Lesson outline "introduction to organic chemistry". Teacher Universities Open Lesson Introduction to Organic Chemistry
1. greeting
2. checking students’ readiness for the lesson
3. message about the topic of the lesson and its main objectives
Since ancient times, humanity has used substances of plant and animal origin to satisfy its needs: food, clothing, substances for tanning leather, vegetable "and essential oils. As civilization developed, people learned to isolate and use natural dyes, medicinal and aromatic substances, natural fibers, poisons, intoxicants and intoxicants.
Ancient manuscripts, chronicles and handwritten books brought to us the knowledge of our distant ancestors about the methods of isolating and using substances of the “plant and animal world”. Alchemists, for example, knew how to obtain concentrated acetic acid and its salts: copper (II) acetate (verdigris) and lead (II) acetate (lead sugar).
The first attempts to classify substances into organic and inorganic were made in the 9th-10th centuries. The Arab alchemist Abu Bakr ar Razi (865-925) was the first to divide substances into representatives of the “mineral, plant and animal kingdoms.” This classification lasted almost 1000 years!
What was this division of substances based on? It has long been noted that “plant and animal” substances have similar properties: they are easily destroyed when heated, burn, many of them dissolve in alcohols and oils. The systematic study of these “delicate” substances began with the work of outstanding scientists: the Swedish chemist K. Scheele and the creator of scientific chemistry, the Frenchman A. Lavoisier. They allocated in pure form from plant and animal bodies, many organic acids (oxalic, malic, citric, lactic), glycerin, esters acetic and benzoic acids.
At the end of the XVIII - early XIX V. science was dominated by a doctrine called vitalism (from Latin vita - life). Proponents of vitalism argued that any substances of living nature can be formed in living organisms only under the influence of a special “ vitality" The vitalists argued that the most important fundamental synthesis on our planet is photosynthesis impossible outside of green plants. 6С0 2 + 6H 2 0 C 6 H 12 0 6 + 60 2.
At the beginning of the 19th century. There is a need to separate the chemistry of substances of plant and animal origin into an independent science. The emergence of this science is associated with the name of the famous Swedish chemist.. Jens Jacob Berzelius, who gave it the name “organic chemistry”. Organic chemistry is the chemistry of carbon compounds (except for the simplest: carbon oxides, carbonic acid and its salts).
Natural, artificial and synthetic organic compounds are almost always composed of carbon and hydrogen atoms. Organic compounds often also contain atoms of oxygen, nitrogen and some other elements. Organic compounds built by these elements (primarily carbon and hydrogen). b about 30 million are taken into account, whereas inorganic substances, formed by all 110 elements of D.I. Mendeleev’s table, there are only 100 thousand.
However, the further development of chemistry and the accumulation of new scientific facts proved that the vitalists were deeply mistaken. In 1828, the German chemist F. Wöhler synthesized the organic compound urea from the inorganic substance ammonium cyanate. The Zuz scientist M. Berthelot obtained fat in a test tube in 1854. In 1861 Russian chemist A.M. Butlerov synthesized a sugary substance. Subsequently, the chemist Wöhler wrote in a letter to Berzelius in 1835. He wrote: “organic chemistry can drive anyone crazy now. It seems to me like a dense forest, full of amazing substances, a boundless thicket from which you cannot get out, into which you do not dare to penetrate.” Vitalism has failed
All variety organic compounds by origin can be divided into three types:natural, artificial and synthetic.
Natural organic compounds- these are waste products of living organisms (bacteria, fungi, plants, animals). These are proteins that are well known to you, fats, carbohydrates, vitamins, hormones, enzymes, natural rubber, etc. (Fig. 2 in the textbook).
Artificial organic compounds- these are products of chemically transformed natural substances into compounds that are not found in living nature. Thus, based on the natural organic compound cellulose, artificial fibers (acetate, viscose, copper-ammonia), non-flammable film and photographic films, plastics (celluloid), smokeless powder, etc. are produced (Figure 3 in the textbook).
Synthetic organic compoundsobtained synthetically, that is, by combining simpler molecules into more complex ones. These include, for example, synthetic rubbers, plastics, medicines, synthetic vitamins, growth stimulants, plant protection products, etc. (Fig. 4 in the textbook).
For inorganic chemistry the leading theoretical basis is the Periodic Law and Periodic table chemical elements D.I. Mendeleev, and for organic chemistry such a basis is the theory of the chemical structure of organic compounds by A.M. Butlerov.
