Chemistry lessons 8. Academy of entertaining sciences

The lesson was developed for UMK G.E. Rudzitis, F.G. Feldman.

primary goal this lesson- this is to generalize and consolidate the knowledge of students about the initial chemical concepts; activation of cognitive activity and increasing the motivation of students to study chemistry. Development of students' interest in chemistry and activation of their cognitive activity, using non-standard game forms learning activities. The lesson is held in the form of a tournament.

The lesson uses ICT, the need to use a computer presentation is dictated by the following reasons:

• Organization different types activities of students.
• Means for providing visibility and compaction of the material.
• Organization of self-examination without spending lesson time.
• Helps save class time

Methods: verbal, visual, use of ICT, problem-search.

Game Goals:

• repetition of the studied chemistry material to fill in the gaps and to prepare for the planned control work;
• development and strengthening of interest in chemistry, broadening the horizons of students, raising the level of their culture;
• development of communication skills, confidence and looseness in communication;
• fostering a responsible attitude to collective activity.

Target audience: for grade 8

Methodical development lesson on the topic "Acid" includes a presentation and summary of the lesson. Lesson learning new material on the topic, introduces students to the class inorganic compounds- acids, their general formula, classification, distribution in nature. Also, students will have the opportunity to get acquainted with the main inorganic acids.

Target audience: for grade 8

Methodological development includes a summary of the first chemistry lesson in grade 8 + presentation.
The objectives of the lesson are:
- to form an idea about the subject of chemistry, to introduce safety precautions when working in a chemical laboratory;
- to give the initial concepts of matter as an object of study of chemistry;
- learn to identify and describe the properties of substances.
The lesson is introductory to all recommended teaching materials.
The presentation presents illustrated theoretical material and control and measuring material for generalization and primary consolidation of the topic.

Target audience: for grade 8

This development of the lesson corresponds to the program material. Textbook used: O.S. Gabrielyan "Chemistry Grade 8". Methods and techniques are chosen in accordance with the age and individual characteristics of students, a student-centered approach to learning is used. In the lesson, various forms of work are used: frontal work, work in pairs, individual work. creative tasks, problem situation contribute to the development of cognitive abilities of students, the education of socially significant personality traits. During the lesson, students evaluate themselves on their own, using self-assessment sheets with developed assessment criteria. The material of the lesson traces interdisciplinary connections, connection with life. Children learn to analyze and summarize the material, draw their own conclusions, look for additional information in various sources (books, computer and media aids). A multimedia presentation was used to increase interest in learning.

Target audience: for grade 8

General lesson on the topic "Compounds of chemical elements" in chemistry Grade 8. The lesson is conducted in the form of a game-journey. This form contributes to the qualitative fixing of the material. The purpose of the lesson: to identify and consolidate students' knowledge on the topics covered with the help of assignments and standard standard tasks.

Target audience: for grade 8

The development is intended for students of the eighth grades on the topic "Oxidation-reduction reactions" (textbook by O.S. Gabrielyan. Chemistry. Grade 8). With the help of presentations, it is easier for students to learn the method of electronic balance, to comprehend the complex processes of oxidation and reduction.

Target audience: for grade 8

The lesson was prepared for participation in the competition "Teacher of the Year". The lesson is designed for students in grade 8 and those studying according to the Rudzitis textbook. Purpose: study physical properties, methods of obtaining, distribution of hydrogen. Lesson form: Lesson-explanation of new material. Equipment: computer, projector, presentation.

Chemistry lesson in 8th grade

(introductory lesson)

Meet Chemistry!

"Chemistry has an irresistible appeal

thanks to the vast, limitless power that

she bestows upon those who know her.”

Tasks:

To acquaint students with the history of the development of chemistry, to give the first ideas about this science;

Update students' knowledge of substances, begin to form ideas about the properties of substances and their transformations;

Develop students' analytical skills.

