What particles are present in liquid ammonia. Ammonia in forensic medicine. Ammonia for cockroaches and ants

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.

Ammonia is a gaseous substance with a strong, unpleasant odor. What properties does it have and what substances does it react with?

Molecule structure

The electronic formula of ammonia is as follows:

Rice. 1. Electronic formula of ammonia.

Of the four electron pairs at the nitrogen atom, three are shared and one is lone. The formation of the NH 3 molecule involves three unpaired p-electrons of the nitrogen atom, the electron orbitals of which are mutually perpendicular, and the 1s electrons of three hydrogen atoms. The molecule has the shape of a regular pyramid: in the corners of the triangle there are hydrogen atoms, and at the top of the pyramid there is a nitrogen atom. The angle between the H-N-H bonds is 107.78 degrees.

Physical properties

Ammonia is a colorless gas with a characteristic pungent odor. The boiling point of ammonia is -33.4 degrees Celsius, the melting point is -77.8 degrees.

Ammonia is highly soluble in water (at 20 degrees, up to 700 volumes of ammonia dissolve in 1 volume of water). The concentrated solution has an ammonia density of 0.91 g/cm3.

A solution of ammonia in water is called ammonia water or ammonia. When boiling, dissolved ammonia evaporates from the solution.

Rice. 2. Ammonia.

Ammonia is somewhat less soluble in organic solvents (alcohol, acetone, chloroform, benzene). Ammonia dissolves many nitrogen-containing substances well.

Liquid ammonia has a high heat of evaporation (at -50 degrees 145 kJ/kg, at 0 degrees 1260 kJ/kg, at 50 degrees 1056 kJ/kg).

The molar mass and molecular weight of ammonia is 17

Chemical properties

Chemically, ammonia is quite active. reactions in which ammonia participates are accompanied either by a change in the oxidation state of nitrogen or by the formation of a special type of covalent bond. The high solubility of a chemical substance in water is due to the formation of hydrogen bonds between their molecules.

Ammonia can react with the following substances:

• When interacting with acids, ammonia neutralizes them, thereby forming ammonium salts:

NH 3 +HCl=NH 4 Cl

• When reacting with halogens, ammonia is usually oxidized to free nitrogen:

8NH 3 +3Br 2 =N 2 +6NH 4 Br

• When mixed with oxygen, ammonia burns with a greenish-yellow flame:

4NH 3 +3O 2 =6H 2 O+2N 2

• when heated, ammonia reduces copper (II) oxide, and itself is oxidized to free nitrogen:

3CuO+2NH 3 =3Cu+N 2 +3H 2 O

– using this reaction you can obtain oxygen in the laboratory.

Receipt and use

In the laboratory, ammonia is obtained by heating ammonium chloride NH 4 Cl with slaked lime Ca (OH) 2:

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

– the released ammonia contains water vapor.

In industry, ammonia is produced from nitrogen and hydrogen. The reaction of ammonia synthesis proceeds with the release of heat and a decrease in volume:

N 2 +3H 2 =2NH 3

The temperature required for ammonia synthesis is achieved by preheating the nitrogen-hydrogen mixture and by releasing reaction heat. The catalyst for ammonia synthesis is sponge iron activated by certain metals. Hydrogen sulfide, oxygen, carbon oxide and dioxide, vapors and other mixtures contained in the nitrogen-hydrogen mixture sharply reduce the activity of the catalyst. Synthesis is carried out at a temperature of 500-550 degrees and a pressure from 15 to 100 MPa.

The ammonia synthesis plant diagram looks like this:

Rice. 3. Scheme of ammonia production.

Most of the ammonia synthesized in industry is used to produce nitric acid and other nitrogen-containing substances. Its use in refrigeration units is based on easy liquefaction and subsequent evaporation with heat absorption.

Aqueous solutions of ammonia are used in chemical laboratories and industries as a weak, highly volatile base. Aqueous solutions are also used in medicine and everyday life.

What have we learned?

