Date: Teacher: Omelyanenko Yu.A.
Lesson from topic number 4 "Non-metals and their compounds."
Chemistry lesson in 9th grade.
Lesson topic: Carbon monoxide (IV): the structure of the molecule, obtaining, physical and chemical properties, application.
The purpose of the lesson: to create conditions for the best assimilation of knowledge about carbon dioxide, its structure, properties, production and biological role in the life of living organisms.
Tasks:
educational
to promote the expansion of students' knowledge about substances through the study of non-metal oxides, their role in human life and nature;
to form the ability to classify binary compounds, to compose their formulas;
introduce students to the production and use of carbon monoxide (IV);
Consider the physical and chemical properties of carbon dioxide.
Educational
to promote the formation of students' ability to set goals, define tasks, analyze and draw conclusions;
develop attention, logical thinking;
develop the ability to work in a group.
Educational
to promote the development of students' initiative, interest in the subject, culture of communication;
creating a favorable psychological environment;
cultivate respect for the environment.
Skills and abilities of students:
subject:
Know the structure of the carbon dioxide molecule and can determine the type of chemical bond;
Know how to obtain this oxide;
Describe the physical and chemical properties of carbon monoxide (IV);
They understand the importance of this substance in the life of living organisms and the planet as a whole.
metasubject:
- can summarize the information received, classify objects according to the proposed criteria;
They are able to formulate a definition, select arguments;
Perform the learning task in accordance with the goal;
Carry out the training action in accordance with the plan.
personal:
Assess their academic achievements;
Develop intellectual and creative abilities.
Lesson type: Combined lesson.
Equipment: multimedia projector, envelopes with additional information and questions for reflection, colored cards, cards for checking homework, chemical reagents and equipment.
During the classes
Organizing time.
Greetings, checking readiness for the lesson.
Motivation of educational activity.
Guys, I want to start today's lesson with the words of a great scientist, physicist, very interesting person Nilson Bohr, who said that opposites are not contradictions, they are additions.slide 1. I really hope that in today's lesson we will be a great complement to each other. Let's work productively and discover new knowledge.
Checking homework.
In the last lesson, we talked with you about carbon and carbon monoxide (II) (carbon monoxide). I suggest checking how you learned the material and worked at home. Choose a yes or no answer to the given statement. You can also use the "don't know" option. On the cards for testing, write down your last name and fill it out.
Graphite is a transparent crystalline substance, which is the hardest substance of all natural substances (none).
Diamond and graphite are allotropic modifications of carbon (yes).
Electrodes are made from diamond, as it conducts electricity (no).
Carbon monoxide is not poisonous (no).
Carbon can have oxidation states in compounds +2, +4 (yes).
Carbon monoxide (II) is a product of incomplete combustion of carbon (yes).
The difference between graphite and diamond is explained by the difference in the structure of the crystal lattice (yes).
CO is a non-salt-forming oxide (yes).
During photosynthesis, carbon monoxide is absorbed (no).
Carbon with a valence of 2 at the last energy level contains two unpaired electrons (yes).Slide 2.
Peer review and evaluation is carried out.Slide 3.
Announcement of the topic of the lesson.
Guys, can we say that the topic of carbon is over, and we have covered all the most important carbon compounds? Of course not. We still do not know much about carbon compounds, so today we will continue to talk about a substance containing carbon, which plays a huge role in the life of all living beings and the planet as a whole. And what kind of substance is now determined with the help of a chemical experiment and knowledge about the properties of salts.
Demo Experience . The interaction of sodium carbonate and hydrochloric acid. In this case, we observe a violent reaction with the release of gas bubbles. Safety regulations. Laboratory method for obtaining carbon dioxide.
We write the reaction equation on the blackboard and draw conclusions about what substance we are talking about.
We all know the formula for carbon dioxide. What is the nomenclature for this substance? Right.
Lesson topic: Carbon monoxide ( IV) .
Learning new material.
Carbon dioxide is a substance that we do not notice, but do we all know about it. I suggest you watch the video clip, and you think about whether you can immediately explain what is happening.slide 4 . And, here's another story: in Naples there is a cave called "dog cave". When a dog enters, it dies, but the man does not. What do we need to know about carbon dioxide to answer the questions.
Students formulate:
Physical and chemical properties;
biological significance.