What is it chemical structure? Let me remind you that chemical structure refers to the order in which atoms are combined into molecules according to valence. What is it valence. Consequently, valence is determined by the number of covalent bonds, i.e. the number of common electron pairs, regardless of the mechanism by which these pairs were formed - exchange or donor-acceptor.
Note that in organic chemistry the concept of “valency” is an analogue of the concept of “oxidation state”, which you widely used in inorganic chemistry. But these concepts are not equivalent, since valence has no sign and cannot be zero, while the oxidation state is necessarily characterized by a sign and can have a value equal to zero.
In order to show the difference between valence and oxidation state, the teacher asks students to consider the substances formed by the chemical element nitrogen:
In organic chemistry, the order of connection of atoms in molecules of substances by valency, i.e., their chemical structure, is reflected using structural formulas - full and abbreviated.
And so determine the oxidation state of carbon methane CH 4, ethane C 2 H 6 and propane C 3 H 8 taking into account the fact that carbon in organic compounds is always tetravalent.
And so let’s write down what organizational chemistry is
Organic chemistrythere is the chemistry of hydrocarbons and their derivatives (i.e., products formed when hydrogen in the molecules of these substances is replaced by other atoms or groups of atoms)
Lesson topic: “Introduction to organic chemistry»
Item
: Chemistry Class: 9
Purpose of the lesson
: Creating conditions for “immersion” in organic chemistry.
Lesson objectives:
Educational
. Explore chemical composition organic substances, identify the difference between organic substances and inorganic ones, determine the subject of study of organic chemistry, the goals and objectives of organic chemistry.
Developmental.
Develop the ability to work with primary sources and additional information: highlight the main thing and draw up a supporting summary. Develop skills in conducting chemical experiments, observing safety rules. Develop the ability to observe, compare, and draw conclusions. Develop memory, logical thinking, attention.
Educational
. To cultivate neatness, hard work, patriotic, aesthetic and moral qualities.
Lesson type:
A lesson in learning new material.
Lesson technical support:
Multimedia projector, computer, equipment and reagents for conducting a chemical experiment.
Expected result:
- define concepts: subject of organic chemistry, organic substances
- compare organic and inorganic substances
- know the goals and objectives of organic chemistry,
- name the names of organic scientists
- be able to identify organic substances in plant objects.
Lesson progress
Org moment.
Good morning guys. Good morning, dear guests! Let's smile at each other! And with good mood Let's start our lesson. I hope the lesson will be productive for you, and most importantly, useful!
I want to start the lesson with the words of M. Gorky: “First of all and most carefully, study chemistry. This is an amazing science, you know... Her keen, bold gaze penetrates into the fiery mass of the sun and into the darkness earth's crust, into the invisible particles of your heart, and into the secrets of the structure of a stone, and into the silent life of a tree. She looks everywhere and, discovering harmony everywhere, persistently seeks the beginning of life..."
I .Challenge and goal setting stage
Today you will work in groups and pairs. And pay attention, we have 11th graders sitting in the third row. Why are they here? Yes, to help you study chemistry. Well, we will find out what section they are studying as the lesson progresses.
Open your notebooks and write down the number.
Guys, let’s make a cluster - write the words “ chemicals». We work in pairs. Each pair makes up its own cluster.
Cluster prepared on the board slide1
What associations do you have with these words? Label examples of chemicals that you are familiar with from everyday life around the words "chemicals".
Slide 2
For two years, you and I studied one section of chemistry called “inorganic chemistry.” Look at the diagram and list the substances that are classified as inorganic substances.
Called inorganic substances (water, oxygen, etc....)
What substances have we not yet studied, name them?Sugar, starch, fats, proteins...
Here are two collections in front of you, look carefully, how are they similar and how are they different? What groups can you divide these collections into?
What branch of chemistry do you think studies these substances?organic chemistry.
Let's remember what we studied in the inorganic chemistry section.-9th grade.
What classes of substances exist in inorganic chemistry?Oxides, acids, salts, bases
What classes does the organic chemistry section study? -11th grade
From today's lesson we begin to study the section - organic substances and the topic of our lesson (formulate):"Subject of organic chemistry."
Let's return to the cluster.
These organic substances are familiar to you. What is included in themcompound ? Do we know? - 9Class
What do they havestructure ? Do we know? -9th grade
Distinctive features How do they differ from inorganic substances?
