Ammonia presentation. Presentation on the theme "ammonia" Ammonia presentation

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Lesson topic: Ammonia “You can not love chemistry, but you cannot live without it today and tomorrow” О.М. Nefedov

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We meet with ammonia HNO3 production Medicine A product of protein metabolism in living organisms Fertilizer production Detergents Hair dye Coolant in refrigerators Today, ammonia is of exceptional importance as a raw material for the production of nitrogen-containing substances used in agriculture, chemistry, medicine, and military affairs. And what is no less important, it is one of the products of protein metabolism in the body.

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The story of the discovery of ammonia In the middle of the Libyan desert there was a temple dedicated to the god Amon Ra. In ancient times, Arab alchemists obtained colorless crystals from the Amon oasis, which was located near the temple. grinded in mortars, heated - and got a caustic gas. At first it was called ammonia, and then the name was shortened to "ammonia". In the 18th century, ammonia was obtained by the English chemist Joseph Priestley. Today, ammonia is of exceptional importance as a raw material for the production of nitrogen-containing substances used in agriculture, chemistry, medicine, and military affairs. And what is no less important, it is one of the products of protein metabolism in the body.

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Physical properties of ammonia NH3 NH3 Ammonia is a gas: colorless, with a characteristic odor, lighter than air (collected in a vessel turned upside down) NH3 - POISONOUS! Liquid ammonia causes severe skin burns; usually it is transported in steel cylinders (painted yellow, marked "Ammonia" in black) Ammonia - 3-10% ammonia solution Ammonia water - 18 -25% ammonia solution A mixture of ammonia with air is explosive!

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The structure of the ammonia molecule ▪ ▪ ▪ H * * * H H │ N ▪ with atoms having a vacant (free) orbital according to the donor-acceptor mechanism. Valence N is equal to IV Donor-acceptor bond mechanism: H3N: + H + = + ammonium ion

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Chemical properties of ammonia Reactions involving a change in the oxidation state of nitrogen NH3 - a strong reducing agent without a change in the oxidation state of nitrogen NH3 - a weak base 1.ammonia is a fragile compound, decomposes when heated: 2NH3 N2 + 3H2 2.Ammonia burns in oxygen: NH3 + O2 → N2 + H2O 3.oxidation of ammonia with atmospheric oxygen in the presence of a catalyst: NH3 + O2 NO + H2O Pt, Rh ammonia reacts with water: NH3 + H2O NH4OH NH4 + + OH− ammonium hydroxide ammonia reacts with acids: NH3 + HCl → NH4Cl ammonium chloride

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Good old ammonia, He is a rich man, and he is a poor man, Rich in his unshared electrons, But only, here's the problem, he is bored alone in the solution. He is always ready to take a walk: There is acid, and here is water ... Then, stripped to the skin, He cries: “Where are my belongings? What a lawlessness: I have become an ammonium cation! "

Ammonia: composition, structure, properties, application

Lukusha Elena Fedorovna, teacher of chemistry MBOU "Marine secondary school" of the urban district of Sudak, Republic of Crimea

Ammonia may owe its name to the oasis of the god Ammon in North Africa, located at the crossroads of caravan routes.

In very hot climates, urea (NH 2) 2 CO decomposes especially quickly.

One of the main decomposition products is ammonia.

Oasis "Ammon"

in North Africa

According to some other information, ammonia could get its modern name from the ancient Egyptian word "amonian".

So they called everyone

believing people worshiping the god Amon.

During their ritual ceremonies, people smelled NH 4 Cl, which, when heated, emits the smell of ammonia.

God Ammon in the form of a ram

The abbreviated name "ammonia", which we always use, was introduced into use in 1801 by a Russian scientist - chemist, academician

Yakov Dmitrievich Zakharov, who was also the first to develop the system of Russian chemical nomenclature.

covalent polar

Chemical bond

Crystal cell

molecular

Physical properties (under normal conditions)

• colorless gas

with a pungent characteristic odor (the smell of ammonia)

• lighter than air (M = 17 g / mol)
• well soluble in water (1200 volumes at 0 ° C) and 700 volumes (at 20 ° C) in a volume of water
• melting temperature -77.73 ° C
• boiling temperature -33.34 ° C

• POISONOUS!