Sometimes it's good to look at things from different angles. I suggest you conduct our lesson in the form of 5 lessons: drawing, natural science, physical education, mathematics and literature (extracurricular reading).
But for this it is necessary to form groups.
Method of "random groups".
So, the first lesson is drawing. Before you is a painting by an unknown artist, presumably the second half of the 20th century. The artist was an avant-garde artist, he painted something. Try to explain what the artist wanted to convey.
The slide shows the structural electronic formula carbon dioxide.slide 5 . Type of chemical bond, electronegativity.
Now let's move on to natural science. Guys, what is this? That's right - this is a complex of sciences about nature.
1 group today will be in the role of biologists, and to study the biological significance of carbon dioxide, they present their work in the formposter.
2 group are physics. You need to analyze the physical properties of carbon dioxide and create a smallpresentation.
3rd group - consider, remember the chemical properties of oxides, namely carbon monoxide (4) and make up on the boardcluster.
You can get information from the textbook and the envelope that your leaders received. Guys, pay attention, you will be limited in time. You have 10 minutes to work. For implementation feedback, there are signal cards on the tables. If you need my advice, please raise it. Begin.
Presentation of works. Thank you guys! Guys, now can we explain what kind of "carbon dioxide snow" appeared in the video clip? Why do dogs die in the cave?
Now let's move on to physical education. I suggest you do breathing exercises.
Physical education (breathing exercises).
We do 4 breaths and exhalations.
We take a deep breath and two exhalations (4 times).
Guys, when we breathe, what do we emit? How to prove?
Demonstration experiment (qualitative reaction to carbon dioxide): the glass contains lime water, where the tube is lowered. The student exhales carbon dioxide into the tube. The lime water should turn cloudy.
What reaction did we just have?
Consolidation of educational material.
I promised that there would be a math lesson.
Problem solving (preparation for the GIA).
Baking soda (sodium bicarbonate), used in cooking and Food Industry, when heated, it decomposes, and due to the release of gas, the dough loosens. What volume of carbon dioxide (N.O.) will be released during the decomposition of 8.4 g of sodium bicarbonate?
Homework.
Guys, at home, read paragraph 34, make a small reference summary on the topic, and also try to answer the questions:
Why can't people breathe carbon dioxide?
What is a "sinking flame" and what is the essence of this phenomenon?
This will be your extracurricular reading.
Reflection.
You have questions in the envelopes for each group, try to answer them now:
What feelings did you have while working? (curiosity, interest, job satisfaction).
What have you learned? What did you learn new?
What difficulties did you encounter?
What made us achieve the result? (Due to solidarity, etc.)
How can you connect the acquired knowledge with life?
Guys, thanks for the tutorial!
Grade_______________
Assessment card ____________________
(For each correct answer - 0.5 points; incorrect - 0 points)
Grade_______________
slide 1
Project on the topic: "Carbon dioxide"
Performed by students of 11 "A" class MBOU "School" No. 31 Rytikova Alesya, Harakhashyan Mateos, Khilko Ekaterina, Shonia David, Bitsulya Grigory
slide 2
I. The structure of carbon dioxide molecules
Carbon dioxide molecules always consist of two oxygen atoms and one carbon atom. It is impossible to obtain a carbon dioxide molecule from a different number of carbon and oxygen atoms. Within the framework of the theory of hybridization of atomic orbitals, two σ-bonds are formed by sp-hybrid orbitals of the carbon atom and 2p-orbitals of the oxygen atom. The p-orbitals of carbon that do not participate in hybridization form p-bonds with similar oxygen orbitals. The molecule is non-polar.
slide 3
II. Discovery of carbon dioxide.
Carbon dioxide was the first among all other gases to be opposed to air under the name "wild gas" by the 16th century alchemist Van't Helmont. The discovery of CO2 marked the beginning of a new branch of chemistry - pneumatochemistry (gas chemistry). The Scottish chemist Joseph Black (1728–1799) found in 1754 that the calcareous mineral marble (calcium carbonate) decomposed on heating with the release of gas and formed quicklime (calcium oxide): CaCO3CaO + CO2 The liberated gas could be recombined with calcium oxide and get calcium carbonate again: CaO + CO2CaCO3 This gas was identical to the "wild gas" discovered by Van Helmont, but Black gave it a new name - "bound air" - since this gas could be bound and a solid substance - calcium carbonate - could be obtained again. A few years later, Cavendish discovered two more characteristic physical properties carbon dioxide - its high density and significant solubility in water.