Which substances are more numerous - organic or inorganic?(reasons for diversity ) - 9 Class
Look at page 214. Which substances are there more?
II . Content comprehension stage
Look how many questions we have! We will look for answers to the questions posed in class!
I suggest using the help of 11th grade.
Working with 11 Klaas
Group 1. How were organic substances obtained in ancient times? Why are these substances called organic?
Answer: All organic substances were obtained exclusively from waste products of plant and animal organisms or as a result of their processing. This is where the name “organic matter” comes from.
Group 2. What does organic chemistry study?
Answer: The branch of chemistry that studies organic substances came to be called organic chemistry.
Group 3. What chemical element is necessarily included in the composition of organic substances?
Answer:
All organic substances contain the chemical element carbon.
Question 4.
What other definition of organic chemistry can be given?
Answer.
Organic chemistry is the chemistry of carbon compounds(write the wording in your notebook).
Question 5.
Besides carbon, what chemical element is included in organic matter?
Answer.
In addition to carbon, all organic substances contain the chemical element hydrogen. May also include O, S, N and other elements(write the signs of chemical elements on the board).
Question 6.
Which chemical property may be common to organic substances?
Answer.
All organic matter burns.
What substances are formed when organic substances burn?carbon dioxide and water (writing in a notebook in words and reaction ) conclusion about what was said
Guys, another interesting property of organic substances is the ability to char and decompose when heated. Let's take examples from life. What happens to foods containing starch and protein?Coal is formed.
If you overcook potatoes, pancakes, pancakes, or bread, the starch contained in the potatoes and flour becomes charred. When eggs or meat burn, the protein contained in these foods is charred.
Guys, what happens if you put table salt and sugar on a hot frying pan?
Let's conduct an experiment (instructions) Why do you think table salt and sugar behave differently when heated?
These substances have different crystal lattices.
What is the crystal lattice of table salt and sugar?In table salt NaCl is an ionic crystal lattice, and in sugar C 12 N 22 ABOUT 11 - molecular.
What type chemical bond characteristic of organic substances.Covalent polar chemical bond ) conclusion about what was said
Guys, let's write it downsigns of organic substances:
1) contain carbon;
2) burn and (or) decompose to form carbon-containing products;
3) covalent chemical bond;
4) molecular crystal lattice
| Reagents | Description or outline of the experience | Equipment |
| Copper oxide (II) CuO, granulated sugar, lime water | Lime water A mixture of sugar and copper (II) oxide | 2 test tubes, a stopper with a gas outlet tube, a tripod, an alcohol lamp, matches, asbestos mesh, dry fuel. |
| Precautions | Progress of the experiment | Notes |
| First, heat the entire test tube, and then its end. At the end of the experiment, remove the gas outlet tube from the limewater, then turn off the alcohol lamp. | Pour 0.2 g of granulated sugar and 2-3 times more copper oxide into a dry test tube (II), mix everything thoroughly and start heating. Record your observations. 1. What gas caused the limewater to become cloudy? Write the reaction equation. 2. What substance was formed on the cold walls inside the test tube? 3. What substance was formed from copper oxide (II)? Write the reaction equation between copper oxide (II) and carbon. Draw a conclusion about whether granulated sugar belongs to organic or inorganic compounds.) conclusion about what was said | Stop the experiment as soon as the lime water becomes cloudy. |
In the excited state, the valence of carbon is 4. And in all organic compounds, the carbon atom is always tetravalent.
The simplest formula in organic chemistry CH4 - methane. We use structural formulas.(Making up a structural formula - grade 11) C lied3
Valence is indicated by dashes: one dash corresponds to the unit of valence of an atom of a chemical element.
What organic substances studied in the lesson can be added to the “cluster” we have compiled?oil, candle, propane, glucose, butane, dichloromethane, acetic acid, acetylene, ethane, etc.
What is the valence of carbon in organic compounds?In organic compounds, carbon is always tetravalent
What chemical property is common to organic compounds?Many organic substances burn or decompose when heated without exposure to air.
What is the importance of organic matter in society?These are food, clothing, shoes, synthetic materials, polymers, energy resources, medicines, synthetic detergents, various paints, varnishes, dyes, toothpaste, shampoos, etc.
What effect do organic substances have on the human body? (Roxana, Rita)
III . Reflection
Guys, today we learned that organic chemistry is studied. What chemicals are called organic. The concept of valency of chemical elements was revealed. We examined the importance of organic substances and showed, with the help of additional literature, the negative impact of some of them on the environment.