Thematic wall newspapers, cards with formulas of substances and chemical reactions, chemical beakers, flat-bottomed flasks, a dark glass jar, matches, dry fuel, a demonstration table, crucible tongs, a handkerchief, a porcelain crucible, collections of metals and plastics.Substances: Freshly prepared solutions of potassium iodide and lead acetate, phenolphthalein, soda ash, sodium hydrogen sulfate, ethanol, norsulfazole tablets, ammonium dichromate.

I . opening speech teachers.

There is science in the world, without which today it is impossible to realize the most fantastic projects and fabulous dreams. it- CHEMISTRY. In her piggy bank there are a lot of such miracles, before which the fantasies of the best storytellers of the world turn pale: as if Cinderella into a princess, she turns graphite into a brilliant diamond, gives paper the strength of metal, and metal gives memory. It is not for nothing that she is called a sorceress and a miracle worker: she feeds, waters, clothes, heals, washes, extracts minerals, allows her to rise into space and sink to the bottom of the ocean.

Each of you, without knowing it, carries out chemical reactions every day, without even leaving your home: lights matches and gas, cooks food. And the human body itself is a large chemical factory in which many chemical reactions take place.

Today is your first acquaintance with this amazing science. And the presentation will be held by students of the 9th grade. They will tell you about the history of the development of the science of chemistry, show you a lot interesting experiences, and at the end of the lesson, by answering the quiz questions, you will be able to purchase entrance tickets to the express train, which will rush you across the wide expanses of the planetChemistry - 8.

In the 8th grade, you begin to study a new subject for you.chemistry -the science of substances and their transformations.All substances surrounding us consist of chemical elements, of which there are now more than 110. When combined, atoms of different elements form more than twenty million substances.

To know the properties of substances is necessary to find their application. So, our distant ancestors appreciated the extraordinary hardness of silicon and used it to make weapons and tools. Some substances you already know: iron, aluminum, water, chalk, sugar, oxygen, carbon dioxide, plastics and others (demonstration of collections of metals, plastics). Not only substances on Earth, but the entire Universe consists of the same elements that scientists have discovered one after another on our planet.

In chemistry lessons, you will learn a lot of interesting things about chemical elements. And today we want to briefly introduce you to the history of the development of chemistry.

As a rule, most historians of chemistry distinguish the following main stages of its development:

1. Pre-alchemical period: until the III century. AD

In the pre-alchemical period, the theoretical and practical aspects of knowledge about matter developed relatively independently of each other. The origin of the properties of a substance was considered by ancient natural philosophy, practical operations with a substance were the prerogative of handicraft chemistry.

2. Alchemical period: III - XVII centuries.

The alchemical period, in turn, is divided into three sub-periods -Alexandrian(Greek-Egyptian) Arabic and European alchemy. The alchemical period is the time of the search for the philosopher's stone, which was considered necessary for the implementation of the transmutation of metals. In this period, the birth of experimental chemistry and the accumulation of a stock of knowledge about matter took place; alchemical theory based on ancient philosophical ideas about the elements, was closely associated with astrology and mysticism. Along with the chemical-technical "gold-making", the alchemical period is also notable for the creation unique system mystical philosophy.

3. The period of formation (association): XVII - XVIII centuries.

During the formation of chemistry as a science, its complete rationalization took place. Chemistry freed itself from the natural-philosophical and alchemical views of the elements as carriers of certain qualities. Along with the expansion of practical knowledge about matter, a unified view of chemical processes began to be developed and the experimental method began to be fully used. The chemical revolution that completed this period finally gave chemistry the appearance of an independent (albeit closely related to other branches of natural science) science, engaged in the experimental study of the composition of bodies.

4. The period of quantitative laws (atomic-molecular theory): 1789 - 1860.

The period of quantitative laws, marked by the discovery of the main quantitative laws of chemistry - stoichiometric laws, and the formation of the atomic-molecular theory, finally completed the transformation of chemistry into an exact science based not only on observation, but also on measurement.

