2 N H 3 + N a O C l ⟶ N 2 H 4 + N a C l + H 2 O (\displaystyle (\mathsf (2NH_(3)+NaOCl\longrightarrow N_(2)H_(4)+NaCl+H_( 2)O)))

• Halogens (chlorine, iodine) form dangerous explosives with ammonia - nitrogen halides (nitrogen chloride, nitrogen iodide).

• Ammonia reacts with halogenated alkanes through nucleophilic addition, forming a substituted ammonium ion (method for producing amines):

• It produces amides with carboxylic acids, their anhydrides, acid halides, esters and other derivatives. With aldehydes and ketones - Schiff bases, which can be reduced to the corresponding amines (reductive amination).

Story

Ammonia was first isolated in its pure form by J. Priestley in 1774, who called it “alkaline air”. Eleven years later, in 1785, C. Berthollet established the exact chemical composition of ammonia. Since that time, research has begun around the world on producing ammonia from nitrogen and hydrogen. Ammonia was very necessary for the synthesis of nitrogen compounds, since their production from Chilean saltpeter was limited by the gradual depletion of the latter's reserves. The problem of decreasing nitrate reserves became more acute towards the end of the 19th century. Only at the beginning of the 20th century was it possible to invent a process for the synthesis of ammonia suitable for industry. This was carried out by F. Haber, who began working on this problem in 1904 and by 1909 created a small contact apparatus in which he used increased pressure (in accordance with Le Chatelier’s principle) and an osmium catalyst. On July 2, 1909, Haber tested the apparatus in the presence of K. Bosch and A. Mittash, both from the Baden Aniline and Soda Factory (BASF), and obtained ammonia. By 1911, K. Bosch had created a large-scale version of the apparatus for BASF, and then the world's first ammonia synthesis plant was built and put into operation on September 9, 1913, which was located in Oppau (now a district within the city of Ludwigshafen am Rhein) and belonged to BASF. In 1918, F. Haber won the Nobel Prize in Chemistry “for the synthesis of ammonia from its constituent elements.” In Russia and the USSR, the first batch of synthetic ammonia was produced in 1928 at the Chernorechensky chemical plant.

origin of name

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 Amun. During their rituals, they sniffed ammonia NH 4 Cl, which, when heated, evaporates ammonia.

Liquid ammonia

Liquid ammonia, although to a small extent, dissociates into ions (autoprotolysis), which shows its similarity to water:

The self-ionization constant of liquid ammonia at −50 °C is approximately 10 −33 (mol/l)².

The metal amides resulting from the reaction with ammonia contain a negative ion NH 2 −, which is also formed during the self-ionization of ammonia. Thus, metal amides are analogues of hydroxides. The reaction rate increases when going from Li to Cs. The reaction is significantly accelerated in the presence of even small impurities of H 2 O.

Metal-ammonia solutions have metallic electrical conductivity; in them, metal atoms decompose into positive ions and solvated electrons surrounded by NH 3 molecules. Metal-ammonia solutions, which contain free electrons, are the strongest reducing agents.

Complexation

Due to their electron-donating properties, NH 3 molecules can enter complex compounds as ligands. Thus, the introduction of excess ammonia into solutions of d-metal salts leads to the formation of their amino complexes:

Complexation is usually accompanied by a change in the color of the solution. So, in the first reaction, the blue color (CuSO 4) turns into dark blue (the color of the complex), and in the second reaction the color changes from green (Ni (NO 3) 2) to blue-violet. The strongest complexes with NH 3 are formed by chromium and cobalt in the oxidation state +3.

Biological role

Ammonia is an important source of nitrogen for living organisms. Despite the high content of free nitrogen in the atmosphere (more than 75%), very few living creatures are able to use free, neutral diatomic nitrogen of the atmosphere, N2 gas. Therefore, to include atmospheric nitrogen into biological circulation, in particular into the synthesis of amino acids and nucleotides, a process called “nitrogen fixation” is necessary. Some plants depend on the availability of ammonia and other nitrogenous residues released into the soil by the decaying organic remains of other plants and animals. Some others, such as nitrogen-fixing legumes, take advantage of a symbiosis with nitrogen-fixing bacteria (rhizobia), which are capable of producing ammonia from atmospheric nitrogen.

