The presentation "Ammonia" can be used by a chemistry teacher in educational process as an educational electronic thematic manual:
- at chemistry lessons when explaining new and consolidating the material covered on the topic "Non-metals. Ammonia" in grades 9-11;
- in extracurricular work - in extracurricular activities and circles;
- at individual lessons with students;
- in preparing students for practical work for the production, collection and detection of gaseous substances.
So, for example, an explanation of new material in the lesson "Ammonia" can be carried out on the basis of a conversation with students. The teacher can build it around a recurring question - what do you know about:? And then the leading questions of the teacher follow (prepared in advance, depending on the specifics of the class, questions with different differentiation should be selected). The teacher, at his own discretion, can rephrase the questions, change their sequence, reduce their total volume. The teacher supplements the answers of the students with his story and showing the appropriate slides. The explanation of the new material can also be carried out according to another scheme: a slide show (slides), then a teacher's story with elements of a conversation; or - first a teacher's story, then a slide show (slides) and a conversation with students (if appropriate).
The teacher can pause the presentation to show demonstration experiments, or video experiments, working with the electronic board, and then resume working with it.
For greater interest of students in obtaining knowledge on the topic and activating them in the lesson, the teacher invites them to do their homework of a creative nature in advance. The task in the form of questions, chains of transformations is offered to the whole class, or it is distributed among the class groups. Students must prepare answers to questions.
Questions are, for example:
1. How was ammonia obtained, explain the etymology of this word? In which historical time It was?
2. How to properly collect ammonia and prove its presence?
3. What interesting things do you know about ammonia? Where is this substance used?
The teacher can also repeat the material covered on the topic "Chemistry of non-metals" on the basis of the presentation. If there are difficulties with the answers of students, then there is an opportunity to return to the consideration of this issue on the basis of the corresponding slide. The presence of hyperlinks will make it easier to find the desired slide.
Students can also use the presentation "Ammonia" when distance learning, when doing homework, preparing for tests and practical work, self-testing your knowledge on the topic, i.e. with the help of this presentation, it is possible to increase the independent search for knowledge by students, which is especially important when schools switch to the second generation of the Federal State Educational Standard.
The slides present material that will allow you to prepare for the final certification in the format of the GIA and the Unified State Examination. olympiad. In case of difficulty, you can always return to the presentation.
The presence of such an electronic manual as the presentation of "Ammonia" in the chemistry classroom allows the teacher to reduce the time to prepare for the lesson, increase students' interest in studying the topic, increase the level of learning and the quality of students' knowledge of chemistry.
Ammonia NH3
Ammonia - NH3, hydrogen nitride, at normal conditions- a colorless gas with a pungent characteristic odor (the smell of ammonia)
Ammonia is almost twice as light as air, MPCr.z. 20 mg/m3 - IV hazard class (low hazardous substances) according to GOST 12.1.007. The solubility of NH3 in water is extremely high - about 1200 volumes (at 0 °C) or 700 volumes (at 20 °C) in a volume of water. In refrigeration, it is called R717, where R is Refrigerant (refrigerant), 7 is the type of refrigerant (inorganic compound), 17 is the molecular weight.
The ammonia molecule has the shape of a trigonal pyramid with a nitrogen atom at the top. Three unpaired p-electrons of the nitrogen atom participate in the formation of polar covalent bonds with 1s-electrons of three hydrogen atoms (N-H bonds), the fourth pair of external electrons is lone, it can form a donor-acceptor bond with a hydrogen ion, forming an ammonium ion NH4+. Due to the fact that the non-bonding two-electron cloud is strictly oriented in space, the ammonia molecule has a high polarity, which leads to its good solubility in water.
Condition (St. cond.)tgas
Molar mass t17.0306 g/mol
Density t0.0007723 (n.s.)
Physical properties
Condition (St. cond.)tgas
Rel. molek. mass t17.0306 a. eat.
Molar mass t17.0306 g/mol
Density t0.0007723 (n.s.)
Physical properties
Condition (St. cond.)tgas
Rel. molek. mass t17.0306 a. eat.
Molar mass t17.0306 g/mol
Density t0.0007723 (n.s.)