Have we answered the questions we asked at the beginning of the lesson?
Guys, you have tests on the topic you studied on your table. Let's test your knowledge (2-3min)
Choose one correct answer.C
lead 4
1. What does organic chemistry study?
A) All compounds formed in living organisms.
B) Compounds of carbon with hydrogen.
B) Carbon compounds, with the exception of oxides, carbides, salts.
2. Which compound is classified as organic?
A) Acetic acid.
B) Baking soda.
B) Table salt.
3. By 2005, the number of known organic compounds is......
A) About 1 million
B) About 15 million
B) About 2 million
4. What are the names of compounds consisting only of hydrogen and carbon?
A) Organic substances.
B) Minerals.
B) Hydrocarbons.
5. Mass fraction carbon in methane CH4 equal to
A) 75%
B) 80%
B) 25%
C lead 5
IV . Summing up
Guys, everyone has atable “Reflection on the student’s activities in the lesson.”
I ask you to fill out the table and give it to me.
V . Homework C lead 6
Study § 48+ notes, *task No. 1, 2 p. 216 (for everyone), *task No. 36 p. 216 for in-depth study.
Now imagine what will happen if organic matter disappears.
There will be no more wooden objects, no more ballpoint pens, no book bags, no more books and notebooks made from organic matter - cellulose. There will be no linoleum in the classroom; only metal legs will remain from the desks. Cars will not drive on the street - there is no gasoline, and only metal parts will remain from the cars themselves. Computer and TV cases will disappear. Pharmacies will be out of most medications, and there will be nothing to eat (all food also consists of organic compounds). There will be nothing to wash your hands with and nothing to put on yourself, because soap and cotton, wool, synthetic fibers, leather and leather substitutes, fabric dyes are all derivatives of hydrocarbons. And there will be no one to look at this world - all that will remain of us is salt water Yes, a skeleton, because the organisms of all living beings consist of organic compounds.
Now you understand the role of organic compounds in nature and our lives
C lead 6 this is interesting
While you are reading this article, yourseyes use organic compound- retinal , which converts light energy into nerve impulses. While you are sitting in a comfortable position,back muscles maintain correct posture thanks tochemical breakdown of glucose with the release of the required energy. As you understand,The gaps between nerve cells are also filled with organic substances - mediators (or neurotransmitters) that help all neurons become one. And this well-coordinated system works without the participation of your consciousness! Only organic chemists understand as deeply as biologists how intricately man is created, how logically internal systems organs and their life cycle. It follows that the study of organic chemistry is the basis for understanding our life! And high-quality research is the way to the future, because new drugs are created primarily in chemical laboratories.
Self-analysis of the lesson
teacher of chemistry and biology Utkina A.I.
The lesson was held in the 9th grade of the Proletarskaya Secondary School.
Subject lesson "» . The class size is standard, average in its abilities, six students are assigned to the 7th type of education. Therefore, I set the main developmental goal to enable children to be active participants educational process, through including them in resolving educational problem situations to develop their logical thinking and maintaining attention through shifts educational activities and reflection on individual stages of the lesson.
Lesson "Introduction to Organic Chemistry"is the first lesson in the transition to the study of organic chemistry and is intended to give general overview and place the main emphasis and concepts. This is especially important since we are starting a new section in chemistry, “Organic Compounds,” for which 10 hours are allotted.
Lesson type - a lesson in learning new material
Lesson location in curriculum - lesson on introducing new material.
Level of lesson delivery: predicting ways to transfer students to the result specified by the learning goals based on feedback and overcoming possible difficulties in work.
Main goal (for students) - in the process of practical activity, based on an analysis of the composition of substances, divide substances into organic and inorganic and confirm the prediction experimentally. Main task associated with the formation of activity experience - enrichment personal experience student through an educational experiment and establishing the properties of organic substances by logical means.
The topic and content of the lesson predetermined the formulation of educational tasks:
- To cultivate neatness, hard work, patriotic, aesthetic and moral qualities.
- Continue the formation of tolerance through the implementation of certain types of collective work: updating knowledge, practical assignments, laboratory experience.
These tasks were solved in combination at all stages of the lesson. All stages are logically interconnected:
Organizational moment set up students to achieve the goal: the goal of the lesson was communicated, the predicted result was announced, and motivation to realize the goal. All this made it possible to include students in the course of the lesson.