In some organisms, ammonia is formed from atmospheric nitrogen using enzymes called nitrogenases. This process is called nitrogen fixation. Although it is unlikely that biomimetic methods will ever be developed that can compete in productivity with chemical methods for producing ammonia from nitrogen, scientists are nevertheless making great efforts to better understand the mechanisms of biological nitrogen fixation. Scientific interest in this problem is partly motivated by the unusual structure of the active catalytic center of the nitrogen-fixing enzyme (nitrogenase), which contains an unusual bimetallic molecular ensemble Fe 7 MoS 9 .

Ammonia is also an end by-product of amino acid metabolism, namely the product of deamination catalyzed by enzymes such as glutamate dehydrogenase. Excretion of unchanged ammonia is a common route for ammonia detoxification in aquatic creatures (fish, aquatic invertebrates, and some amphibians). In mammals, including humans, ammonia is usually quickly converted to urea, which is much less toxic and, in particular, less alkaline and less reactive as a reducing agent. Urea is the main component of urine solids. Most birds, reptiles, insects, and arachnids, however, emit uric acid rather than urea as the main nitrogen residue.

Ammonia also plays an important role in both normal and pathological animal physiology. Ammonia is produced during normal amino acid metabolism, but is highly toxic in high concentrations. Animal livers convert ammonia to urea through a series of sequential reactions known as the urea cycle. Impaired liver function, such as that seen in cirrhosis, can impair the liver's ability to detoxify ammonia and convert it into urea, resulting in elevated levels of ammonia in the blood, a condition called hyperammonemia. A similar result - an increase in the level of free ammonia in the blood and the development of hyperammonemia - is caused by the presence of congenital genetic defects in urea cycle enzymes, such as ornithine carbamyltransferase. The same result can be caused by a violation of the excretory function of the kidneys in severe renal failure and uremia: due to a delay in the release of urea, its level in the blood increases so much that the “urea cycle” begins to work “in the opposite direction” - excess urea is hydrolyzed back by the kidneys into ammonia and carbon dioxide gas, and as a result, the level of ammonia in the blood increases. Hyperammonemia contributes to disturbances of consciousness and the development of soporous and comatose states in hepatic encephalopathy and uremia, as well as to the development of neurological disorders often observed in patients with congenital defects of urea cycle enzymes or organic acidurias.

Less pronounced, but clinically significant, hyperammonemia can be observed in any process in which increased protein catabolism is observed, for example, with extensive burns, tissue compression or crush syndrome, extensive purulent-necrotic processes, gangrene of the extremities, sepsis, etc., and also for some endocrine disorders, such as diabetes mellitus, severe thyrotoxicosis. The likelihood of hyperammonemia occurring in these pathological conditions is especially high in cases where the pathological condition, in addition to increased protein catabolism, also causes a pronounced impairment of the detoxifying function of the liver or the excretory function of the kidneys.

Ammonia is important for maintaining normal acid-base balance in the blood. After the formation of ammonia from glutamine, alpha-ketoglutarate can be further broken down to form two molecules of bicarbonate, which can then be used as a buffer to neutralize dietary acids. The ammonia obtained from glutamine is then excreted in the urine (both directly and in the form of urea), which, taking into account the formation of two bicarbonate molecules from ketoglutarate, results in a total loss of acids and a shift in blood pH to the alkaline side. In addition, ammonia can diffuse through the renal tubules, combine with the hydrogen ion and be excreted together with it (NH 3 + H + => NH 4 +), and thereby further promote the removal of acids from the body.

Ammonia and ammonium ions are a toxic byproduct of metabolism in animals. In fish and aquatic invertebrates, ammonia is released directly into the water. In mammals (including aquatic mammals), amphibians, and sharks, ammonia is converted to urea in the urea cycle because urea is much less toxic, less chemically reactive, and can be more efficiently “stored” in the body until it can be excreted. In birds and reptiles, ammonia produced during metabolism is converted to uric acid, which is a solid residue and can be excreted with minimal loss of water.