Physical properties
Application
Ammonia is one of the most important products of the chemical industry, its annual world production reaches 150 million tons. Mainly used for the production of nitrogen fertilizers (ammonium nitrate and sulfate, urea), explosives and polymers, nitric acid, soda (according to the ammonia method) and other products of the chemical industry. Liquid ammonia is used as a solvent.
In refrigeration, it is used as a refrigerant (R717)
In medicine, a 10% solution of ammonia, often called ammonia, is used for fainting (to stimulate breathing), to stimulate vomiting, as well as externally - neuralgia, myositis, insect bites, and to treat the surgeon's hands. If used incorrectly, it can cause burns of the esophagus and stomach (in case of taking an undiluted solution), reflex respiratory arrest (when inhaled in high concentrations).
Apply topically, inhalation and inside. To excite breathing and bring the patient out of fainting, carefully bring a small piece of gauze or cotton wool moistened with ammonia to the patient's nose (for 0.5-1 s). Inside (only in breeding) to induce vomiting; also, as part of ammonia-anise drops - as a mucolytic (expectorant) agent. With insect bites - in the form of lotions; with neuralgia and myositis - rubbing with ammonia liniment. In surgical practice, they are bred in warm boiled water and wash their hands.
Since ammonia is a weak base, it neutralizes acids when interacting with them.
The physiological effect of ammonia is due to the pungent smell of ammonia, which irritates specific receptors of the nasal mucosa and excites the respiratory and vasomotor centers of the brain, causing increased breathing and increased blood pressure.
Antifreeze additive for dry mortars related to accelerators. The recommended dosage is 2…8% by weight of the components of the dry mixture, depending on the application temperature. Ammonia water is a product (NH3*H2O), which is gaseous ammonia NH3 dissolved in water.
Application
For insect bites, ammonia is applied externally in the form of lotions. 10 % water solution ammonia is known as ammonia.
Side effects are possible: with prolonged exposure (inhalation use), ammonia can cause reflex respiratory arrest.
Topical application is contraindicated for dermatitis, eczema, other skin diseases, as well as for open traumatic injuries of the skin.
In case of accidental damage to the mucous membrane of the eye, rinse with water (for 15 minutes every 10 minutes) or a 5% solution of boric acid. Oils and ointments are not used. With the defeat of the nose and pharynx - 0.5% solution of citric acid or natural juices. In case of ingestion, drink water, fruit juice, milk, preferably 0.5% citric acid solution or 1% acetic acid solution until the contents of the stomach are completely neutralized.
Interaction with other drugs is unknown.
Ammonia in medicine
Ammonia
Tasks to repeat
- Carry out a chain of transformations:
- N 2 →Li 3 N→NH 3 →NO→NO 2 →HNO 3
- Determine the coefficients in the reaction equation using the electron balance method:
- Determine the coefficients in the reaction equation using the electron balance method:
- NH 3 + O 2 → NO + H 2 O
- NH 3 + O 2 → N 2 + H 2 O
This story took place during World War I.
The structure of ammonia
(NH 3 )
+7 N ))
+1 h)
Physical properties
- Ammonia - This colorless gas with sharp smell, 2 times lighter than air .
- Ammonia must not be inhaled long time, because He poisonous.
- It liquefies easily.
- On contact with the skin, frostbite of varying degrees occurs.
- T pl = -78 0 WITH
- Highly soluble in water:
a) 25% solution - aqueous ammonia (ammonia water)
B) 10% solution - ammonia.
T kip = -33,5 0 WITH
- According to the donor-acceptor mechanism:
A) Interaction with acids:
NH 3 + HCl \u003d NH 4 Cl
:NH 3 +□H + = NH 4 +
B) Interaction with water:
NH 3 + H 2 O ↔ NH 4 OH
ACCEPTOR
DONOR
Chemical properties
2) Interaction with metals:
2NH 3 + Na \u003d NaNH 2 + H 2
2NH 3 + O 2 \u003d 2H 2 O + N 2
2NH 3 + 3Br 2 \u003d 6HBr + N 2
Ammonia production
1) Industrial: synthesis from nitrogen and hydrogen:
N 2 + 3H 2 ↔2NH 3
2) Laboratory:
Ca (OH) 2 + NH 4 Cl \u003d CaCl 2 + NH 3 + 2H 2 O
Receipt
In the laboratory
NH 3
NH 4 Cl
Ca(OH) 2
Application
Production of nitrogen
In refrigeration
installations.