5. Period of classical chemistry: 1860 - late XIX in.

The period of classical chemistry is characterized by the rapid development of science: periodic system elements, valency theory and chemical structure molecules, stereochemistry, chemical thermodynamics and chemical kinetics; Applied inorganic chemistry and organic synthesis achieved brilliant successes. In connection with the growth in the volume of knowledge about matter and its properties, the differentiation of chemistry began - the allocation of its separate branches, acquiring the features of independent sciences.

6. Modern period: from the beginning of the 20th century to the present.

At the beginning of the 20th century, there was a revolution in physics: the system of knowledge about matter based on Newtonian mechanics was replaced by quantum theory and the theory of relativity. Establishing the divisibility of the atom and creating quantum mechanics invested new content in the basic concepts of chemistry. The advances in physics at the beginning of the 20th century made it possible to understand the reasons for the periodicity of the properties of elements and their compounds, to explain the nature of valence forces, and to create theories of the chemical bond between atoms. The emergence of fundamentally new physical methods of research has provided chemists with unprecedented opportunities to study the composition, structure and reactivity of matter. All this together determined, among other achievements, the brilliant successes of biological chemistry in the second half of the 20th century - the establishment of the structure of proteins and DNA, the knowledge of the mechanisms of functioning of the cells of a living organism.

Second presenter

Chemistry originated in Egypt. Name« chemistry » comes from the word hemi, or huma (black), which the ancient Egyptians called their country. Thus, the word "chemistry" means the Egyptian art, which dealt with various minerals and metals. Chemistry was considered a divine science, was in the hands of the priests and was hidden from the uninitiated. The Arabs added to the word "chemistry" characteristic of Arabic prefix "al". The term "alchemy" and "alchemist" appeared. Now alchemy is called the period of development of chemistry with 4th to 16th centuries AD

The research of alchemists was aimed at searching for the "philosopher's stone" supposedly capable of turning any metal into gold. Kings and kings kept alchemists in their palaces to get gold for them. See how the alchemists worked.

Alchemist

- I will show you the experience "Turning water into gold".

One beaker contains a freshly prepared solution of potassium iodide, the other contains a solution of lead acetate. Both solutions are poured into a beaker with a larger capacity. A bright yellow precipitate of lead iodide occurs (showing a card with a chemical reaction).

2 KI + Pb ( CH 3 COO )2 = PbI 2 + 2 KCH 3 COO

In subsequent lessons, we will learn what such records of equations of chemical reactions mean.

Third host

But the alchemists never succeeded in turning metals into gold. Alchemy has been banned in many countries. People who were engaged in alchemical research were accused of witchcraft and burned at the stake. But science cannot be banned. Scientists discarded the prefix "al" from the word "alchemy" and got a new name - chemistry. That's what it's called nowa science that studies the substances around us, as well as their properties and transformations.

Today, chemical products occupy a dominant position in our Everyday life. Chemical research is carried out in the laboratories of scientific research institutes, at plants, factories, etc. Each school has a chemistry room and a chemistry lab.

Now let's get acquainted with some substances and chemical transformations.

- I will show you the experience "Turning water into raspberry syrup".

For the experiment, four chemical beakers and a dark glass jar are used. The first beaker contains phenolphthalein, the second contains sodium carbonate, the fourth contains sodium hydrosulfate, and the jug contains water. The third glass contains nothing.

In a jug of dark glass is ordinary water, pour it into four glasses. Then pour the water from the glasses, except for the last one, back into the jug, leaving the last glass as a control. Pour the water from the jug back into the glasses. Look: the solution has become bright crimson, like syrup! Pour the "syrup" into a jug, dilute it with "water" from the last glass. The last time we pour the water from the jug into the glasses. Look, the "syrup" turned into water again.