Physiological action

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 has both local and resorptive effects.

Ammonia vapors strongly irritate the mucous membranes of the eyes and respiratory organs, as well as the skin. This is what a person perceives 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. When liquefied ammonia and its solutions come into contact with the skin, a burning sensation occurs, and a chemical burn with blisters and ulcerations is possible. In addition, liquefied ammonia absorbs heat when it evaporates, and when it comes into contact with the skin, frostbite of varying degrees occurs. The smell of ammonia is felt at a concentration of 37 mg/m³.

Application

Ammonia is one of the most important products of the chemical industry; its annual global production reaches 150 million tons. Mainly used for the production of nitrogen fertilizers (ammonium nitrate and sulfate, urea), explosives and polymers, nitric acid, soda (using the ammonia method) and other chemical industry products. Liquid ammonia is used as a solvent.

Ammonia. Physical and chemical properties Chemical properties Due to the presence of a lone electron pair, ammonia acts as a complexing agent in many reactions. It adds a proton to form an ammonium ion. An aqueous solution of ammonia (“ammonia”) has a slightly alkaline environment due to the process: O > +; Ko=1, 8?10 -5 . (16) Interacting with acids, it gives the corresponding ammonium salts: 2(O) + > (+ O. (17) Ammonia is also a very weak acid and is capable of forming salts with metals - amides. When heated, ammonia exhibits reducing properties. So, it burns in an oxygen atmosphere, forming water and nitrogen. The oxidation of ammonia with air on a platinum catalyst produces nitrogen oxides, which are used industrially to produce nitric acid: 4 + 54NO + 6O. (18) The use of ammonia Cl to clean the metal surface from oxides during soldering is based on its reducing ability: 3CuO + 2Cl > 3Cu + 3O +2HCl +. (19) With haloalkanes, ammonia reacts with nucleophilic addition, forming a substituted ammonium ion (method for producing amines): Cl > (methyl ammonium hydrochloride). (20) It produces amides with carboxylic acids, their anhydrides, acid halides, esters and other derivatives. With aldehydes and ketones - Schiff bases, which can be reduced to the corresponding amines (reductive amination). At 1000 °C, ammonia reacts with coal, forming hydrocyanic acid HCN and partially decomposing into nitrogen and hydrogen. It can also react with methane, forming the same hydrocyanic acid: Liquid ammonia Liquid ammonia, although to a small extent, dissociates into ions, which shows its similarity to water: Liquid ammonia, like water, is a strong ionizing solvent in which a number of active metals dissolve: alkali, alkaline earth, Mg, Al, as well as Eu and Yb. The solubility of alkali metals in liquid is several tens of percent. Some intermetallic compounds containing alkali metals also dissolve in liquid ammonia, for example Dilute solutions of metals in liquid ammonia are colored blue, concentrated solutions have a metallic sheen and look like bronze. When ammonia evaporates, alkali metals are released in pure form, and alkaline earth metals are released in the form of complexes with ammonia 2+ having metallic conductivity. When heated slightly, these complexes decompose into metal and. Dissolved in the metal gradually reacts to form an amide: Complexation Due to their electron-donating properties, molecules can enter complex compounds as ligands. Thus, the introduction of excess ammonia into solutions of d-metal salts leads to the formation of their amino complexes: Complexation is usually accompanied by a change in the color of the solution, so in the first reaction the blue color () turns into dark blue, and in the second reaction the color changes from green (Ni() to blue-violet. The most stable complexes with form chromium and cobalt in the oxidation state ( +3). Solutions of ammonia are quite stable, with the exception of yellow-brown cobalt (II) ammonia, which is gradually oxidized by atmospheric oxygen into cherry-red cobalt (III) ammonia. In the presence of oxidizing agents, this reaction occurs instantly. The formation and destruction of a complex ion is explained by a shift in the equilibrium of its dissociation. In accordance with Le Chatelier's principle, the equilibrium in a solution of the ammonia complex of silver shifts towards the formation of the complex (to the left) with increasing concentration and/or. As the concentration of these particles in the solution decreases, the equilibrium shifts to the right and the complex ion