This lesson is designed for students of the 10th grade of the natural and mathematical profile.”.

Lesson objectives:

Show the dependence of the geometry of molecules on the type of hybridization of electron orbitals, and the properties of substances on the geometry of molecules.

Equipment: PC, multimedia projector, screen, electronic presentation. Ball-and-stick models of molecules of methane, pentane, graphite, diamond, ethylene, acetylene, models of molecules made from balloons, geometric models of a tetrahedron and a triangular pyramid. Demonstration table "Allotropic modifications of carbon", photographs depicting molecules and crystals, students' reports, a portrait of L. Pauling.

Lesson plan

III.

sp 3 __ hybridization;

sp 2 __ hybridization;

sp - hybridization.

Task for the lesson: repeat the hybridization of the electron orbitals of the carbon atom, properties chemical bond. 1 student cooks electronic presentation“Life and work of L. Pauling”.

Board decoration

Lesson progress

I. Organizing time . Slide number 1.

II. Homework conversation (6 min). Slide number 2, formulas of substances on the board.

What properties covalent bond did we learn in the last lesson? (length, E, strength, saturation)

What is bond length and what does it depend on? (depending on the size of the atom and the multiplicity of bonds)

What is bond energy and what does it depend on? (the amount of energy needed to break the bond; depends on the strength of the bond)

What is bond strength and what does it depend on? (on which connection is ?, or ?, and which clouds overlap - hybrid or non-hybrid)

How are the properties of a covalent bond related? (the longer the length, the lower the strength and energy)

How does the bond length change in hydrogen halide molecules (see on the board - 1st column) and why? (increases as the size of the atom increases)

Which of the given connections (on the board) is the strongest? (HF)

Hydrogen halides are dissolved in water to form acids. Which of these acids is the strongest and why? (HJ, because acidity is the ability to release H + , HJ has the weakest bond)

Which acid is the weakest? (HF - hydrofluoric acid, dissolves glass)
Teacher: The properties of a substance depend on the size of the atoms that form them.

How does the bond strength change in a series of hydrocarbons (see the 2nd column on the board) and what does it depend on? (from top to bottom, the bond strength increases, because the multiplicity increases and the length decreases)

How does this affect the properties of these substances? (for alkanes having only sigma bonds, substitution reactions are characteristic, for alkenes having sigma and pi bonds - additions, and for alkynes - addition reactions and substitution reactions of hydrogen atoms in the triple bond)

Using the example of molecules of simple substances chlorine, oxygen, nitrogen (see on the board - 3rd column), explain how the structure of their molecules affects their properties. (free chlorine is not found - a single bond, oxygen in the air 21% - a double bond, nitrogen in the air 78%, an inert substance - a triple bond)
Teacher : Properties of organic and Not organic matter depend on the bond strength.

How bond saturation affects the properties of substances (see on the board - 4th column) (methane does not have unsaturated bonds, ammonia and water have unsaturated bonds, therefore they are dipoles).
teacher b: The properties of substances depend on the properties of the covalent bond.

II. Studying new topic

The influence of the laws of nature and structural features of molecules on the order and beauty of the world around

Slides ## 3-20

Essence of hybridization of electron orbitals, its mechanism.

Conversation. What is hybridization, what precedes it, what does it contribute to, why is there a gain in energy? What types of hybridization of the carbon atom did we meet in grade 10?

Demonstration of the hybridization mechanism.

Slides ## 21-24

Conclusion. The concept of hybridization is used to explain the geometry of molecules. During hybridization, hybrid clouds are arranged in space in such a way that the energy of their interaction is minimal. The determining factors in the geometry of the molecule are?-bonds.

slide number 24

From the history of the issue. Pauling L. - the great chemist of the twentieth century, his merits in the study and description of the structures of molecules.

Demonstration of the presentation “Life and work of L. Pauling” (homework)

Conclusion . We should be proud of the fact that there are wonderful world-famous chemists. These are Lomonosov M.V. - a scientist-encyclopedist, Mendeleev D.I. - the creator of the Periodic Law, Borodin A.P. - a chemist and composer, Butlerov A.M. - the creator of the theory of structure organic compounds, Lebedev S.V. - the creator of 1 artificial rubber in Russia and many others who contributed huge contribution in the development of chemical science. But we also have to treat scientists of other countries with great respect, and among them is Linus Pauling, who is a world-famous scientist, and every educated person should know about him.