In medicine,
for soldering
Production
fertilizer
Production
explosive
Check of knowledge
1. What is the oxidation state of nitrogen in ammonium nitrate?
2. Compose chemical equations the following transformations:
nitrogen→ammonia→ammonium chloride
3. Additional task: Determine the coefficients in the following diagram chemical reaction using the electronic balance method:
Cu + NH 3 → N 2 + Cu + H 2 O
Homework
slide presentation
Slide text: Lesson topic: Ammonia “You can not love chemistry, but you cannot live without it today and tomorrow” O.M. Nefyodov
Slide text: Meet ammonia HNO3 production Medicine A product of protein metabolism in living organisms Fertilizer production Detergents Hair dye Coolant in refrigerators Today, ammonia is an extremely important raw material for the production of nitrogen-containing substances used in agriculture, chemistry, medicine, military affairs And no less important, it is one of the products of protein metabolism in the body.
Slide text: History of the discovery of ammonia In the middle of the Libyan desert stood a temple dedicated to the god Amon Ra. In ancient times, Arab alchemists obtained colorless crystals from the Amon oasis, located near the temple. ground in mortars, heated - and received a caustic gas. At first it was called ammonia, and then the name was shortened to "ammonia". In the 18th century, ammonia was discovered by the English chemist Joseph Priestley. Today, ammonia is an extremely important raw material for the production of nitrogen-containing substances used in agriculture, chemistry, medicine, and military affairs. And no less important, it is one of the products of protein metabolism in the body.
Slide text: Production of ammonia (NH3) t NH4Cl+ Ca(OH)2 CaCl2+2NH3+2H2O Fe,t,p N2+ 3H2 2NH3+ Q
Slide text: 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 - TOXIC! Liquid ammonia causes severe skin burns; usually it is transported in steel cylinders (painted in yellow, have the inscription "Ammonia" in black) Ammonia - 3-10% ammonia solution Ammonia water - 18-25% ammonia solution Ammonia-air mixture is explosive!
Slide text: The structure of the ammonia molecule ▪ ▪ ▪ H * * * H H │ N ▪▪ The nitrogen atom due to its unpaired electrons forms 3 covalent polar bonds with hydrogen atoms => the valency of N is III. The unshared electron pair of the nitrogen atom is able to participate in the formation of the fourth covalent bond with atoms having a vacant (free) orbital according to the donor-acceptor mechanism. The valency of N is IV Mechanism of donor-acceptor bond: H3N: + H+ = + ammonium ion
Slide text: Chemical properties of ammonia Reactions that occur with a change in the oxidation state of nitrogen NH3 is a strong reducing agent without changing the oxidation state of nitrogen NH3 is a weak base 1. ammonia is an unstable compound, decomposes when heated: 2NH3 N2 + 3H2 2. ammonia burns in oxygen: NH3 + O2 → N2 + H2O 3. oxidation of ammonia with air 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
Slide text: Good old ammonia, He is rich and he is poor, Rich in his unshared electrons, But only, that's the trouble, he's bored alone in solution. He is always ready to take a walk: There is acid, and here is water... Then, robbed to the skin, He cries: “Where are my belongings? What an iniquity: I have become an ammonium cation!”
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Slides captions:
Ammonia NH 3 Kirillova Margarita Alekseevna teacher of chemistry at Lyceum No. 369 of the Krasnoselsky district
The structure of the nitrogen atom N Nitrogen 14.0067 2 5 7 2 s 2 2p 3 N 7 N II period V group 2 s 2p , each with one unpaired electron.
Formation of the ammonia molecule When bonds are formed in the ammonia molecule, the nitrogen atom is in the state of sp 3 - hybridization. 109 0 28 ’: N + H: N: H H H H: : H H H H The shape of the molecule is pyramidal. H: : H
The structure of ammonia molecules Hydrogen bonds form between ammonia molecules: N-H bonds polar, the molecule has a pyramidal shape, common electron pairs are shifted towards the nitrogen atom. One of the vertices is occupied by a lone pair of electrons. The molecule is highly polar.