It seems to be a miracle! No, just in one glass there was phenolphthalein, in the other - a solution with an alkaline environment. When they are mixed, a raspberry-colored solution is formed. Remember:phenolphthalein in alkaline solutions always crimson. In order for the color to disappear, I added a little acidic solution. The acid neutralized the alkali and the solution became colorless.

Name the chemicals used in this experiment.

Second laboratory assistant

- Many of you love fairy tales and fantasy. Now you will see how the Alien or simply the Serpent Gorynych is born from the cocoon.

(Music sounds, the Pharaoh Serpent experience is demonstrated)

Experience Description

Grind a tablet of dry fuel and put it in a slide on a stand. Place three norsulfazole tablets on top of the fuel. Ignite dry fuel. Use a metal rod to correct crawling "snakes". After the end of the experiment, put out the fire by closing the plastic lid.

First laboratory assistant

- Now I’ll take the handkerchief in my hands, first I’ll soak it with spring water and set it on fire with the flame of a match.

(The experience "Fireproof scarf" is demonstrated)

Experience Description

Rinse the handkerchief in water, then wring it out lightly and soak it well in alcohol. Grab the handkerchief by one of its ends with crucible tongs and, holding them in an outstretched hand, bring a long splinter to the fabric. The alcohol will immediately flare up - it seems that the handkerchief is on fire. But the burning stops, and the handkerchief remains unharmed, since the ignition temperature of a wet cloth is much higher than for alcohol.

C 2 H 5 Oh + 3 O 2 = 2 CO 2 + 3 H 2 O

Name the substance that supports the processes of combustion and respiration. What do you know about the properties of this substance?

Second laboratory assistant

- At the end of our meeting, I will show an experiment called "Volcano". Of course, you know what a grandiose sight it is - a volcanic eruption. In ancient times, the volcano Vesuvius covered the city of Pompeii.

(Music sounds, experience is demonstrated.)

Experience Description

Insert a crucible or porcelain cup into the neck of the conical flask. The flask can be covered with plasticine, giving it the shape of a mountain, or a model of a hill can be made. Place a large sheet of paper under the flask or mockup to collect chromium oxide ( III ). Pour ammonium dichromate into the crucible, moisten it with alcohol in the center of the mound. The volcano is ignited with a burning splinter. The reaction is exothermic, proceeds rapidly, together with nitrogen, hot particles of chromium oxide fly out ( III ). If you turn off the light, you get the impression of an erupting volcano, from the crater of which incandescent masses pour out (showing a card with a chemical reaction).

( NH 4)2 Cr 2 O 7 = N 2 + Cr 2 O 3 + 4 H 2 O

(Chromium(III) oxide ) collect and save for other experiments).

Teacher

That's how many interesting chemical transformations you had to observe today in the lesson.

A chemical reaction can be judged by its signs - a change in the color of substances, the appearance of a smell, precipitation, the release of light and heat, the formation of a gaseous substance.

- What signs of chemical reactions can you name in the experiments demonstrated?

- Well, guys, did chemistry conquer you with its miracles? And now you also try to answer the quiz questions, which will be like entrance tickets for you to the wonderful world of substances and transformations.

The most common substance on earth. (Water)

It does not sink in water, does not burn in fire, exists only at temperatures below zero degrees.(Ice)

Name a metal that is liquid at room temperature. (Mercury)

Without this gas in the world

Animals and people would not live.

Children can name it

After all, he is called ....Oxygen

5) I live known in the world, In the thirteenth apartment. I am soft, light, malleable, Sparkling in the package. (Aluminum )

6) This gas is formed during lightning discharges. There is it in a pine forest, where it is easy to breathe.

And it does not leave a taste in the water at all, For that it disinfects it well. (Ozone )

Well done, all questions answered correctly.

What chemicals can you name now?

Did my assistants prove to you that chemistry is an interesting science? What helped you make sure of this? What experiments can you repeat at home to surprise your loved ones? But don't forget about safety.