is destroyed. This may be due to the binding of the central ion or ligands into some compounds that are stronger than the complex. For example, when nitric acid is added to a solution, the complex is destroyed due to the formation of ions in which ammonia is more tightly bound to the hydrogen ion: Ammonia production The industrial method for producing ammonia is based on the direct interaction of hydrogen and nitrogen: This is the so-called Garber process. The reaction occurs with the release of heat and a decrease in volume. Therefore, based on Le Chatelier's principle, the reaction should be carried out at the lowest possible temperatures and at high pressures - then the equilibrium will be shifted to the right. However, the reaction rate at low temperatures is negligible, and at high temperatures the rate of the reverse reaction increases. The use of a catalyst (porous iron with impurities and) made it possible to accelerate the achievement of an equilibrium state. Interestingly, when searching for a catalyst for this role, more than 20 thousand different substances were tried. Taking into account all the above factors, the process of producing ammonia is carried out under the following conditions: temperature 500 °C, pressure 350 atmospheres, catalyst. In industrial conditions, the circulation principle is used - ammonia is removed by cooling, and unreacted nitrogen and hydrogen are returned to the synthesis column. This turns out to be more economical than achieving a higher reaction yield by increasing the pressure. To obtain ammonia in the laboratory, the action of strong alkalis on ammonium salts is used: Usually, in a laboratory method, it is obtained by gently heating a mixture of ammonium chloride and slaked lime. To dry ammonia, it is passed through a mixture of lime and caustic soda. Subject: Ammonia. Physical and chemical properties. Receipt and application. Lesson objectives: know the structure of the ammonia molecule, physical and chemical properties, areas of application; be able to prove the chemical properties of ammonia: write down equations for the reactions of ammonia with oxygen, water, acids and consider them from the point of view of the theory of electrolytic dissociation and redox processes. During the classes 1. Organizational moment of the lesson. 2. Studying new material. Ammonia – NH 3 Ammonia (in European languages ​​its name sounds like “ammoniac”) owes its name to the Ammon oasis 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 ritual ceremonies 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 + . 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 has both local and resorptive effects. 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. Solubility NH 3 in water is extremely large - about 1200 volumes (at 0 °C) or 700 volumes (at 20 °C) in a volume of water. 3. Ammonia production In the laboratory In industry To obtain ammonia in the laboratory, the action of strong alkalis on ammonium salts is used: NH 4 Cl + NaOH = NH 3 + NaCl + H 2 O (NH 4 ) 2 SO 4 + Ca(OH) 2 = 2NH 3 + CaSO 4 + 2H 2 O Attention! Ammonium hydroxide is an unstable base, decomposes: NH 4 OH ↔ NH 3 + H 2 O When receiving ammonia, hold the receiver tube with the bottom up, since ammonia is lighter than air: The industrial method for producing ammonia is based on the direct interaction of hydrogen and nitrogen: N 2(g) + 3H 2(g) ↔ 2NH 3(g) + 45.9 kJ Conditions: catalyst – porous iron temperature – 450 – 500 ˚С pressure – 25 – 30 MPa This is the so-called Haber process (a German physicist who developed the physicochemical foundations of the method). 4. Chemical properties of 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) Reactions involving a change in the oxidation state of the nitrogen atom (oxidation reactions) N -3 → N 0 → N +2 NH 3 – a strong reducing agent. with oxygen 1. Ammonia combustion(when heated) 4NH 3 + 3O 2 → 2N 2 + 6H 2 0 2. Catalytic oxidation of ammonia (catalyst Pt – Rh, temperature) 4NH 3 + 5O 2 → 4NO + 6H 2 O with metal oxides 2 NH 3 + 3CuO = 3Cu + N 2 + 3 H 2 O with strong oxidizing agents 2NH3 + 3Cl2 = N2 + 6HCl (when heated) ammonia is a weak compound and decomposes when heated 2NH 3 ↔ N 2 + 3H 2 Reactions without changing the oxidation state of the nitrogen atom (addition - Formation of ammonium ion NH 4 + each donor-acceptor mechanism) 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 as an aqueous solution - ammonia water, which usually contains 25% NH 3 . Huge quantities of ammonia are then used to produce nitric acid, which is used to make fertilizers and many other products. Ammonia water is also used directly as a fertilizer, and sometimes fields are watered directly from tanks with liquid ammonia. Various ammonium salts, urea, and methenamine are obtained from ammonia. It is also used as a cheap refrigerant in industrial refrigeration units. Ammonia is also used to produce synthetic fibers, such as nylon and nylon. In light industry it is used in cleaning and dyeing cotton, wool and silk. In the petrochemical industry, ammonia is used to neutralize acidic 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 of 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. 