The geometry of molecules of organic and inorganic substances, due to:

sp 3 __ hybridization;

sp 2 __ hybridization;

sp - hybridization.

heuristic conversation. Using the example of the structure of molecules of organic substances (hydrocarbons) and inorganic substances (compounds of silicon, nitrogen, oxygen, boron, beryllium; allotropic modifications of carbon), the teacher shows the universality of the concept of “hybridization” and the dependence of the geometry of molecules on hybridization, and the properties of substances on the geometry of molecules. During the conversation, students get acquainted with the geometry of the molecules of inorganic substances and the influence of unshared electron pairs on their properties.

Slides ## 25-36.

Anchoring

Conversation. Generalization of knowledge on the topic. Filling in the table.

slide number 37.

Frontal conversation on questions.

Slides ## 38-41.

Summing up the lesson

The world of molecules is beautiful and amazing. The properties of substances depend on the structural features of the molecules. And maybe someday, looking at falling snowflakes or a snow pattern on glass, or a diamond on your hand, you will remember this lesson, our school and understand that we teachers did everything to instill in your souls a sense of beauty. And I really want you to keep these feelings and pass them on to your children. For us teachers, this will be the best reward.

Slide number 42.

IV. Homework : §3.3 Notebook entries

Application No. 1

3. Learning a new topic.

It remains for us to consider one more property of a covalent bond - directionality. It is this property of the covalent bond that determines the geometry of the molecule, i.e. location of sigma bonds in space. To explain the direction of the covalent bond in polyatomic molecules, the hybridization model of electron orbitals proposed by L. Pauling in 1931 is used.

Lesson topic : Hybridization of electron orbitals. Geometry of molecules .

Lesson Objectives:

To reveal the universal nature of the hybridization process for organic, complex inorganic substances and allotropic modifications of carbon.

Show the dependence of the geometry of molecules on the type of hybridization of electron orbitals, and the properties of substances on the geometry of molecules.

To draw students' attention to the influence of the fundamental laws of nature and structural features of molecules on the existing order and beauty in the world.

Lesson plan:

Essence of hybridization of electron orbitals, its mechanism.

From the history of the issue. Pauling L. - the great chemist of the twentieth century, his merits in the study and description of the structures of molecules.

The geometry of molecules of organic and inorganic substances, due to:

1. sp 3 __ hybridization;

   sp 2 __ hybridization;

   sp- hybridization.

Introduction to the topic : Before we start studying the first question of the plan, I would like to draw attention to the epigraph of the lesson: "The reduction of many to one is the fundamental principle of beauty." This is a saying of the great ancient Greek philosopher and mathematician Pythagoras. What is the meaning of this expression? The world is beautiful and amazing, and it was formed as a result of the joint action of many fundamental laws of nature, such as the law of conservation of mass and energy, the law of minimum energy, the law gravity, the law of action natural selection, symmetry laws and other laws(Slide number 4).When we see the manifestation of symmetry in the bodies of living nature, we involuntarily experience a sense of satisfaction with the general order that reigns in nature(Slides ##4-6).Even what they produce has a certain, correct structure.(Slide number 7).

And the shells of the simplest organisms are beautiful not only for beauty, but this is the result of the laws of universal gravitation and the laws of natural selection - these are adaptations to the aquatic habitat(Slide number 8).Even such formidable organisms as viruses, a transitional form between inanimate and living, have a special regularity in structure, and by studying these features, you can find ways to deal with them.(Slide number 9).And in the bodies of inanimate nature, in crystals, we see a strict order in their structures(Slide number 10-12).But behind this orderliness lies a deeper order.order in molecules and atoms, by which these bodies are formed. Most likely, the structure of snowflakes would not be so perfect if the water molecule did not have a certain symmetry.(Slide number 13),and would not be connected by hydrogen bonds in ice crystals in the form of hexagons(Slide number 14).And supernatural properties would not be attributed to a diamond (slide number 15),and the ancient warriors would not have worn it near the heart, and it would not have been the hardest natural substance, if the carbon atoms that form it did not have an amazing regularity in space. We see order and beauty in a wide variety of molecules:(Slide number 16)and in the chlorophyll molecule, without which such an important process as photosynthesis is not possible,(Slide number 17)and in a protein molecule, the secondary structure of which is built according to the principle of complementarity and is supported by hydrogen bonds.(Slide number 18)And also in the stearic acid molecule, the insolubility of which is determined by the large hydrocarbon radical, (Slide number 19)and in the DNA molecule - the carrier of hereditary information about the structure of the cell, and in the hemoglobin molecule, which performs the respiratory function in many living organisms.