The study of ammonia is included in the compulsory school chemistry course. Ammonia is a chemical compound that contains nitrogen and hydrogen. The gas is a colorless substance with a pronounced odor and reacts with acids, water, halogens, oxygen and other complex and simple substances.

Test on the topic

Evaluation of the report

Average rating: 4.7. Total ratings received: 143.

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.

In everyday life, ammonia is often used, but they call it both ammonia and ammonia, remaining in full confidence that they are the same thing.

In fact, these are different substances that differ from each other in their origin, state of aggregation and chemical formulas. The only thing that brings these three different substances together is the sharp ammonia smell.

The smell is the same, but the substances are different

In order to be convinced once and for all that ammonia and ammonia are the same thing, it is enough to turn to the history of their origin and look at their chemical formulas.

Ammonia is hydrogen nitride, a gas with a molar mass of 17 g/mol, chemical formula - NH3.

Ammonia or ammonia alcohol is a liquid with the chemical formula NH4OH.

Ammonia is a salt with the chemical formula - NH4Cl.

Origin of ammonia

The history of the discovery of natural ammonia gas has two legends. According to the first legend, near the temple of the Egyptian god Amon, where religious rites were performed, people sniffed a pair of camel excrement, which caused them to fall into a trance. These vapors were called "ammonia".

According to the second legend, in northern Africa, in the area of ​​​​the Ammon oasis, there was an intersection of caravan routes. A huge number of animals passed there, the road was strewn with their feces and abundantly watered with urine, which evaporated and released a gas called “ammonia”.

As for the scientific discovery of a gas called “ammonia,” it dates back to 1785. The chemical formula of the gas, NH3, was determined by the French scientist C. L. Berthollet and named it “ammonia.”

But back in 1774, the English scientist D. Priestley obtained an identical gas, which he gave the name “alkaline air,” but could not determine the chemical composition.

Ammonia (ammonia in Latin) is a colorless gas with a specific odor, lighter than air, chemically active, liquefied at a temperature of -33 C; dissolves well in water, has an alkaline reaction; interacts with hydrochloric acid and forms an ammonium salt: NH3 + HCl = NH4Cl, which decomposes when heated: NH4Cl = NH3 + HCl.

Ammonia is produced in two ways - industrial and laboratory. In the laboratory method, ammonia is obtained by heating alkalis and ammonium salts:

• NH4Cl + KOH = NH3 + KCl + H2O;
• NH4 + + OH - = NH 3 + H2O.

In industrial settings, ammonia is first produced in gaseous form and then liquefied into a 25% aqueous solution called ammonia water.

Ammonia synthesis is a very important chemical production, since ammonia is a fundamental element for many other chemical technologies and industries. Thus, ammonia is used in industrial refrigeration units as a refrigerant; is a bleaching agent for processing and dyeing fabrics; indispensable in the production of nitric acid, nitrogen fertilizers, ammonium salts, synthetic fibers - nylon and nylon.

The industrial method for the synthesis of ammonia was invented in 1909 by the German chemist Fritz Haber. In 1918, he received the Nobel Prize for his discoveries in chemistry. The first ammonia production plant was launched in 1913 in Germany, and in 1928 ammonia production was already established in Russia.

Origin of ammonia

Ammonia (Hammoniaci P. Sal) is a salt with the chemical formula NH4Cl (ammonium chloride).

Ammonia is of volcanic origin; found in hot springs, groundwater evaporation, guano and native sulfur deposits; formed when coal seams or debris accumulations burn. It has the appearance of deposits, earthy deposits, crusts or massive skeletal crystalline accumulations, clusters and dendrites.

Pure ammonia is colorless or white, with a glassy sheen. Depending on the impurities present in it, the color can be all shades of yellow, brown, gray, different shades of red, brown.

When heated, ammonia is released from ammonia; it dissolves well in water. The solution has a burning, acrid, salty taste and a pungent ammonia smell.

Ammonia has been known to people since ancient times and was used in ritual ceremonies, in the production and dyeing of fabrics, as well as by alchemists for soldering metals and alloying gold.