But chemistry is one of the complex sciences included in the section of natural science. Millions of substances, and, therefore, millions of chemical formulas, chemical reactions, many laws and regularities. And you have to study these laws, the laws of chemistry, the laws of the universe. Anyone who devotes himself to this science can contribute to unraveling the mysteries of nature, creating new substances and materials that do not exist in nature.

During the school year, from lesson to lesson, we will gradually conquer the planet - Chemistry 8, which we can only master with the help of our knowledge.

I wish you success on this difficult but interesting path! Good luck!

According to the textbook: Preface. Introduction. Chapter 1.§one The subject of chemistry. Substances. The transformation of substances.

Prepare reports (optional) on the history of chemistry: “Chemical knowledge of ancient peoples”, “Alchemy”, “Practical chemistry in ancient Russia”.

Lesson topic:"Acids, their composition, classification and significance".

Lesson objectives:

Educational:

Consider the composition and classification of acids;

Continue the formation of skills to write down the formulas of substances of the main classes of inorganic compounds;

Continue the formation of skills to determine the degree of oxidation of chemical elements in compounds;

Developing:

Continue the development of students' thinking skills: compare, analyze, draw conclusions;

Continue developing skills in experimental work;

Continue the development of general educational skills and abilities;

Develop interest in the subject.

Educational:

To foster a culture of intellectual work and cooperation;

Cultivate a sense of responsibility, accuracy;

Contribute to the creation of a favorable psycho-emotional climate in the classroom.

Lesson type: combined

Teaching methods: verbal (story, explanation, conversation);

Illustrative;

Demo;

Partial search, problematic, research.

Equipment and reagents: laptop, projector, interactive board, presentation, samples of acids: hydrochloric, sulfuric, ascorbic, acetic, citric, test tubes, test tube racks, indicators, notebooks, worksheets, tables with acid formulas.

During the classes:

Org. moment

Knowledge update.

? Guys, we have begun to study the classes of inorganic compounds. What classes of substances have we already met?(Oxides, hydrides and volatile hydrogen compounds, bases).

CaO, SO 2 , Fe 2 O 3 , Na 2 Oh, Cl 2 O 7 (Slide 1).

? What formulas do you see?

? What substances are called oxides?

? To which class do the following substances belong? KOH, Al(OH) 3 , Va(OH) 2 , Cu(OH) 2 ?

? What substances are considered bases?

? What determines the number of hydroxyl groups in a base?(On the degree of oxidation of the metal.)

(Slide 2). Tic-tac-toe "Foundations"

Find a winning path consisting of base formulas.

Playing field No. 1 Playing field No. 2

? What do the bases in the first playing field have in common and how do they differ from the bases located on the playing field number 2?(In the first playing field - soluble bases, in the second - insoluble.)

Give examples

? What are the characteristics of soluble bases? What precautions should be taken when handling alkalis?

Task for the classification of compounds.(Slide 3)

Divide the substances below into three groups. Name these groups

CaO, Al(OH) 3 , CuO, HCl, H 2 Oh, Cl 2 O 7 , Fe(OH) 2 , HNO 3 , NaOH, H 2 SO 4 .

Learning new material

In the third group, you placed substances that are still unfamiliar to you, which belong to the class of acids. It is with the substances of this class that we will get acquainted today. So, the topic of our lesson is "Acids: composition, classification and significance."Write the topic of the lesson in workbook. (Slide 4).

? What do we need to know about acids?(Composition, formulas, names, classifications, meaning, safety regulations).

Variety of acids (Slide 5).

Acid study plan (Slide 6).

Compound.

Classification.

Nomenclature and related oxides

Significance and application.

Safety rules for working with acids.

Composition of acids (Slide 7).

You see the formulas of three acids: hydrochloricHcl , sulfuricH 2 SO 4 and phosphoric acidH 3 RO 4 . What do they have in common?