At the second stage of the lesson, updating knowledge and analyzing information, a differentiated approach was used: 11th grade students completed the task of the interaction of sugar with copper oxide and lime water. The task of systematizing and integrating knowledge (work - searching and deploying information) and finding a creative solution (task of drawing up reaction equations). Students of intermediate level of knowledge completed analytical tasks oncombustion of inorganic and organic substances. During my work, I carried out the necessary consultations in order to create a “success situation”.
Most of educational material I preferred to give deductively. To do this, students were asked to answer questions, the answers to which previously acquired knowledge were voiced, and at the same time we began to study new material. This allowed me to use such important principles of didactics as scientific approach and accessibility.
Interdisciplinary connections have been implemented through the use of materials from biology and technology “This is interesting” during the presentation. Observing the principle of systematicity, we walked from the known to the unknown (the students knew the substances, but could not explain them), from simple to complex. It was impossible to do without a demonstration experiment, since it contributed to the development of skills in conducting a chemical experiment.
To check the level of knowledge acquisition, students completed a test control.
The following teaching methods were used during the work:
- Verbal (the role of organic substances for humans, etc.);
- Visual (demonstration of slides, test);
- Problem-search (individual and group tasks to predict the properties of substances)
- Heuristic
- Research (experiment);
- Laboratory method.
The combination of these methods in the lesson showed high efficiency. Optimal performance of students in the lesson was achieved by alternating types of learning activities at different stages of the lesson and in a calm, friendly environment. All this ensured that students were not overloaded.
Instructions for completing homework were given special attention, as it requires an understanding of the topic as a whole.The final stage was the assessment of the lesson results, summing up and commenting on the students’ activities.
The purpose of the lesson is fulfilled, the tasks are realized.
The topic “Subject of organic chemistry” is offered for study. The role of organic substances in human life." The teacher covers the question of why there was a need to divide substances into organic and inorganic. Next, he tells students about the carbon cycle in nature, defines organic substances, and explains what hydrocarbon derivatives and organogens are. At the end of the lesson, the teacher will reveal the role of organic chemistry in our lives.
Topic: Introduction to organic chemistry
Lesson: Subject of organic chemistry.The role of organic substances in human life
By the beginning of the 21st century, chemists had isolated millions of substances in their pure form. At the same time, more than 18 million compounds of carbon and less than a million compounds of all other elements are known.
Carbon compounds are mainly classified as organic compounds.
Substances began to be divided into organic and inorganic from the beginning of the 19th century. Organic substances were then called substances isolated from animals and plants, and inorganic were substances extracted from minerals. It is through the organic world that the main part of the carbon cycle in nature passes.
From compounds containing carbon to inorganic traditionally include graphite, diamond, carbon oxides (CO and CO 2), carbonic acid (H 2 CO 3), carbonates (for example, sodium carbonate - soda Na 2 CO 3), carbides (calcium carbide CaC 2), cyanides (potassium cyanide KCN), rhodanide (sodium rhodanide NaSCN).
A more precise modern definition: organic compounds are hydrocarbons and their derivatives.
The simplest hydrocarbon is methane. Carbon atoms can combine with each other to form chains of any length. If in such chains carbon is also bonded to hydrogen, the compounds are called hydrocarbons. Tens of thousands of hydrocarbons are known.
Models of molecules of methane CH 4, ethane C 2 H 6, pentane C 5 H 12
Hydrocarbon derivatives are hydrocarbons in which one or more hydrogen atoms are replaced by an atom or group of atoms of other elements. For example, one of the hydrogen atoms in methane can be replaced by chlorine, or an OH group, or an NH 2 group.
Methane CH 4, chloromethane CH 3 Cl, methyl alcohol CH 3 OH, methylamine CH 3 NH 2
Organic compounds, in addition to carbon and hydrogen atoms, may include atoms of oxygen, nitrogen, sulfur, phosphorus, and less commonly halogens.
To appreciate the importance of the organic compounds that surround us, let’s imagine that they suddenly disappeared. No wooden objects, books or notebooks, no book bags or ballpoint pens. The plastic casings of computers, televisions and other household appliances have disappeared; telephones and calculators are gone. Without gasoline and diesel fuel Transport has stopped, most medicines are missing and there is simply nothing to eat. No detergents, clothes, and you and me too...
There are so many organic substances because of the way carbon atoms form chemical bonds. These small atoms are capable of forming strong covalent bonds with each other and with nonmetal organogens.