In the Middle Ages, they learned to obtain artificial ammonia from the horns and hooves of cattle, which was called the “deer antler spirit.”

Origin of ammonia

Liquor ammonia caustici is its Latin name.

This is a 10% ammonia water solution with the chemical formula NH4OH; colorless transparent homogeneous mixture capable of evaporation; with a specific odor of ammonia, which persists when frozen.

The mention of its use by Eastern alchemists dates back to the 8th century, and by European alchemists to the 13th century. Their notes on the recipes they used have survived to this day.

Nowadays, they are obtained industrially and in simple household ways:

• industrially, synthesis is carried out from the gaseous state of hydrogen, nitrogen and air using certain catalysts, and then an aqueous-alcohol solution is obtained, which has a pungent ammonia odor;
• a simple household method is based on diluting 25% ammonia water to a 10% solution.

Areas of use

The scope of application of ammonia and ammonia alcohol is wide; it is used in almost all spheres of human activity, from technological processes to medicine and household needs.

Application of ammonia

Ammonia is widely used as a refrigerant in various household and industrial equipment.

It is one of the most important products used in the chemical industry . In particular, it is used in production:

• ammonia;
• additives in building materials for use in frosty conditions;
• polymers, soda and nitric acid;
• fertilizers;
• explosives.

Using ammonia alcohol

Ammonia alcohol is used in medicine and in everyday life.

Medical use is indicated in the following cases:

Use in everyday life is to degrease and clean various household utensils.

Alcohol solution at the rate of 2 tsp. for 2 glasses of water and 1 tbsp. l. Any dishwashing detergent can perfectly clean silverware, silver and gold jewelry (items with pearls cannot be cleaned with ammonia, it will become gray and cloudy). To do this, place silverware or jewelry in the solution, hold for 1 to 2 hours, then rinse in water and wipe dry.

It removes blood, urine and sweat stains from wool, silk and lycra well. A 50% solution is used as a stain remover. In concentrated form, it can remove pencil marks on clothes.

From carpets, furniture upholstery and car covers, you can remove heels with a solution of 1 tbsp. l. pure ammonia and 2 liters of hot water. To do this, you need to clean the dirt and let it dry. If necessary, you can clean it again.

Window glass, mirrors and earthenware can also be cleaned with a solution of 1 tbsp. l. pure ammonia and 3 tbsp. water. The surface will be clean and shiny.

Ammonia water 1 tbsp. l. mixed with 4 liters of water, you can clean off stone deposits in the bathtub and washbasin. To do this, you need to clean them with a solution and then rinse them with hot water.

Alcohol can be used in gardening to combat onion flies and aphids, and also as a fertilizer for garden and indoor plants in acidic soil conditions.

Impact on humans

When using ammonia and ammonia, you must remember: that these are highly toxic substances and when using them, the dosage should be strictly observed and adhere to the rules of use.

If you intend to use ammonia, you must purchase it exclusively in pharmacies and carefully read the attached instructions for use “Ammonia solution. Instructions for use."

Exceeding dosages can cause poisoning and serious health problems, as well as chemical burns. The rooms where it is used must be well ventilated.

In addition to being toxic, ammonia vapors are explosive. This occurs when they are mixed with air in a certain proportion, so when working it is necessary to follow special safety rules when working with explosives.

The first symptoms of poisoning may be:

• the appearance of red spots on the face and body;
• rapid breathing;
• general excitement.

Further signs of poisoning development are:

• the appearance of acute pain in the chest;
• convulsions;
• swelling of the larynx;
• spasm of the vocal cords;
• muscle weakness;
• circulatory disorders;
• semi-fainting state, up to loss of consciousness.

When ingesting ammonia water in excess doses, the following may occur:

• diarrhea with false painful urges; burn of the esophagus, stomach and initial parts of the intestines;
• cough, watery eyes, drooling, and sneezing;
• reflex cessation of breathing;
• vomiting with the smell of ammonia;
• taking ammonia alcohol in an amount of 10 to 15 g. threatens death.