Yes, this is the presence of hydrogen atoms in their composition, with which all three formulas begin. The rest is called the acid residue.

acids – complex substances, the molecules of which consist of hydrogen atoms and an acid residue.

Acid classification

A) the presence of oxygen . (Slide 8)

? Notice the differences in the acid residues of the two groups of acids on the board. What is this difference?

That's right, the acid residues of sulfuric, nitric, phosphoric and perchloric acids contain oxygen, and the acid residues of hydrochloric, hydrobromic, hydrosulfide and hydrofluoric acids do not contain oxygen.

The presence of oxygen or its absence is one of the signs of the classification of acids. On this basis, acids are divided into two groups:anoxic andoxygen-containing. Give examples of oxygen-free and oxygen-containing acids from the table.

B) Classification of acids by basicity . (Slide 9).

? Look at the acid formulas on the board. They are divided into three groups on a certain basis. What do you think this sign is?

Basicity - the number of hydrogen atoms in the acid.

Give examples of monobasic, dibasic and tribasic acids from the table.

By the number of hydrogen atoms, you can determine the total charge of the acid residue, which, when dissolved in water, forms a negatively charged ion.

Hydrogen, when dissolved, forms a positively charged ion, the charge of which is +1. The designation of the charge of an ion has its own peculiarities.

C) Classification of acids by solubility in water (Slide 10).

By the way, the ability to dissolve in water is another sign of the classification of acids. On this basis, all acids are divided into two groups: soluble and insoluble. Let's give examples using the solubility table.

The oxidation state of elements in acids and the oxides corresponding to acids. (Slide 11).

1 −1 +1 − 2 +1 X − 2 +5 − 2

HCl H 2 S N 3 RO 4 → P 2 O 5 - phosphoric acid

(+1) 3 +x + (−2) 4 = 0

x − 5 = 0

X = + 5

1 + 3 − 2 +3 − 2

H 3 RO 3 → P 2 O 3 - phosphorous acid

Determine the oxides corresponding to acids.(Slide 12).

H 2 SO 4 → SO 3 HNO 3 → N 2 O 5

H 2 SO 3 → SO 2 HNO 2 → N 2 O 3

Nomenclature of acids

Anoxic acids:

A vowel is added to the name of the acid-forming element"about"

and the words "hydrogen acid"

HCl– hydrochloric acidH 2 S - hydrosulphuric acid

Oxygen-containing acids:

The suffix is ​​added to the Russian name of the acid-forming element:

If the element showshigher SO(equal to group number)

+6

– "-n" and ending "-th":H 2 SO 4

sulphuric acid

If the CO of the element below higher +4

– "-ist" and ending "-aya":H 2 SO 3

sulfurous acid

The value of acids in nature and human life (Slide 13-14).

Acids in nature

Acids in human life

In the human body

In culinary food

In medicine

AT national economy

acid rain

Acid Safety Rules (Slide 15-16).

In the 19th century, the scientist Justus Liebig lived and worked in Germany. He was an experimenter from God, with early years enthusiastically helped his father to prepare varnishes, paints and medicines. Once upon a lesson Greek Liebig's satchel exploded with explosive mercury. The father, making sure that the boy was not made for the gymnasium, gave him as an apprentice to a pharmacist. A few months later, the thirteen-year-old chemist knew better than a teacher how to formulate medicines. After another explosion, he was expelled, but he did not leave chemistry classes and at the age of 23 he became a professor at the University of Giessen. Here is how Karl Vogt, a chemist who worked with Liebig, describes one case. “Liebig enters, in his hands a bottle with a ground stopper. “Come on, bare your hand,” he says to Vogt and touches his arm with a wet cork. “Isn’t it true, does it burn? Liebig asks calmly. “I just mined anhydrous formic acid.” Do you think Liebig handled acids correctly?

(No. When working with chemicals you need to be careful: remove your hair, roll up the sleeves of your clothes, pour no more than 1-2 ml of solutions, holding the jar with the label up.)