slide 4
III. Physical Properties
Carbon monoxide (IV) - carbon dioxide, a colorless and odorless gas, heavier than air, soluble in water, with strong cooling, it crystallizes in the form of a white snow-like mass - “dry ice”. At atmospheric pressure, it does not melt, but evaporates, the sublimation temperature is -78 ° C. Carbon dioxide is formed during the decay and combustion of organic matter. Contained in the air and mineral springs, released during the respiration of animals and plants. Slightly soluble in water (1 volume of carbon dioxide in one volume of water at 15 ° C).
slide 5
IV. Getting carbon dioxide
Obtaining carbon dioxide in industry: Carbon monoxide 2 burns in oxygen and in air with the release of a large amount of heat: 2CO + O2 \u003d 2CO2 In the same way, carbon dioxide can be obtained in the laboratory. Carbon monoxide 2 is a strong reducing agent, therefore it is used in industry to reduce iron ores: Fe2O3 + 3CO = 2Fe + 3CO2 In industry, carbon monoxide 4 is obtained by burning coal or calcining limestone: CaCO3 = CaO + CO2 Obtaining carbon dioxide in the laboratory: B laboratories, CO2 is obtained by the action of acids on carbonic acid salts H2CO3: Na2CO3 + H2SO4 \u003d Na2SO4 + CO2 + H2O When acids act on carbonates and their solutions, carbon dioxide is released, causing the solution to foam: CaCO3 + HCl \u003d CaCl2 + CO2 + H2O
slide 6
V. Recognition of carbon dioxide
To detect carbon dioxide, the following reaction can be carried out: CaCO3 + 2HCl \u003d CaCl2 + CO2 + H2O A solid or solution containing CO3 acts as an acid, emitting CO2 is passed through lime water (saturated solution of Ca (OH) 2) and as a result of precipitation of a sparingly soluble carbonate the calcium solution becomes cloudy.
Slide 7
VI. Application of carbon dioxide
Carbon dioxide is used in many industries. For example: 1.Chemical industry; 2.Pharmaceuticals; 3. Food industry; 4.Medicine; 5. Metallurgical industry; 6.Laboratory research and analysis; 7.Pulp and paper industry; 8.Electronics; 9. Environmental protection.
Slide 8
VII. Found in nature The content of carbon dioxide in the atmosphere is relatively small, about 0.03% (by volume). Carbon dioxide concentrated in the atmosphere has a mass of 2200 billion tons. 60 times more carbon dioxide is found in dissolved form in the seas and oceans. During each year, about 1/50 of the total CO2 contained in it is extracted from the atmosphere by the vegetative cover of the globe in the process of photosynthesis, which converts minerals into organic substances. The bulk of carbon dioxide in nature is formed as a result of various processes of decomposition of organic substances. Carbon dioxide is released during the respiration of plants, animals, microorganisms. The amount of carbon dioxide emitted is constantly increasing various industries. Carbon dioxide is contained in the composition of volcanic gases, it is also released from the earth in volcanic areas. Outside the globe, carbon monoxide (IV) has been found in the atmospheres of Mars and Venus, "terrestrial-type" planets.
Slide 9
Thank you for your attention!
slide 2
Carbon dioxide
Carbon dioxide is colorless and odorless. It is almost 1.5 times heavier than air. Under normal conditions, one volume of carbon dioxide dissolves in one volume of water.
slide 3
Air always contains about 0.3% carbon dioxide. Its content in the air is unstable. Air in cities, especially near plants and factories, contains slightly more carbon dioxide than air in rural areas.
slide 4
Carbon dioxide is formed during respiration and combustion of fuel, as well as during smoldering and decay of various organic substances.
The water of many mineral springs contains significant amount dissolved carbon dioxide. One of these sources of mineral water is located in Kislovodsk. Every day this spring brings out about two and a half million liters of mineral water containing up to 5 g of free carbon dioxide.
slide 5
The waters of the seas and oceans contain a lot of dissolved carbon dioxide, ten times more than in the air.
slide 6
When the pressure is increased to 60 atm, it turns into a colorless liquid. When liquid carbon dioxide evaporates, part of it can turn into a solid snow-like mass. It is pressed and the so-called "dry ice" is obtained, which sublimates under normal pressure without melting, and its temperature drops to -78.5 ° C. Therefore, dry ice is mainly used for storage food products and especially ice cream.