If a person has an individual intolerance to the smell of ammonia, then even a slight ingestion of it through the respiratory tract or inside can immediately lead to the most unfavorable consequences.

If a person has a skin disorder on the body in the form of weeping ulcers, eczema or dermatitis, then the use of lotions can lead to an even more extensive allergic reaction and burns of the skin.

First aid for poisoning

If the first signs of poisoning by these substances occur, it is necessary to immediately begin providing first aid to the victim.

First aid measures include the following:

In case of more severe forms of poisoning, it is necessary to urgently call an ambulance.

Ammonia alcohol is required in first aid kits in first aid kits and should be on hand at the right time.

How much can it cost in pharmacies? The answer is very inexpensive. Buy it, use it, but be extremely careful.

Attention, TODAY only!

DEFINITION

Ammonia- hydrogen nitride.

Formula – NH 3. Molar mass – 17 g/mol.

Physical properties of ammonia

Ammonia (NH 3) is a colorless gas with a pungent odor (the smell of “ammonia”), lighter than air, highly soluble in water (one volume of water will dissolve up to 700 volumes of ammonia). The concentrated ammonia solution contains 25% (mass) ammonia and has a density of 0.91 g/cm 3 .

The bonds between atoms in the ammonia molecule are covalent. General view of the AB 3 molecule. All valence orbitals of the nitrogen atom enter into hybridization, therefore, the type of hybridization of the ammonia molecule is sp 3. Ammonia has a geometric structure of the AB 3 E type - a trigonal pyramid (Fig. 1).

Rice. 1. The structure of the ammonia molecule.

Chemical properties of ammonia

Chemically, ammonia is quite active: it reacts with many substances. The oxidation degree of nitrogen in ammonia “-3” is minimal, so ammonia exhibits only reducing properties.

When ammonia is heated with halogens, heavy metal oxides and oxygen, nitrogen is formed:

2NH 3 + 3Br 2 = N 2 + 6HBr

2NH 3 + 3CuO = 3Cu + N 2 + 3H 2 O

4NH 3 +3O 2 = 2N 2 + 6H 2 O

In the presence of a catalyst, ammonia can be oxidized to nitrogen oxide (II):

4NH 3 + 5O 2 = 4NO + 6H 2 O (catalyst - platinum)

Unlike hydrogen compounds of non-metals of groups VI and VII, ammonia does not exhibit acidic properties. However, hydrogen atoms in its molecule are still capable of being replaced by metal atoms. When hydrogen is completely replaced by a metal, compounds called nitrides are formed, which can also be obtained by direct interaction of nitrogen with the metal at high temperatures.

The main properties of ammonia are due to the presence of a lone pair of electrons on the nitrogen atom. A solution of ammonia in water is alkaline:

NH 3 + H 2 O ↔ NH 4 OH ↔ NH 4 + + OH —

When ammonia interacts with acids, ammonium salts are formed, which decompose when heated:

NH 3 + HCl = NH 4 Cl

NH 4 Cl = NH 3 + HCl (when heated)

Ammonia production

There are industrial and laboratory methods for producing ammonia. In the laboratory, ammonia is obtained by the action of alkalis on solutions of ammonium salts when heated:

NH 4 Cl + KOH = NH 3 + KCl + H 2 O

NH 4 + + OH - = NH 3 + H 2 O

This reaction is qualitative for ammonium ions.

Application of ammonia

Ammonia production is one of the most important technological processes worldwide. About 100 million tons of ammonia are produced annually in the world. Ammonia is released in liquid form or in the form of a 25% aqueous solution - ammonia water. The main areas of use of ammonia are the production of nitric acid (subsequent production of nitrogen-containing mineral fertilizers), ammonium salts, urea, hexamine, synthetic fibers (nylon and nylon). Ammonia is used as a refrigerant in industrial refrigeration units and as a bleaching agent in the cleaning and dyeing of cotton, wool and silk.

Examples of problem solving

EXAMPLE 1