3. Consolidation of the studied material No. 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 For ORR, compile an e-balance; for RIO, complete ionic equations. No. 2. Write four equations for the chemical reactions that produce ammonia. 4. Homework P. 24, ex. 2.3; test Ammonia- NH3, hydrogen nitride, under normal conditions - a colorless gas with a sharp characteristic odor (the smell of ammonia) This is the so-called Haber process (a German physicist who developed the physicochemical foundations of the method). The reaction occurs with the release of heat and a decrease in volume. Therefore, based on Le Chatelier's principle, the reaction should be carried out at the lowest possible temperatures and at high pressures - then the equilibrium will be shifted to the right. However, the reaction rate at low temperatures is negligible, and at high temperatures the rate of the reverse reaction increases. Carrying out the reaction at very high pressures requires the creation of special equipment that can withstand high pressure, and therefore large capital investments. In addition, the equilibrium of the reaction, even at 700 °C, is established too slowly for its practical use. The use of a catalyst (porous iron with Al2O3 and K2O impurities) made it possible to accelerate the achievement of an equilibrium state. Interestingly, when searching for a catalyst for this role, more than 20 thousand different substances were tried. Taking into account all the above factors, the process of producing ammonia is carried out under the following conditions: temperature 500 °C, pressure 350 atmospheres, catalyst. The yield of ammonia under such conditions is about 30%. In industrial conditions, the circulation principle is used - ammonia is removed by cooling, and unreacted nitrogen and hydrogen are returned to the synthesis column. This turns out to be more economical than achieving a higher reaction yield by increasing the pressure. To obtain ammonia in the laboratory, the action of strong alkalis on ammonium salts is used. Typically, ammonia is obtained in a laboratory method by gently heating a mixture of ammonium chloride and slaked lime. To dry ammonia, it is passed through a mixture of lime and caustic soda. Very dry ammonia can be obtained by dissolving sodium metal in it and subsequently distilling it. This is best done in a system made of metal under vacuum. The system must withstand high pressure (at room temperature, the pressure of saturated ammonia vapor is about 10 atmospheres). In industry, ammonia is dried in absorption columns. Consumption rates per ton of ammonia To produce one ton of ammonia in Russia, an average of 1200 nm³ of natural gas is consumed, in Europe - 900 nm³. Ammonia in medicine For insect bites, ammonia is used externally in the form of lotions. A 10% aqueous solution of ammonia is known as ammonia. Possible side effects: with prolonged exposure (inhalation use), ammonia can cause a reflex cessation of breathing. Local use is contraindicated for dermatitis, eczema, other skin diseases, as well as for open traumatic injuries to the skin. In case of accidental damage to the mucous membrane of the eye, rinse with water (15 minutes every 10 minutes) or 5% boric acid solution. Oils and ointments are not used. If the nose and throat are affected, use a 0.5% solution of citric acid or natural juices. If taken orally, drink water, fruit juice, milk, preferably a 0.5% solution of citric acid or a 1% solution of acetic acid until the contents of the stomach are completely neutralized. Interaction with other drugs is unknown. Interesting Facts Vapors from ammonia can change the color of flowers. For example, blue and blue petals turn green, bright red petals turn black.
Kr. dot	132.25 °C
Enthalpy of formation	-45.94 kJ/mol
Steam pressure	8.5 ± 0.1 atm
Chemical properties
pK a	9.21
Solubility in water	89.9 (at 0 °C)
Classification
Reg. CAS number
PubChem
Reg. EINECS number	231-635-3
SMILES
InChI
RTECS	BO0875000
ChEBI
UN number	1005
ChemSpider
Data are given for standard conditions (25 °C, 100 kPa), unless otherwise stated.