Ammonia production

For the production of ammonia in the laboratory use the action of strong alkalis on ammonium salts:

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

(NH 4 ) 2 SO 4 + 2NaOH = 2NH 3 + Na 2 SO 4 + 2H 2 O

Ammonium hydroxide is an unstable base, decomposes:

NH 4 OH ↔ NH 3 + H 2 O

When receiving ammonia, it is necessary to hold the test tube - the receiver upside down, since ammonia ... ..

Industrial method for producing ammonia based on the direct interaction of hydrogen and nitrogen:

N2 (g) + 3H2 (g) ↔ 2NH3 (g) + 45.9 kJ

catalyst - porous iron

temperature - 450 - 500 ˚С

pressure - 25 - 30 MPa

This is the so-called Haber process (a German physicist who developed the physical and chemical foundations of the method).

Chemical properties of ammonia

Ammonia is characterized by 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 with a change in the oxidation state of the nitrogen atom (oxidation reactions)

N -3 → N 0 → N +2

NH3-strong reducing agent

with oxygen

Combustion of ammonia (when heated)

4NH 3 + 3O 2 → 2N 2 + 6H 2 0

Catalytic oxidation of amiak (Pt - Rh catalyst, temperature)

4NH 3 + 5O 2 → 4NO + 6H 2 O

with metal oxides

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

with strong oxidants

2NH 3 + 3Cl 2 = N 2 + 6HCl

(when heated)

Reactions without changing the oxidation state of the nitrogen atom (addition - the formation of an ammonium ion NH 4 +

by donor-acceptor mechanism

5interaction with acids

NH 3 + HCl → NH 4 Cl

2NH 3 + H 2 SO 4 → (NH 4 ) 2 SO 4

Interaction with water

NH 3 + H 2 O = NH 4 OH

When phenolphthalein is added, the solution becomes raspberry-colored, since when ammonia dissolves, ammonium hydroxide NH 4 OH is partially formed.

Ammonia application

• Plastics and

fibers

2. As part of detergents

3. Production of nitrogen fertilizers

4. In agriculture

5. Production of nitric acid

6. Obtaining explosives

It is interesting

• Vapors of ammonia can change the color of flowers. For example, blue and blue petals become green , bright red - black.

• Jupiter's clouds are composed of ammonia.

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I will tell myself, friends, I'm never afraid No dictation, No test, No poetry and no tasks, No problems, no failures. I am calm, patient, I am restrained And not gloomy.

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Ammonia may also owe its name to the oasis of the god Ammon in North Africa, located at the crossroads of caravan routes. In very hot climates, urea (NH2) 2CO decomposes especially quickly. One of the main decomposition products is ammonia. Origin of the name Ammon Oasis in North Africa NH3

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According to some other information, ammonia could get its modern name from the ancient Egyptian word "amonian". So called all believers who worship the god Amon. During their ritual ceremonies, people sniffed NH4Cl, which, when heated, emits the smell of ammonia. God Amon in the form of a ram of the 8th century BC. (Meroe Museum, Sudan) NH3 Origin of the name

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The abbreviated name "ammonia" which we always use, was introduced in 1801 by the Russian chemist and academician Yakov Dmitrievich Zakharov, who was the first to also develop the system of Russian chemical nomenclature. 1781-1852 NH3 Origin of the name

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History of the discovery of ammonia Ammonia was obtained in its pure form in 1774 by the English chemist Joseph Louis Priestley. He heated ammonia (ammonium chloride) with slaked lime (calcium hydroxide). 1711-1794 Priestley called the gas "alkaline air or volatile alkali" because the aqueous ammonia solution had all the characteristics of alkali. NH3

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1723-1802 NH3 In 1784 the French chemist Berthollet proved its elemental composition by decomposition of ammonia, which in 1787 received the official name "ammonia" - from the Latin name for ammonia - salammoniac. This name is preserved to this day in most Western European languages ​​(German Ammonium chloride, English Ammonia, French ammoniaque). The history of the discovery of ammonia