Thus, we can conclude:(Slide number 20)all order and beauty in the world depend on the peculiarities of the structure of molecules, on their geometry. It is in this amazing and beautiful world of molecules that I invite you

Option 1

sp 2

1. C 2 H 4 , CH 4 , C 3 H 6 ;

   C 2 H 4 , BCl 3 , C 6 H 6 ;

   BH 3 , CH 4 , BeCl 2 ;

   NH 3 , SiH 4 , H 2 Oh

Which molecule has a linear formula?

1. BeCl 2 ;

   BCl 3 ;

   C(graphite);

   C (diamond).

Electronic orbitals at an angle of 109 ° 28 'are located in the molecule

1. C (carbine);

   C 2 H 2 ;

   C (diamond);

   C 2 H 4 .

flat triangular shape molecules has

1. C 2 H 2 ;

   BCl 3 ;

   CH 4 ;

   NH 3 .

Single length C-C connection in alkanes is

1. 0.134 nm;

   0.154 nm;

   0.120 nm;

   0.140 nm.

The phosphate anion has a tetrahedral structure. What type of hybridization is typical for the central atom of the anion?

1. sp;

   sp 2 d;

   sp 2 ;

   sp 3 .

"Hybridization of electron orbitals and the geometry of molecules"

Option 2

Select the formulas of compounds that have a similar direction due tosp 3 -hybridization of electron orbitals:

1. C 2 H 4 , CH 4 , C 3 H 6 ;

   C 2 H 4 , BCl 3 , C 6 H 6 ;

   BH 3 , CH 4 , BeCl 2 ;

   NH 3 , SiH 4 , H 2 Oh

Which molecule has a tetrahedral formula?

1. BeCl 2 ;

   BCl 3 ;

   C(graphite);

   C (diamond).

Electronic orbitals at an angle of 180° are located in the molecule

C (carbine);

C 2 H 2 ;

C (diamond);

C 2 H 4 .

The linear shape of the molecule is

1. 1. C 2 H 2 ;

      BCl 3 ;

      CH 4 ;

      NH 3 .

The length of a single C-C bond in a benzene molecule is

0.134 nm;

0.154 nm;

0.120 nm;

0.140 nm.

The nitrate anion has the shape of a flat triangle. What type of hybridization is typical for the central atom of the anion?

sp;

sp 2 d;

sp 2 ;

sp 3 .

Establish a correspondence between the formulas of substances and the types of hybridization of their central atom.

This lesson will help you get an idea about the topic “Geometry of molecules. The concept of the theory of hybridization. The universal nature of the hybridization process for organic, complex inorganic substances and allotropic modifications of carbon will be disclosed. You will learn about the dependence of the geometry of molecules on the type of hybridization of electron orbitals and the properties of substances on the geometry of molecules.

Topic: Introduction to organic chemistry

Lesson: Geometry of molecules. The concept of the theory of hybridization

on the example of molecules with single bonds

External level carbon atom in the ground (unexcited) state is described by the formula 2s 2 2p 2 or by the scheme:

This building contains the preconditions for a peculiar symmetry There are exactly 4 orbitals for four electrons. Back in the middle of the 19th century, the German scientist Friedrich Kekule rightly suggested that in organic compounds the valency of carbon is four.

From the point of view of the electronic structure of the atom, this can be explained as follows:

One electron from the 2s-orbital "jumps" to the 2p-orbital, while the carbon atom goes into the so-called excited state:

Excited state of an atom carbon 2s 1 2p 3:

allows the carbon atom to form 4 covalent bonds by the exchange mechanism.

Three p-orbitals are traditionally depicted in the form mutually perpendicular each other “dumbbells”, and the s-orbital is in the form of a ball. The three p-electron bonds must be at 90° to each other and are significantly longer than the s-electron bond. But methane CH 4 is a symmetrical tetrahedron.