In the ethane molecule C 2 H 6 there are 2 carbon atoms bonded to each other, in the pentane molecule C 5 H 12 there are 5 atoms, and in the well-known polyethylene molecule there are hundreds of thousands of carbon atoms.
Studies the structure, properties and reactions of organic substances organic chemistry.
Chemistry. 10th grade. Profile level: textbook for general education Institutions / V.V. Eremin, N.E. Kuzmenko, V.V. Lunin. – M.: Bustard, 2008. – 463 p.
ISBN 978-5-358-01584-5
Chemistry. 11th grade. Profile level: academic. for general education Institutions / V.V. Eremin, N.E. Kuzmenko, V.V. Lunin. – M.: Bustard, 2010. – 462 p.
Khomchenko G.P., Khomchenko I.G. Collection of problems in chemistry for those entering universities. – 4th ed. – M.: RIA “New Wave”: Publisher Umerenkov, 2012. – 278 p.
Tutorial on the Internet
Samara State University.
Department of Organic, Bioorganic and Medical Chemistry
IXClass
Topic: “GENERAL VIEWS”ABOUT ORGANIC SUBSTANCES"
(Lesson on learning new material)
Lesson format: teacher's story and demonstration of samples and models of organic substances.
In connection with the transition to concentric programs in grade IX, the basics of organic chemistry are studied and ideas about organic substances are laid. Below is the development of a two-hour lesson that was taught in class IX after studying the topic “Carbon and its compounds”.
Lesson objectives: form an idea of the composition and structure of organic compounds, their distinctive features; identify the reasons for the diversity of organic substances; continue to develop the ability to compose structural formulas using the example of organic substances; form an idea of isomerism and isomers.
Preliminary homework: remember how a covalent bond is formed in molecules of inorganic substances, how its formation can be graphically shown.
Materials and equipmentTo lesson: samples of organic substances (acetic acid, acetone, ascorbic acid, sugar - in factory packages with labels, paper, candle, spirit lamp with alcohol, dry fuel (urotropine), oil; samples of products made of plastic and synthetic fibers (rulers, pens, bows, buttons, flower pots, plastic bags, etc.); matches, porcelain cup, crucible tongs. Ball-and-stick models of methane, ethylene, acetylene, propane, butane, isobutane, cyclohexane. On each student desk there is a bathtub with ball-and-stick models.
Lesson progress:
I. The teacher tells how the term “organic substances” originated.
Until the beginning of the 19th century, substances were divided by origin into mineral, animal and plant. In 1807 Swedish chemist J. Ya. Berzelius introduced the term “organic substances” into science, combining substances of plant and animal origin into one group. He proposed to call the science of these substances organic chemistry. At the beginning of the 19th century, it was believed that organic substances cannot be obtained under artificial conditions; they are formed only in living organisms or under their influence. The fallacy of this idea was proven by syntheses of organic substances in laboratory conditions: in 1828, the German chemist F. Wöder synthesized urea, his compatriot A. V. Kolbe obtained acetic acid in 1845, in 1854 the French chemist P. E. Berthelot - fats, in 1861 by Russian chemist A.M. Butlerov - a sugary substance. (This information is pre-written on the board and closed; during the message, the teacher opens this recording.)
It turned out that there is no sharp boundary between organic and inorganic substances; they consist of the same chemical elements and can be converted into each other.
Question: On what basis are organic substances classified as a separate group, what are their distinctive features?
The teacher invites students to try to figure this out together.
II. The teacher shows samples of organic substances, names them and, if possible, indicates the molecular formula (for some substances the formulas are written in advance on the board and closed during the demonstrationwalkie-talkie, these entries open): acetic acid C 2 H 4 O 2 acetone C 3 H 6 O, ethyl alcohol (in an alcohol lamp) C 2 H 6 O, dry fuel methenamine C 6 H 12 N 4, vitamin C or ascorbic acid C 6 H 8 O 6, sugar C 12 H 22 O 11, paraffin candle and oil, which contain substances with general formula C X N U, paper consisting of cellulose (C 6 H 10 O 5) p.
Questions: What do you notice in common in the composition of these substances? What chemical property can you assume for these substances?