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The structure of the nitrogen atom N Nitrogen 14.0067 2 5 7 2s22p3 N 2s 2p NH3 Thus, the nitrogen atom has 3 unpaired electrons on the last (2 p) orbital. The electronic formula is: 1S2 2S2 2P3 + 7N)) 2 5

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The nitrogen atom is in a state of sp3 hybridization. 109028 ': N + H: N: H H H H:: H       107.30  There is a lone pair of electrons in the 4th hybridized p orbital of the N atom. The shape of the molecule is pyramidal. Н:: Н NH3 Nitrogen with hydrogen forms 3 covalent bonds by the exchange mechanism Formation of a molecule

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N-H bonds are polar, common electron pairs are displaced towards the nitrogen atom as an atom with a higher EO. EO (H) = 2.1 EO (N) = 3.5. The molecule is polar. NH3 Nitrogen with hydrogen forms 3 covalent bonds by the exchange mechanism

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Hydrogen bonds increase the boiling and melting points. Hydrogen bonds are formed between ammonia molecules, that is, ammonia is associated in a liquid state. NH3

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NH3 R - high 1V: 700V, C Tboil = - 33.4 C Tm = - 77.7 C 0 0 Gas, 1.7 times lighter than air H2O NH3 NH3 Physical properties Pungent odor. TOXIC Molecular crystal lattice

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In industry: N2 + 3H2 2NH3 + 45.9 kJ NH3 N2 + 3H2 ↔ 2NH3 Fe, t, p mixture of nitrogen and hydrogen turbocompressor catalyst heat exchanger refrigerator separator NH3 Production methods

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In the laboratory: 1. By the action of alkalis on ammonium salts: 2. Hydrolysis of nitrides: 2NH4Cl + Ca (OH) 2 = CaCl2 + 2NH3 + 2H2O Ammonium + slaked lime t Mg3N2 + 6H2O = 3Mg (OH) 2 + 2NH3 NH3

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NH3 is the lowest oxidation state of nitrogen. -3 Ammonia - reducing agent 2. Basic properties (lone pair of electrons) 3. Specific properties of NH3 Chemical properties

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NH3 Reaction of ammonia combustion (up to N2): 4NH3 + 3O2 = 2N2 + 6H2O = Ammonia reductant

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NH3 Catalytic oxidation of ammonia (to NO): 4NH3 + 5O2 = 4NO + 6H2O Ammonia reducer

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Some inactive metals can be reduced with ammonia: 3CuO + 2 NH3 = 3Cu + N2 + 3H2O Ammonia decolours potassium permanganate: 2KMnO4 + 2 NH3 = 2 KOH + N2 + 2H2O + 2MnO2 Ammonia decolorizes bromine water: 3Br2 + 8NHN2 K Colour

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Ammonia reacts with water, forming ammonia hydrate (ammonia water): NH3 + H2O = NH4OH Changes the color of indicators: Phenolphthalein - b / color raaline Litmus becomes  blue NH3 Ammonium hydroxide exhibits all the properties of alkalis !!! Main properties Interaction with water

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NH3 + HCl → NH4Cl ammonium chloride (ammonia) 2 NH3 + H2SO4 → (NH4) 2SO4 ammonium sulfate Interaction with acids NH3 Smoke without fire ?! (Formed by the formation of ammonium chloride) Basic properties

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Reaction mechanism Ionic bond in ammonium salts !!! NH3

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Three bonds are formed by the exchange mechanism, the fourth - by the donor-acceptor one. Donor - a molecule or ion with a free pair of electrons. Acceptor - a molecule or ion with a free orbital. N H H H H + N H H H H + ACCEPTOR DONOR Formation of ammonium ion NH3 +

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NH3 Specific properties 1. Interaction with sodium hypochlorite (hydrazine formation): 2NH3 + NaClO = N2H4 + NaCl + H2O Hydrazine is used to obtain rocket fuel

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NH3 Specific properties 2. Interaction with active metals (formation of amides): 2NH3 + 2K = 2KNH2 + H2

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3. Interaction with organic substances (formation of amines): NH3 + CH3Cl → CH3NH2 + HCl Specific properties of NH3

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NH3 4. Complexation: CuSO4 + 4NH3 → SO4 Cu (OH) 2+ 4NH3 → (OH) 2 Specific properties Due to their electron-donating properties, NH3 molecules can enter complex compounds as a ligand.