The use of a catalyst (porous iron with Al 2 O 3 and K 2 O impurities) made it possible to accelerate the achievement of an equilibrium state. Interestingly, when searching for a catalyst for this role, more than 20 thousand different substances were tried.

Taking into account all the above factors, the process of producing ammonia is carried out under the following conditions: temperature 500 °C, pressure 350 atmospheres, catalyst. The yield of ammonia under such conditions is about 30%. In industrial conditions, the circulation principle is used - ammonia is removed by cooling, and unreacted nitrogen and hydrogen are returned to the synthesis column. This turns out to be more economical than achieving a higher reaction yield by increasing the pressure.

To obtain ammonia in the laboratory, the action of strong alkalis on ammonium salts is used:

Typically, ammonia is obtained in a laboratory method by gently heating a mixture of ammonium chloride and slaked lime.

To dry ammonia, it is passed through a mixture of lime and caustic soda.

Very dry ammonia can be obtained by dissolving sodium metal in it and subsequently distilling it. This is best done in a system made of metal under vacuum. The system must withstand high pressure (at room temperature, the pressure of saturated ammonia vapor is about 10 atmospheres). In industry, ammonia is dried in absorption columns.

Consumption rates per ton of ammonia

To produce one ton of ammonia in Russia, an average of 1200 nm³ of natural gas is consumed, in Europe - 900 nm³.

The Belarusian Grodno Azot consumes 1200 nm³ of natural gas per ton of ammonia; after modernization, the consumption is expected to decrease to 876 nm³.

Ukrainian producers consume from 750 nm³ to 1170 nm³ of natural gas per ton of ammonia.

UHDE technology claims consumption of 6.7 - 7.4 Gcal of energy resources per ton of ammonia.

Ammonia in medicine

For insect bites, ammonia is used externally in the form of lotions. 10% aqueous ammonia solution is known as

Hydrogen, under normal conditions, is a colorless gas with a sharp characteristic odor (the smell of ammonia)

• Halogens (chlorine, iodine) form dangerous explosives with ammonia - nitrogen halides (nitrogen chloride, nitrogen iodide).

• Ammonia reacts with halogenated alkanes through nucleophilic addition, forming a substituted ammonium ion (method for producing amines):

• It produces amides with carboxylic acids, their anhydrides, acid halides, esters and other derivatives. With aldehydes and ketones - Schiff bases, which can be reduced to the corresponding amines (reductive amination).

• At 1000 °C, ammonia reacts with coal, forming hydrocyanic acid HCN and partially decomposing into nitrogen and hydrogen. It can also react with methane, forming the same hydrocyanic acid:

History of the name

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 Amun. During their rituals, they sniffed ammonia NH 4 Cl, which, when heated, evaporates ammonia.

Liquid ammonia

Liquid ammonia, although to a small extent, dissociates into ions (autoprotolysis), which shows its similarity to water:

The self-ionization constant of liquid ammonia at −50 °C is approximately 10 −33 (mol/l)².

The metal amides resulting from the reaction with ammonia contain a negative ion NH 2 −, which is also formed during the self-ionization of ammonia. Thus, metal amides are analogues of hydroxides. The reaction rate increases when going from Li to Cs. The reaction is significantly accelerated in the presence of even small impurities of H 2 O.

Metal-ammonia solutions have metallic electrical conductivity; in them, metal atoms decompose into positive ions and solvated electrons surrounded by NH 3 molecules. Metal-ammonia solutions, which contain free electrons, are the strongest reducing agents.