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Slides captions:
Carbon oxides Teacher chemistry MOU"KSOSH No. 7" Gareeva O.I.
Obtaining carbon monoxide (II) industrial way 1. It is formed during the combustion of carbon or compounds based on it (for example, gasoline) under conditions of lack of oxygen: 2C + O 2 \u003d 2CO 2. When carbon monoxide (IV) is reduced with hot coal: CO 2 + C \u003d 2CO This reaction often occurs when furnace furnace.
Obtaining carbon monoxide (IV) 1. In industry, they are obtained by roasting natural carbonates (limestone, dolomite). CaCO 3 \u003d CaO + CO 2 2. In laboratory conditions, it is obtained by the interaction of carbonates and bicarbonates with acids, for example marble, chalk or soda with hydrochloric acid: CaCO 3 + 2HCI \u003d CaCI 2 + H 2 O + CO 2 Can be used to make drinks reaction of baking soda with citric acid or sour lemon juice.
Physical properties CO - carbon monoxide (II), carbon monoxide, carbon monoxide Gas, colorless, odorless, lighter than air, slightly soluble in water, much better soluble in alcohol, T. pl. -205.02 0 C, bp -191.5 density 1.25 g/l (0 0 C) Very poisonous! CO 2 - carbon monoxide (IV), carbon dioxide, carbon dioxide. Gas, colorless, odorless, 1.5 times heavier than air, soluble in water, density 1.98 g/l So pl. −57 °C), T, kip −78 °C, sublimates. The solid oxide is called "dry ice"
Chemical properties carbon monoxide (II) At room temperature, CO is inactive, its chemical activity increases significantly when heated and in solutions CO is a non-salt-forming oxide 1. When heated, it reduces metals from oxides: CO + CuO → Cu + CO 2 2. Burns in air with a blue flame ( reaction start temperature 700 °C): 2 CO + O 2 → 2CO 2 + Q The combustion temperature of CO can reach 2100 °C.
Chemical properties of carbon monoxide (IV) CO 2 - acid oxide 1. Interacts with water, forming an unstable carbonic acid(reversible reaction) CO 2 + H 2 O H 2 CO 3 2. Interacts with alkalis, forming carbonates and bicarbonates CO 2 + Ca (OH) 2 = CaCO 3 ↓ + H 2 O CaCO 3 + CO 2 + H 2 O = Ca (HCO 3) 2 3. Interacts with basic oxides CO 2 + CaO = CaCO 3
The use of carbon monoxide (II) As a reducing agent, CO is used in metallurgy for iron smelting.
Water gas is used as a fuel, and is also used in chemical synthesis - to obtain ammonia, higher alcohols, etc.
Carbon monoxide(II) is used to treat animal meat and fish, giving them a bright red color and a fresh appearance, without changing the taste. The permissible concentration of CO is 200 mg/kg of meat.
The use of carbon monoxide (IV) Carbon dioxide is used to carbonate fruit and mineral waters, for the production of sugar, in medicine for carbonic baths.
In the food industry, carbon monoxide (IV) is used as a preservative and is indicated on the packaging under the code E290, as well as a dough baking powder.
Cylinders with liquid carbon dioxide are widely used as fire extinguishers 1) in portable fire extinguishers; 2) in fire extinguishing systems of aircrafts and ships, carbon dioxide fire engines. Such widespread use in fire extinguishing is due to the fact that in some cases water is not suitable for extinguishing.
Technologies for cleaning various surfaces with "dry ice" granules. Cleaning injection molds with "dry ice"
Solid carbon dioxide - dry ice - is used in glaciers. Liquid carbon dioxide is used as a refrigerant and working fluid in refrigerators, freezers, and solar power generators.
Scientists have found a way to use carbon dioxide: it can be used to make polycarbonate, which is used to make CDs. The first DVDs and plastic bottles from CO 2 may appear on sale in a couple of years.
The biological significance of carbon dioxide Carbon monoxide (IV) plays one of the main roles in wildlife, participating in many metabolic processes of a living cell. Atmospheric carbon dioxide is the main source of carbon for plants. Plants take in carbon dioxide during photosynthesis,
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