions, ammonia is obtained mainly by low heat a mixture consisting of ammonium chloride and slaked lime:

2NH 4 Cl + Ca(OH) 2 → CaCl 2 + 2NH 3 + 2H 2 O.

To dry, the finished compound is passed through a mixture of lime and caustic soda. Fairly dry ammonia can be obtained by dissolving sodium metal in it and then distilling it.

Where is ammonia used?

Hydrogen nitride is widely used in various industries. Huge quantities of it are used for various fertilizers (urea, ammonium nitrate, etc.), polymers, hydrocyanic acid, soda, ammonium salts and other types of chemical products.

IN light industry The properties of ammonia are used in cleaning and dyeing fabrics such as silk, wool and cotton. In steelmaking, it is used to increase the hardness of steel by saturating its surface layers with nitrogen. In the petrochemical industry, acid waste is neutralized using hydrogen nitride.

Due to its thermodynamic properties, liquid ammonia is used as a refrigerant in refrigeration equipment.

NH 3 + HNO 3 → NH 4 NO 3.

When reacting with HCl, ammonium chloride is formed:

NH 3 + HCl → NH 4 Cl.

Ammonium salts are solid crystalline substances, decompose in water and have properties inherent in metal salts. Solutions of compounds formed as a result of the interaction of ammonia and strong acids, have a slightly acidic reaction.

Due to the nitrogen atoms, hydrogen nitride is an active reducing agent. Restorative properties it appears when heated. When burned in an oxygen atmosphere, it forms nitrogen and water. In the presence of catalysts, interaction with oxygen gives hydrogen nitride the ability to reduce metals from oxides.

Halogens react with ammonia to form nitrogen halides - dangerous explosives. When interacting with carboxylic acids and their derivatives, hydrogen nitride forms amides. In reactions with coal (at 1000 °C) and methane it gives

With metal ions, ammonia forms amino complexes, or ammonia ( complex compounds), having characteristic feature: A nitrogen atom is always bonded to three hydrogen atoms. As a result of complexation, the color of the substance changes. So, for example, when hydrogen nitride is added, a blue solution acquires an intense blue-violet color. Many of the amino complexes are quite stable. Thanks to this, they can be obtained in solid form.

Both ionic and non-polar inorganic and organic compounds dissolve well in liquid ammonia.

Sanitary and hygienic characteristics

Ammonia is classified as the fourth maximum permissible single-time concentration (MPC) in the air settlements is equal to 0.2 mg/m 3, the daily average is 0.04. The ammonia content in the air of the working area should not exceed 20 mg/m³. At such concentrations the odor of the substance is not noticeable. It begins to be detected by the human sense of smell at 37 mg/m³. That is, if the smell of ammonia is felt, this means that acceptable standards the presence of the substance in the air is significantly exceeded.

Effect on the human body

What is ammonia in terms of human exposure? It's toxic. It is classified as a substance that can have a suffocating and neurotropic effect, inhalation poisoning of which can lead to pulmonary edema and damage nervous system.

Ammonia vapors irritate the skin, mucous membranes of the eyes and respiratory organs. The concentration of the substance at which irritation of the pharynx occurs is 280 mg per cubic meter. meter, eye - 490 mg per cubic meter. meter. Depending on the amount of hydrogen nitride in the air, a sore throat, difficulty breathing, coughing attacks, pain in the eyes, excessive lacrimation, chemical burns of the cornea, and loss of vision may occur. With an ammonia content of 1.5 g per cubic meter. meter within an hour toxic pulmonary edema develops. Contact of liquid ammonia and its solutions (in high concentrations) with the skin may cause redness, itching, burning, and dermatitis. Since liquefied water line nitride absorbs heat as it evaporates, frostbite of varying degrees is possible.

Symptoms of ammonia poisoning

Poisoning with this toxicant can cause a decrease in the hearing threshold, nausea, dizziness, headache etc. Changes in behavior are possible, in particular strong excitement, nonsense. The manifestation of symptoms in some cases is intermittent. They may stop for a while, and then resume with renewed vigor.