As early as 1874, many years before direct determination of the structure of molecules became possible, Jacob Henrik van't Hoff (1852-1911), as a student at Utrecht University, suggested that the carbon atom in compounds has a tetrahedral structure. The structure of the CH 4 methane molecule is a regular tetrahedron with a carbon atom in the center. Valence angles H-C-H bonds are equal to 109 about 28 '.

Simplified explanation: all orbitals of the outer level of carbon align in energy and shape, mix, i.e. "hybridize" to form identical hybrid orbitals. See fig. 1.

Rice. 1. Hybridization is the mixing of electron clouds during the formation of chemical bonds

Mixing one s-orbitals and three p-orbitals gives four sp 3-hybrid orbitals elongated at the corners of a tetrahedron with a C atom in the center. Carbon in methane is in a state of sp 3 hybridization. Rice. 2.

Rice. 2. The structure of methane

The structure of ammonia

In the same way, four orbitals of the nitrogen atom hybridize in ammonia molecule NH 3: The nitrogen atom has 5 electrons in its outer level. Therefore, on one sp 3 orbital there is a lone pair of electrons, and on the other three - electron pairs of N-H bonds. All four electron pairs are located at the corners of a distorted tetrahedron (the electron cloud of the lone pair is larger than that of the bonding pair). Rice. 3

Rice. 3. The structure of ammonia

The structure of water

An oxygen atom has 6 electrons in its outer level. Therefore, lone pairs of electrons are located on two sp 3 orbitals, and electron pairs are located on the other two O-H bonds. The molecule has an angular structure. Rice. 4.

Rice. 4. The structure of water

In such an analysis of the structure of molecules, it is important not to confuse the geometry of the arrangement of electron pairs in space and the geometry of chemical bonds. We see that in ammonia and water, not all electron pairs participate in the formation of chemical bonds.

The geometry of molecules or chemical bonds considers precisely the arrangement of atoms in space, without describing the arrangement of unshared electron pairs. The electron clouds of hybrid orbitals try to push each other as far as possible. If there are four clouds, then they will diverge at the corners of the tetrahedron, three - they will be located in a plane at an angle of 120 °.

The structure of the moleculeBF 3

The outer level of the boron atom has 3 electrons. When bonds are formed, boron, like carbon, goes into an excited state. One s- and two p-orbitals, which have electrons, hybridize, forming three identical sp 2 hybrid orbitals, located at the corners of an equilateral triangle with a boron atom in the center. Rice. 5

Rice. 5. Structure of three boron fluorides

Conclusion: The geometry of molecules considers the arrangement of atoms in space without describing the arrangement of lone electron pairs. So, the structure of a water molecule, consisting of three atoms, is not tetrahedral, but angular.

Summing up the lesson

You got an idea about the topic “Geometry of molecules. The concept of the theory of hybridization. The universal nature of the hybridization process for organic, complex inorganic substances and allotropic modifications of carbon was revealed. You learned about the dependence of the geometry of molecules on the type of hybridization of electron orbitals and the properties of substances on the geometry of molecules.

Bibliography

1. Rudzitis G.E. Chemistry. Basics general chemistry. Grade 10: textbook for educational institutions: a basic level of/ G. E. Rudzitis, F.G. Feldman. - 14th edition. - M.: Education, 2012.

2. Chemistry. Grade 10. Profile level: studies. for general education institutions / V.V. Eremin, N.E. Kuzmenko, V.V. Lunin and others - M.: Drofa, 2008. - 463 p.

3. Chemistry. Grade 11. Profile level: textbook. for general education institutions / V.V. Eremin, N.E. Kuzmenko, V.V. Lunin and others - M.: Drofa, 2010. - 462 p.

4. Khomchenko G.P., Khomchenko I.G. Collection of problems in chemistry for those entering the universities. - 4th ed. - M.: RIA "New Wave": Publisher Umerenkov, 2012. - 278 p.

Homework

1. Nos. 1-3 (p. 22) Rudzitis G.E. , Feldman F.G. Chemistry: Organic chemistry. Grade 10: textbook for educational institutions: basic level / G. E. Rudzitis, F.G. Feldman. - 14th edition. - M.: Education, 2012.

2. Why, having the same type of hybridization (which one?), do methane and ammonia molecules have different spatial structures?

3. What is the difference between the ground state of the carbon atom and the excited state?

This lesson was developed for students of the 11th grade of the physical and mathematical profile, who study chemistry under the program of Gabrielyan O.S. according to the textbook “Chemistry. Grade 11”, authors O.S. Gabrielyan et al. “Drofa” publishing house, 2006”.