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Generalization

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Nitric acid Ammonium sulfate (NH4) 2SO4 Ammonium chloride NH4Cl Carbamide (urea) CO (NH2) 2 Ammonia Fertilizers Medicines (medicine) Rocket fuel oxidizer Ammonium salts for brazing Explosives production Soda production Refrigeration plants Precious metal processing NH3 Ammonia use

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NH3 Man-made disasters

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NH3 1. Do not touch the spilled substance, it may cause painful skin burns. 2. In case of ammonia poisoning, do not drink, but you need to drip albucide into your eyes or rinse your eyes with a solution of boric acid. 3. In the nose, drip warm sunflower, olive or peach oil, and rinse the face, hands and generally the affected areas of the body with a 2% solution of boric acid. The maximum concentration limit for ammonia is 0.001 mg / l. Ammonia poisoning

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Solve the problems: Level A: How much ammonia can be obtained by heating 7.4 g of calcium hydroxide with ammonium chloride ?. Level B: Ammonia with a volume of 4.48 L (NU) was burned in an equal volume of oxygen. Determine the mass of the nitrogen obtained. Level C: Ammonia with a volume of 2.24 L (NU) was passed into a solution of phosphoric acid with a mass of 100 g with a mass fraction of acid of 19.8%. Determine the composition of the salt and its mass fraction in the resulting solution. NH3 Exam Preparation

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Crossword Vertically: 1. The Latin name for nitrogen ... Horizontally: 2. The name of explosives derived from ammonium salts ... 3. The scientist who first obtained pure ammonia ... 4. The product of the interaction of ammonia with acid is ... 5. Ammonia and its aqueous solution are weak ... 6. The name of a 10% ammonia solution is ammonia ... 7. Ammonia in reactions with water and acids forms an ion ... NH3

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Sinkwine NH3 Ammonia Gaseous Water-soluble Reducing agent during oxidation Salt-forming ammonia Infects mucous membranes Nourishes plants

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Thank you for attention

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HISTORICAL SUMMARY Ammonia was first obtained in pure form in 1774 by the English chemist Joseph Priestley. In 1784, the French chemist Claude Louis Berthollet, using an electric discharge, decomposed ammonia into elements and thus established the composition of this gas, which in 1787 received the official name "ammonia" - from the Latin name for ammonia - sal ammoniac; this salt was obtained near the temple of the god Amun in Egypt. Joseph Priestley Claude Louis Berthollet

HISTORICAL SUMMARY This name is retained today in most Western European languages ​​(German Ammoniak, English ammonia, French ammoniaque); The abbreviated name "ammonia" that we use was introduced in 1801 by the Russian chemist Yakov Dmitrievich Zakharov, who was the first to develop the system of Russian chemical nomenclature. Ammon Oasis in North Africa Remains of the Temple of Ammon

The pungent smell of ammonia has been known to man since prehistoric times, since this gas is formed in significant quantities during the decay, decomposition and dry distillation of nitrogen-containing organic compounds, such as urea or proteins. It is possible that in the early stages of the Earth's evolution, there was quite a lot of ammonia in its atmosphere. However, even today, trace amounts of this gas can always be found in the air and in rainwater, since it is continuously formed during the decomposition of animal and plant proteins. On some planets of the solar system, the situation is different: astronomers believe that a significant part of the masses of Jupiter and Saturn falls on solid ammonia. HISTORICAL REFERENCE

STRUCTURE OF THE AMMONIA MOLECULE Nitrogen is a more electronegative element than hydrogen; therefore, when an N-H bond is formed, the common electron pairs are "shifted" to the nitrogen atom. Each N-H bond becomes polar, and therefore the ammonia molecule as a whole is polar. Another thing is seen from the electronic formula: the nitrogen atom has a free (lonely) pair of electrons. This further increases the polarity of the ammonia molecule and gives rise to many of the properties of ammonia.