Considering all the possible consequences of exposure to ammonia, it is very important to take precautions when working with this substance and not to allow its concentration in the air to exceed.

Ammonia –N.H. 3

Ammonia (in European languages its name sounds like “ammoniac”) owes its name to the oasis of Ammon in North Africa, located at the crossroads of caravan routes. In hot climates, urea (NH 2) 2 CO, contained in animal waste products, decomposes especially quickly. One of the decomposition products is ammonia. According to other sources, ammonia got its name from the ancient Egyptian word Amonian. This was the name given to people who worshiped the god Amon. During their rituals, they sniffed ammonia NH 4 Cl, which, when heated, evaporates ammonia.

1. Molecule structure

The ammonia molecule has the shape of a trigonal pyramid with a nitrogen atom at the apex. Three unpaired p-electrons of the nitrogen atom participate in the formation of polar covalent bonds with the 1s-electrons of three hydrogen atoms (N−H bonds), the fourth pair of outer electrons is lone, it can form a donor-acceptor bond with a hydrogen ion, forming an ammonium ion NH 4 + .

View chemical bond: covalent polar, three singleσ - sigma N-H bonds

2. Physical properties of ammonia

Under normal conditions, it is a colorless gas with a sharp characteristic odor (the smell of ammonia), almost twice as light as air, and poisonous.According to its physiological effect on the body, it belongs to the group of substances with asphyxiating and neurotropic effects, which, if inhaled, can cause toxic pulmonary edema and severe damage to the nervous system. Ammonia vapors strongly irritate the mucous membranes of the eyes and respiratory organs, as well as the skin. This is what we perceive as a pungent odor. Ammonia vapors cause excessive lacrimation, eye pain, chemical burns of the conjunctiva and cornea, loss of vision, coughing attacks, redness and itching of the skin. The solubility of NH 3 in water is extremely high - about 1200 volumes (at 0 °C) or 700 volumes (at 20 °C) per volume of water.

3.

4. Chemical properties ammonia

Ammonia is characterized by the following reactions:

1. with a change in the oxidation state of the nitrogen atom (oxidation reaction)
2. without changing the oxidation state of the nitrogen atom (addition)

5. Application of ammonia

In terms of production volumes, ammonia occupies one of the first places; Every year, about 100 million tons of this compound are produced worldwide. Ammonia is available in liquid form or in the form of an aqueous solution - ammonia water, which usually contains 25% NH 3. Huge quantities of ammonia are then used to produce nitric acid which goes to fertilizer production and many other products. Ammonia water is also used directly as fertilizer, and sometimes fields are watered directly from tanks with liquid ammonia. From ammonia receive various ammonium salts, urea, methenamine. His also used as a cheap refrigerant in industrial refrigeration units.

Ammonia is also used for producing synthetic fibers, for example, nylon and nylon. In light industry he used in cleaning and dyeing cotton, wool and silk. In the petrochemical industry, ammonia is used to neutralize acid waste, and in the natural rubber industry, ammonia helps preserve latex as it travels from plantation to factory. Ammonia is also used in the production of soda using the Solvay method. In the steel industry, ammonia is used for nitriding - saturating the surface layers of steel with nitrogen, which significantly increases its hardness.

Doctors use aqueous solutions ammonia (ammonia) in everyday practice: a cotton swab dipped in ammonia brings a person out of a fainting state. Ammonia in this dose is not dangerous for humans.

EXERCISES

Simulator No. 1 "Ammonia combustion"

Simulator No. 2 "Chemical properties of ammonia"

ASSIGNMENT TASKS

№1. Carry out transformations according to the scheme:

a) Nitrogen → Ammonia → Nitric oxide (II)

b) Ammonium nitrate → Ammonia → Nitrogen

c) Ammonia → Ammonium Chloride → Ammonia → Ammonium Sulfate