Complexation

Due to their electron-donating properties, NH 3 molecules can enter complex compounds as ligands. Thus, the introduction of excess ammonia into solutions of d-metal salts leads to the formation of their amino complexes:

Complexation is usually accompanied by a change in the color of the solution. So, in the first reaction, the blue color (CuSO 4) turns into dark blue (the color of the complex), and in the second reaction the color changes from green (Ni(NO 3) 2) to blue-violet. The strongest complexes with NH 3 are formed by chromium and cobalt in the oxidation state +3.

Biological role

Ammonia is the end product of nitrogen metabolism in the body of humans and animals. It is formed during the metabolism of proteins, amino acids and other nitrogenous compounds. It is highly toxic to the body, so most of the ammonia during the ornithine cycle is converted by the liver into a more harmless and less toxic compound - carbamide (urea). The urea is then excreted by the kidneys, and some of the urea may be converted by the liver or kidneys back to ammonia.

Ammonia can also be used by the liver for the reverse process - resynthesis of amino acids from ammonia and keto analogues of amino acids. This process is called "reductive amination". Thus, aspartic acid is obtained from oxaloacetic acid, glutamic acid is obtained from α-ketoglutaric acid, etc.

Physiological action

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 has both local and resorptive effects.

Ammonia vapors strongly irritate the mucous membranes of the eyes and respiratory organs, as well as the skin. This is what a person perceives 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. When liquefied ammonia and its solutions come into contact with the skin, a burning sensation occurs, and a chemical burn with blisters and ulcerations is possible. In addition, liquefied ammonia absorbs heat when it evaporates, and when it comes into contact with the skin, frostbite of varying degrees occurs. The smell of ammonia is felt at a concentration of 37 mg/m³.

Application

Ammonia is one of the most important products of the chemical industry; its annual global production reaches 150 million tons. Mainly used for the production of nitrogen fertilizers (ammonium nitrate and sulfate, urea), explosives and polymers, nitric acid, soda (using the ammonia method) and other chemical industry products. Liquid ammonia is used as a solvent.

Consumption rates per ton of ammonia

To produce one ton of ammonia in Russia, an average of 1200 nm³ of natural gas is consumed, in Europe - 900 nm³.

The Belarusian Grodno Azot consumes 1,200 nm³ of natural gas per ton of ammonia; after modernization, the consumption is expected to decrease to 876 nm³.

Ukrainian producers consume from 750 nm³ to 1170 nm³ of natural gas per ton of ammonia.

UHDE technology claims consumption of 6.7 - 7.4 Gcal of energy resources per ton of ammonia.

Ammonia in medicine

For insect bites, ammonia is used externally in the form of lotions. A 10% aqueous solution of ammonia is known as ammonia.

Possible side effects: with prolonged exposure (inhalation use), ammonia can cause a reflex cessation of breathing.

Local use is contraindicated for dermatitis, eczema, other skin diseases, as well as for open traumatic injuries to the skin.

In case of accidental damage to the mucous membrane of the eye, rinse with water (15 minutes every 10 minutes) or 5% boric acid solution. Oils and ointments are not used. If the nose and throat are affected, use a 0.5% solution of citric acid or natural juices. If taken orally, drink water, fruit juice, milk, preferably a 0.5% solution of citric acid or a 1% solution of acetic acid until the contents of the stomach are completely neutralized.

Interaction with other drugs is unknown.

Ammonia producers

Ammonia producers in Russia

Russia accounts for about 9% of global ammonia production. Russia is one of the world's largest exporters of ammonia. About 25% of total ammonia production is exported, which is about 16% of world exports.

Ammonia producers in Ukraine

• Jupiter's clouds are made of ammonia.

see also

Notes

Links

• //
• // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional ones). - St. Petersburg. , 1890-1907.
• // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional ones). - St. Petersburg. , 1890-1907.
• // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional ones). - St. Petersburg. , 1890-1907.

Literature

• Akhmetov N. S. General and inorganic chemistry. - M.: Higher School, 2001.