Students answer that all of the compounds listed include carbon and hydrogen. They are believed to be on fire. The teacher demonstrates the combustion of hexamine, a candle and an alcohol lamp, draws attention to the nature of the flame, successively introduces a porcelain cup into the flame of the alcohol lamp, hexamine and a candle, and shows that soot is formed from the candle flame. Next, the question of what substances are formed during the combustion of organic substances is discussed. Students come to the conclusion that carbon dioxide or carbon monoxide, pure carbon (soot, soot) can be formed. The teacher reports that not all organic substances are capable of burning, but they all decompose when heated without access to oxygen and become charred. The teacher demonstrates the charring of sugar when heated. The teacher asks to determine the type of chemical bond in organic substances based on their composition.
Next, students write down in their notebooks signs of organic matterentities: 1. Contain carbon. 2. Burn and (or) decompose to form carbon-containing products. 3. The bonds in molecules of organic substances are covalent.
III. The teacher asks students to formulate a definition according to
concept "organic chemistry". The definition is written down in a notebook. Orga
nic chemistry- the science of organic substances, their composition, structure,
properties and methods of production.
Syntheses of organic substances in laboratory conditions accelerated the development of organic chemistry; scientists began to experiment and obtain substances that are not found in nature, but correspond to all the characteristics of organic substances. These are plastics, synthetic rubbers and fibers, varnishes, paints, solvents, medicines. (The teacher demonstrates products made from plastics and fibers.) These substances are not organic in origin. Thus, the group of organic substances has expanded significantly, but the old name has been retained. In the modern understanding, organic substances are not those that are produced in living organisms or under their influence, but those that correspond to the characteristics of organic substances.
IV. The study of organic substances in the 19th century encountered a number of
difficulties. One of them is the “unclear” valency of carbon. Yes, on
For example, in methane CH 4 the valence of carbon is IV. In ethylene C 2 H 4, acetylene
C 2 H 2, propane C 3 H 8, the teacher suggests determining the valency yourself
students. Students find the valencies II, I and 8/3, respectively. Semi
the given valences are unlikely. So, to organic substances
methods of inorganic chemistry cannot be used. In fact, in the building
there are organic substances peculiarities: the valence of carbon is always IV,
carbon atoms are connected to each other into carbon chains. Teacher
proposes to construct structural formulas of these substances. Students in
construct structural formulas in notebooks and put them on the board:
For comparison, the teacher demonstrates ball-and-stick models of these substances.
After this, the teacher asks to graphically depict the formation of co-
valence bonds in methane, ethylene and acetylene molecules. Images
put on the board and discussed. ,
V. The teacher draws students' attention to the periodic table.
More than 110 chemical elements have now been discovered, all of them included in
composition of inorganic substances. About 600 thousand inorganic compounds are known. The composition of natural organic substances includes a few elements: carbon, hydrogen, oxygen, nitrogen, sulfur, phosphorus, and some metals. IN lately synthesize organic elemental substances, thereby expanding the range of elements that make up organic substances.
Question: How many organic compounds do you think are currently known? (Students name the expected number of knownorganic substances. Usually these numbers are underestimated compared to actualtical amount of organic substances.) In 1999, the 18 millionth population was registered organic matter.
Question: What are the reasons for the diversity of organic substances? Students are encouraged to try to find them in what is already known about the structure of organic substances. Students name reasons such as: carbon compounds in chains of different lengths; connection of carbon atoms by simple, double and triple bonds with other atoms and with each other; many elements that make up organic substances. The teacher gives another reason - the different nature of carbon chains: linear, branched and cyclic, demonstrates models of butane, isobutane and cyclohexane.
Students write in their notebooks: The reasons for diversity are organicski connections.
1. Connection of carbon atoms in chains of different lengths.
Formation of single, double and triple bonds by carbon atoms
zey with other atoms and with each other.
Different character of carbon chains: linear, branched,
cyclical.
Many elements that make up organic substances.
There is another reason. (It is necessary to leave a place for its recording in the textfor the sake of.) Students must find it themselves. To do this, you can do laboratory work.
VI. Laboratory work.
Students are given balls and rods: 4 black balls with 4 holes each - these are carbon atoms; 8 white balls with one hole each - hydrogen atoms; 4 long rods for connecting carbon atoms to each other; 8 short rods - for connecting carbon atoms with hydrogen atoms.
Assignment: using all the “building material”, build a model of an organic substance molecule. Draw the structural formula of this substance in your notebook. Try to do as much as possible different models from the same " building material».
Work takes place in pairs. The teacher checks the correct assembly of models and depiction of structural formulas, and helps students who have difficulties. 10-15 minutes are allotted for work (depending on the success of the class), after which the structural formulas are put on the board and the following questions are discussed: What do all these substances have the same? How are these substances different?