The versatility of this development lies in the fact that it can be successfully used by teachers working on the programs of other authors in general education and specialized classes.

The work presented includes: technological map chemistry lesson in grade 11 with applications and electronic presentation. The originality of the work is determined by interactive inserts in the presentation, the use of information from the Internet, and at the same time independence from the Internet during the lesson. Illustrations included from various sources, their combination and method of presentation make it possible to fully implement interdisciplinary connections in the lesson, form a scientific worldview, and instill in students a love of beauty.

Development can be used as Toolkit. It is designed to help a novice chemistry teacher, as well as a teacher introducing information Technology in teaching chemistry.

Lesson objectives:

1. To reveal the universal nature of the hybridization process for organic, complex inorganic substances and allotropic modifications of carbon.
2. Show the dependence of the geometry of molecules on the type of hybridization of electron orbitals, and the properties of substances on the geometry of molecules.
3. To draw students' attention to the influence of the fundamental laws of nature and structural features of molecules on the existing order and beauty in the world.

Equipment: PC, multimedia projector, screen, electronic presentation. Ball-and-stick models of molecules of methane, pentane, graphite, diamond, ethylene, acetylene, models of molecules made from balloons, geometric models of a tetrahedron and a triangular pyramid. Demonstration table "Allotropic modifications of carbon", photographs depicting molecules and crystals, students' reports, a portrait of L. Pauling.

Lesson Plan

I. Essence of hybridization of electron orbitals, its mechanism.

II. From the history of the issue. Pauling L. - the great chemist of the twentieth century, his merits in the study and description of the structures of molecules.

III. The geometry of molecules of organic and inorganic substances, due to:

1. sp 3 __ hybridization;
2. sp 2 __ hybridization;
3. sp - hybridization.

Assignment for the lesson: repeat the hybridization of the electron orbitals of the carbon atom, the properties of the chemical bond. 1 student is preparing an electronic presentation "The life and work of L. Pauling."

Board decoration

I. Organizational moment. Slide number 1.

II. Homework conversation (6 min). Slide number 2, formulas of substances on the board.

1. What properties of a covalent bond did we study in the last lesson? (length, E, strength, saturation)
2. What is bond length and what does it depend on? (depending on the size of the atom and the multiplicity of bonds)
3. What is bond energy and what does it depend on? (the amount of energy needed to break the bond; depends on the strength of the bond)
4. What is bond strength and what does it depend on? (on which connection is ?, or ?, and which clouds overlap - hybrid or non-hybrid)
5. How are the properties of a covalent bond related? (the longer the length, the lower the strength and energy)
6. How does the bond length change in hydrogen halide molecules (see on the board - 1st column) and why? (increases as the size of the atom increases)
7. Which of the given connections (on the board) is the strongest? (HF)
8. Hydrogen halides are dissolved in water to form acids. Which of these acids is the strongest and why? (HJ, because acidity is the ability to give up H +, the weakest bond in HJ)
9. Which acid is the weakest? (HF - hydrofluoric acid, dissolves glass)
   Teacher: The properties of a substance depend on the size of the atoms that form them.
10. How does the bond strength change in a series of hydrocarbons (see the 2nd column on the board) and what does it depend on? (from top to bottom, the bond strength increases, because the multiplicity increases and the length decreases)
11. How does this affect the properties of these substances? (for alkanes having only?-bonds, substitution reactions are characteristic, for alkenes with?-bonds - additions, and for alkynes - addition reactions and substitution reactions of hydrogen atoms in the triple bond)
12. Using the example of molecules of simple substances chlorine, oxygen, nitrogen (see on the board - 3rd column), explain how the structure of their molecules affects their properties. (free chlorine is not found - a single bond, oxygen in the air 21% - a double bond, nitrogen in the air 78%, an inert substance - a triple bond)
    Teacher: The properties of organic and inorganic substances depend on the multiplicity of bonds.
13. How bond saturation affects the properties of substances (see on the board - 4th column) (methane does not have unsaturated bonds, ammonia and water have unsaturated bonds, therefore they are dipoles).
    teacher b: The properties of substances depend on the properties of the covalent bond.