PHYSICAL PROPERTIES OF AMMONIA colorless gas has a pungent odor pungent taste 1.7 times lighter than air at T = -33.4 0 C liquefies at T = -77.7 0 C solidifies dissolves in alcohols, benzene, acetone, readily soluble in water ( in 1 V water - 700 V ammonia) Solubility of ammonia in water Н2ОН2О NH3

PHYSIOLOGICAL EFFECTS ON THE HUMAN ORGANISM According to the physiological effect on the body, it belongs to the group of substances of asphyxiation and neurotropic action, capable of causing toxic pulmonary edema and severe damage to the nervous system in case of inhalation damage. 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 smell. Ammonia vapors cause profuse lacrimation, eye pain, chemical burns of the conjunctiva and cornea, loss of vision, coughing fits, redness and itching of the skin. When liquefied ammonia and its solutions come into contact with the skin, a burning sensation occurs, a chemical burn with blisters, ulceration is possible. In addition, liquefied ammonia absorbs heat when it evaporates, and frostbite of varying degrees occurs on contact with the skin.

CHEMICAL PROPERTIES OF AMMONIA (associated with changes in the oxidation state of nitrogen) 1. Decomposition of ammonia:? N -3 H 3 + = N? H Combustion of ammonia:? N -3 H? О 2 0 =? N? H 2 O -2 + Q 3. Catalytic oxidation of ammonia:? N -3 H? О 2 0 =? N +2 O +? H 2 O -2 + Q Combustion of ammonia in oxygen Task: make an electronic balance, indicate an oxidizing agent / reducing agent, oxidation / reducing agent process NH 4 Cl, Ca (OH) 2 KMnO 4 O2O2 NH3

CHECK YOURSELF! 1) 2 N -3 H 3 + = NHN е = N oxidation / reducing agent 3 2H + + 2e = H 2 0 –reducing / oxidizing agent 2) 4 N -3 H О 2 0 = 2 NH 2 O -2 + Q 2 2N е = N oxidation / reducing agent 3 О e = 2О -2 –reduction / oxidizing agent 3) 4 N -3 H О 2 0 = 4 N +2 O + 6 H 2 O -2 + Q 4 N е = N +2 - oxidation / reducing agent 5 О e = 2О -2 - reduction / oxidizing agent

CHEMICAL PROPERTIES OF AMMONIA (associated with the peculiarities of the covalent polar bond in the ammonia molecule) 1) Interaction with water: .. NH3 + HOH NH 4 OH 2) Interaction with acids: .. NH3 + HCl NH 4 Cl Ammonium hydroxide or "ammonia" Chloride ammonium or "ammonia", "smelling salt" Conclusion: ammonia has basic (alkaline) properties

PREPARATION OF AMMONIA 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. The industrial method of producing ammonia is based on the direct interaction of hydrogen and nitrogen: N 2 (g) + 3H 2 (g) 2NH 3 (g) + 45.9 kJ This is the so-called Haber process (a German physicist, developed the physicochemical foundations of the method). NH 4 Cl, Ca (OH) 2 NH3

APPLICATION OF AMMONIA Used for the production of nitrogen fertilizers (ammonium nitrate and sulphate, urea), explosives and polymers, nitric acid, soda (by the ammonia method) and other products of the chemical industry. Liquid ammonia is used as a solvent. In refrigeration technology it is used as a refrigerant.

APPLICATION OF AMMONIA In medicine, a 10% solution of ammonia, often called ammonia, is used for fainting (to stimulate respiration), to stimulate vomiting, as well as externally neuralgia, myositis, insect bites, treatment of the surgeon's hands. To excite breathing and remove the patient from a fainting state, gently bring a small piece of gauze or cotton wool moistened with ammonia to the patient's nose (for 0.5–1 s). The physiological effect of ammonia is due to the pungent smell of ammonia, which irritates specific receptors in the nasal mucosa and stimulates the respiratory and vasomotor centers of the brain, causing increased respiration and increased blood pressure.

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