It turns out that the composition is the same, the structure is different. The teacher explains that such substances, the composition of which is the same, but the structure and therefore properties are different, are called isomers. Under structure substances implies the order of connection of atoms, their relative arrangement in molecules. The phenomenon of the existence of isomers is called isomeriya.
VII. Definitions of the concepts “chemical structure”, “isomers” and “isomerism” are written down by students in a notebook after the structural formulas of isomers. And in reasons for the diversity of chemicals is entered fifthpoint - the phenomenon of isomerism of organic compounds.
The ability to construct structural formulas of isomers is practiced using the following examples: C 2 H 6 O (ethanol and dimethyl ether), C 4 H 10 (butane and isobutane). Using these examples, the teacher shows how to write an abbreviated structural formula:
The teacher suggests constructing isomers of the composition C 5 H 12) if it is known that there are three of them. After putting all the isomers on the board, the teacher draws students’ attention to the method of constructing isomers: decreasing the main chain each time and increasing the number of radicals.
Homework: learn notes in a notebook, construct isomers of the composition C 6 N M (there are 5 of them).
In chemistry class we learn a lot of new and interesting things. The assistants have lesson notes on your desks; take notes in them as the lesson progresses.
- Carbon is called the "element of life"
What are the oxidation states of carbon?
We will call these modulo numbers VALENCE.
Inorganic chemistry studies substances of inanimate nature - minerals. What do we call substances of living nature - plant and animal origin, contained in living organisms?
The science that studies such substances is organic chemistry.
1 slide
The topic of the lesson is “Introduction to the course of organic chemistry.”
Lesson objectives: 1. Introduction to a new section of chemistry - organic chemistry.
2. Study the composition, structure, properties of substances.
3. Necessary for ____________
2 slide
The concept of OB was first introduced into science by J.Ya. Berzelius.
Is there a sharp boundary between organic and inorganic substances?
3 slide
At one time, foreign and Russian scientists in laboratories synthesized organic substances from inorganic substances.
By what criteria can organic substances be combined?
4 slide
Here are the names and formulas of organic substances. What are the similarities?
What type of chemical bond, melting point?
5 slide
Let's conduct an experiment: charring sugar
Let's write point 3.
Several hundred inorganic substances are known
thousand, and how many are organic?
6slide
Why so many?
Demonstrating: Pens, rulers - what substance are they made of? This is also an organic substance synthesized in the laboratory; it does not exist in nature. but the name “organic” remained.
7 slide
As a result of the synthesis, fibers, varnishes, paints, and other substances can also be obtained.
What conclusion can be drawn: what are the similarities and what are the differences between OM and inorganic ones?
3.
Is it possible to apply the laws and concepts of inorganic chemistry to chemical agents?
For example, the concept of valence?
On the board are the OB formulas:
Task: Establish the valence of carbon.
CH 4 C 2 H 4 C 2 H 2 C 3 H 8
Valence is “incomprehensible”...
Scientists assumed the valency of carbon to be IV. Assignment: Make up structural formulas of substances.
N N N N N N
/ / / / / /
N-S-N N-S = C – N N-S=
S-N N-S –S –S –N
/ / / /
N N N N
Conclusion: observing valency, in addition to a simple (single) bond, double and triple bonds appear, namely between carbon atoms.
8slide
Let us write down the reasons for diversity:
To understand the meaning of point 5, let’s turn to the letters: FLASK - make a new word from the same letters.
What's the difference?
What are the similarities?
The quantitative and qualitative composition is the same, but the sequence of compounds, that is, the structure is different.
In chemistry, this phenomenon is called ISOMERIA.
4.
Slide 9
Laboratory work. Assemble the molecule as in the picture and find the corresponding formula on the slide.
Report: 1 gr. 2 gr. 3 gr. 4 gr. 5 gr.
So, what are the similarities and differences between the isomers?
10 slide
Welcome to the world of organic chemistry.
5. Lesson summary:
Which section of chemistry did you familiarize yourself with?
What is she studying?
Why is it necessary?
Testing:
- Valency of carbon in OM?
- The name of the scientist who introduced the concept of OB?
- A phenomenon in which the qualitative and quantitative composition is the same, but the sequence of the compound is different?
- What is the order of atoms in a molecule?
- What is the method for obtaining new substances called? We check it ourselves.
There are no errors at all or just one, then raise your hand.
6.
11slide
Compose isomers of composition C 6 N 14 (there are 5 of them)