II. Exploring a new topic

IV. Homework: §7, notes in a notebook, prepare for testing (see.

Lesson topic: Hybridization of electron orbitals and the geometry of molecules. Lesson objectives: 1. To reveal the universal nature of the concept of "orbital hybridization" not only for complex organic and inorganic substances, but also for allotropic modifications of carbon. 2. Show the dependence of the spatial structure of substances on the type, hybridization of electronic orbitals of the atoms of chemical elements that form these substances.

Stages of the lesson: 1. Actualization of students' knowledge on the topic "Hybridization of the orbitals of the carbon atom": - definition of hybridization; - types of hybridization on the example of molecules of methane, ethylene, acetylene. 2. Setting the goal of the lesson and its implementation - proof that hybridization is a universal concept, applicable not only to organic substances, but also to organic ones. 3. Homework.

Properties of a covalent bond: Saturation (determined by the valence capabilities of atoms), Orientation (determines the spatial structure of molecules, depending on what shape and direction in space electron clouds have when they overlap). Examples: Forming an s-p-sigma bond in H-F molecule. The S-electron of the hydrogen atom is spherical, and the unpaired p-electron of the fluorine atom is dumbbell-shaped. These electron clouds overlap along the line connecting the nuclei of hydrogen and fluorine atoms, forming a covalent bond. The hydrogen fluoride molecule has a linear structure:

Geometry of molecules of inorganic substances. SP 3 -hybridization of the outer electrons of the central atom on the example of a carbon tetrachloride molecule CCl 4 C * 2S 1 2P 3 bond angle Structure - tetrahedron

SP 3 hybridization on the example of an ammonia molecule. NH 3 N 2S 2 2P 3 Valence angle The presence of one non-bonding electron pair at the vertex of the tetrahedron changes the geometric structure of the molecule to a trigonal pyramid.

SP 2 - hybridization using the example of molecules of inorganic substances: BCl 3 - boron chloride B * 2S 1 2P 2 geometric configuration - a flat triangle SO 2 - sulfur dioxide S * 3S 2 3P 3 3D 1 angular structure, electrons involved in the formation of a pi bond are not hybridized.

Conclusions: Each type of hybridization corresponds to a certain geometric shape molecule defined by sigma bonds that create the rigid skeleton of the molecule. Hybridization requires an expenditure of energy (excitation) that is paid off by the formation of chemical bonds, therefore there must be more complete overlap with the orbits of another atom when a bond is formed. Atomic orbitals can participate in hybridization, which correspond to close energy levels: s and p of one outer and d of the outer and pre-outer layer. Stable hybridization is carried out in atoms of small periods i.e. orbitals must have a high electron density, as they move away from the nucleus, they become diffuse.

Chemistry lesson on the topic:

Hybridization of electron orbitals. Geometry of molecules

This lesson is designed for 11th grade students.sastudents studying chemistry under the program Gabrielyan O.S. according to the textbook “Chemistry. Grade 11”, authors O.S. Gabrielyan et al. “Drofa” publishing house, 2006”.

The versatility of this development lies in the fact that it can be successfully used by teachers working on the programs of other authors in general education and specialized classes.

The presented work includes: a technological map of a chemistry lesson in grade 11 with applications and an electronic presentation. The originality of the work is determined by interactive inserts in the presentation, the use of information from the Internet, and at the same time independence from the Internet during the lesson. Illustrations included from various sources, their combination and method of presentation make it possible to fully implement interdisciplinary connections in the lesson, form a scientific worldview, and instill in students a love of beauty.

The development can be used as a teaching aid. It is designed to help a novice chemistry teacher, as well as a teacher who introduces information technology in teaching chemistry.

Lesson objectives:

To reveal the universal nature of the hybridization process for organic, complex inorganic substances and allotropic modifications of carbon.

Show the dependence of the geometry of molecules on the type of hybridization of electron orbitals, and the properties of substances on the geometry of molecules.

To draw students' attention to the influence of the fundamental laws of nature and structural features of molecules on the existing order and beauty in the world.

Equipment: PC, multimedia projector, screen, electronic presentation. Ball-and-stick models of molecules of methane, pentane, graphite, diamond, ethylene, acetylene, models of molecules made from balloons, geometric models of a tetrahedron and a triangular pyramid. Demonstration table "Allotropic modifications of carbon", photographs depicting molecules and crystals, students' reports, a portrait of L. Pauling.