Physical properties of ammonia A colorless gas with a pungent odor. Almost two times lighter than air: When cooled to -33 0 C - c liquefies. It dissolves very well in water, tk. hydrogen bonds are formed between ammonia molecules and water molecules (700 V of ammonia dissolves in 1 V of water. 10% solution - “ammonia alcohol”. A concentrated solution contains 25% ammonia.
Methods for producing ammonia In industry: N 2 + 3H 2 2NH 3 The reaction is carried out by heating, under pressure, in the presence of a catalyst. In the laboratory: The action of alkalis on ammonium salts: 2NH 4 Cl + Ca (OH) 2 \u003d CaCl 2 + 2NH 3 + 2H 2 O Hydrolysis of nitrides: Mg 3 N 2 + 6H 2 O \u003d 3Mg (OH) 2 + 2NH 3
Chemical properties of ammonia NH 3 - the lowest oxidation state of nitrogen. -3 1. Ammonia - reducing agent Ammonia combustion reaction: 4NH 3 + 3O 2 = 2N 2 + 6H 2 O Catalytic oxidation of ammonia: 4NH 3 + 5O 2 = 4NO + 6H 2 O Ammonia can reduce some inactive metals: 3CuO + 2 NH 3 \u003d 3Cu + N 2 + 3H 2 O
II. The main properties of ammonia: When ammonia is dissolved in water, ammonia hydrate is formed, which dissociates: NH 3 + H 2 O NH 3 H 2 O NH 4 + + OH - ammonium ion Changes the color of indicators: Phenolphthalein - b / color raspberry Methylorange - orange yellow Litmus - violet blue Forms ammonium salts with acids: NH 3 + HCl \u003d NH 4 Cl ammonium chloride 2NH 3 + \u003d (NH 4) 2 SO 4 ammonium sulfate NH 3 + H 2 SO 4 \u003d NH 4 HSO 4 ammonium hydrosulfate
The formation of the ammonium ion NH 3 + H + \u003d NH 4 + H:: H H:: H N N: H: + H + H:: H H:: N N: H: + The nitrogen atom is in the state of sp 3 - hybridization. Three bonds are formed by the exchange mechanism, the fourth - by the donor-acceptor mechanism. The donor, the nitrogen atom, provides a pair of electrons. The acceptor - ion H + - provides an orbital.
Ammonium salts The ammonium ion is similar in size and charge to ions alkali metals, so ammonium salts are similar to alkali metal salts. crystalline substances. White. Well soluble in water. Their dissolution in water is accompanied by the absorption of heat. Qualitative reaction to the ammonium ion - the interaction of salts with alkali solutions: NH 4 NO 3 + NaOH \u003d NaNO 3 + NH 3 + H 2 O characteristic pungent smell of ammonia
Decomposition of ammonium salts when heated Salts of volatile acids: NH 4 Cl \u003d NH 3 + HCl (NH 4) 2 CO 3 \u003d 2NH 3 + CO 2 + H 2 O C oli of non-volatile acids: (NH 4) 2 SO 4 \u003d NH 4 HSO 4 + NH 3 (NH 4) 3 PO 4 \u003d (NH 4) 2 HPO 4 + NH 3 without heating (NH 4) 2 HPO 4 \u003d NH 4 H 2 PO 4 + NH 3 with heating Salts with an oxidizing anion : (NH 4) 2 Cr 2 O 7 \u003d N 2 + Cr 2 O 3 + 4H 2 O NH 4 NO 3 \u003d N 2 O + 2H 2 O NH 4 NO 2 \u003d N 2 + 2H 2 O
Nitric acid Ammonium nitrate Ca(NO 3) 2 Ammonium sulfate (NH 4) 2 SO 4 Ammonium chloride NH 4 Cl Carbamide (urea) CO(NH 2) 2 Ammonia water NH 3 H 2 O Liquid ammonia NH 3 Ammonia Nitrogen fertilizers Drug production Rocket fuel oxidizer Ammonium salts for soldering Explosives Production of soda Refrigerant in industrial refrigeration plants Production of photographic film and dyes Processing of precious metals Use of ammonia and ammonium salts
Thank you for attention