Lesson plan

I. Essence of hybridization of electron orbitals, its mechanism.

II. From the history of the issue. Pauling L. - the great chemist of the twentieth century, his merits in the study and description of the structures of molecules.

III. The geometry of molecules of organic and inorganic substances, due to:

sp 3 __ hybridization;

sp 2 __ hybridization;

sp - hybridization.

Task for the lesson: repeat the hybridization of the electron orbitals of the carbon atom, the properties of the chemical bond. 1 student is preparing an electronic presentation "The life and work of L. Pauling."

Board decoration

Lesson progress

I. Organizational moment . Slide number 1.

II. Homework conversation (6 min). Slide number 2, formulas of substances on the board.

What properties of a covalent bond did we study in the last lesson? (length, E, strength, saturation)

What is bond length and what does it depend on? (depending on the size of the atom and the multiplicity of bonds)

What is bond energy and what does it depend on? (the amount of energy needed to break the bond; depends on the strength of the bond)

What is bond strength and what does it depend on? (on which connection is ?, or ?, and which clouds overlap - hybrid or non-hybrid)

How are the properties of a covalent bond related? (the longer the length, the lower the strength and energy)

How does the bond length change in hydrogen halide molecules (see on the board - 1st column) and why? (increases as the size of the atom increases)

Which of the given connections (on the board) is the strongest? (HF)

Hydrogen halides are dissolved in water to form acids. Which of these acids is the strongest and why? (HJ, because acidity is the ability to release H + , HJ has the weakest bond)

Which acid is the weakest? (HF - hydrofluoric acid, dissolves glass)
Conclusion : The properties of a substance depend on the size of the atoms that form them.

How does the bond strength change in a series of hydrocarbons (see the 2nd column on the board) and what does it depend on? (from top to bottom, the bond strength increases, because the multiplicity increases and the length decreases)

How does this affect the properties of these substances? (for alkanes having only?-bonds, substitution reactions are characteristic, for alkenes with?-bonds - additions, and for alkynes - addition reactions and substitution reactions of hydrogen atoms in the triple bond)

Using the example of molecules of simple substances chlorine, oxygen, nitrogen (see on the board - 3rd column), explain how the structure of their molecules affects their properties. (free chlorine is not found - a single bond, oxygen in the air 21% - a double bond, nitrogen in the air 78%, an inert substance - a triple bond)
Conclusion : The properties of organic and inorganic substances depend on the multiplicity of bonds.

How bond saturation affects the properties of substances (see on the board - 4th column) (methane does not have unsaturated bonds, ammonia and water have unsaturated bonds, therefore they are dipoles).
Conclusion : The properties of substances depend on the properties of the covalent bond.

II. Exploring a new topic

№ pp

Conclusion . We should be proud of the fact that we live in Russia, where wonderful scientists and chemists of world renown lived and worked. These are Lomonosov M.V. - encyclopedic scientist, Mendeleev D.I. - creator of the Periodic Law, Borodin A.P. - chemist and composer, Butlerov A.M. - creator of the theory of the structure of organic compounds, Lebedev S.V. - creator 1 artificial rubber in Russia and many others who have made a great contribution to the development of chemical science. But we also have to treat scientists of other countries with great respect, and among them is Linus Pauling, who is a world-famous scientist, and every educated person should know about him.

heuristic conversation. Using the example of the structure of molecules of organic substances (hydrocarbons) and inorganic substances (compounds of silicon, nitrogen, oxygen, boron, beryllium; allotropic modifications of carbon), the teacher shows the universality of the concept of “hybridization” and the dependence of the geometry of molecules on hybridization, and the properties of substances on the geometry of molecules. During the conversation, students get acquainted with the geometry of the molecules of inorganic substances and the influence of unshared electron pairs on their properties.

IV. Homework : §7, notes in a notebook, prepare for testing (see. ).

List of sources used :

Gabrielyan O.S. etc. Handbook of the teacher. Chemistry. Grade 11: At 2 o'clock - M .: Bustard, 2003.

Ilchenko V.R. Crossroads of physics, chemistry and biology. – M.: Enlightenment, 1986.

CD" virtual school Cyril and Methodius” Biology lessons. Animals.

CD “Virtual School of Cyril and Methodius” Biology lessons. General biology.

CD “Virtual School of Cyril and Methodius” Chemistry lessons. 10-11 grades.