? How can acid be determined without resorting to extreme methods?

Consolidation of knowledge

Laboratory experience

INSTRUCTION MAP:
Form of work: steam room.
Working time - 8-10 minutes.
Exercise:
Examine the color of indicators in acid environments.
Equipment and reagents:
3 test tubes with hydrochloric and 3 test tubes with citric acid, liquid indicators: litmus, phenolphthalein and methyl orange, glass rods.
Safety regulations:
Attention! It is necessary to work with acids carefully, as you can get burned or poisoned. If acid gets on the skin, wash it off with a stream of water.
Conducting the experiment and reporting the results:

1 group: Add a drop of phenolphthalein to a test tube with hydrochloric acid. Stir with a glass rod. Record the results of observations in the table.
Add a drop of methyl orange to the 2nd test tube with hydrochloric acid. Stir with a glass rod. Record the results of observations in the table.

Add a drop of litmus to the third test tube with hydrochloric acid. Stir with a glass rod. Record the results of observations in the table.

2 group: Add a drop of phenolphthalein to a test tube with citric acid. Stir with a glass rod. Record the results of observations in the table.
Add a drop of methyl orange to the 2nd tube with citric acid. Stir with a glass rod. Record the results of observations in the table.

Add a drop of litmus to the 3rd test tube with citric acid. Stir with a glass rod. Record the results of observations in the table.

Action of acids on indicators

Which indicators change color in acids?(Litmus and methyl orange).
? Did you observe the same color changes of these indicators in both acids?(Yes).
? What color did litmus and methyl orange acquire in both hydrochloric and citric acids?
(Litmus turned red and methyl orange turned pink).
Based on the experiments carried out, we draw the following conclusions:
regardless of the type of acid (organic or inorganic), the indicators change their color in the same way; which means that all acids have similar properties.
? What is it connected with?(With the presence of hydrogen atoms).

If there is time. Task on slide 18

Summarizing. Reflection.

Summing up the lesson. Grading.

Continue the phrase

Today in class I learned...

I learned…

It was not clear to me...

For me this lesson...

It aroused interest...

Difficulties arose when...

Homework. §20, p. 102-107, learn the formulas and names of acids, task 6 (“Worksheet”), task 1, p.107 (textbook).

This fascinating chemistry

First chemistry lesson grade 8

Lesson objectives.Educational: introduce students to the subject of chemistry; to give an idea of ​​chemistry as an exact science, not devoid of lyrics; present points of view on the origin of the word “chemistry”; show the relationship of chemistry with other sciences.

Developing: development of cognitive interest in the subject; familiarization of students with achievements modern science, with biographies of great chemists.

Educational: fostering love for one's Fatherland, pride in the achievements and successes of our country in the field of science; fostering a caring attitude towards one's health; fostering respect for the different points of view of other people.

Equipment and reagents. Computer, video clips from the collection of OMC modules, cards with quiz questions and descriptions of substances, portraits of J.Y. Berzelius, D.I. Mendeleev, R. Bunsen, F.A. Kekule, N.N. Beketov, S. Arrhenius .Vuda, N.N. Zinina; racks with test tubes, chemical cups, crucible tongs, spirit lamp, porcelain cup, conical flask, splinter; water, solution ammonia, acetic acid solution, ethyl alcohol, gasoline, salt, sugar, starch, flour, pieces of ice, cotton wool, river sand, sawdust, paraffin, blue vitriol, iron filings, copper shavings, red phosphorus, sulfur, KI solutions, Pb (NO 3) 2 , KOH, CuSO 4 , NaOH, FeCl 3 , Na 2 SO 4 , BaCl 2 , HCl, Na 2 CO 3 , CaCl 2 , litmus, phenolphthalein, ammonium dichromate.

DURING THE CLASSES

1. Organizational moment.

Introduction to the class.

2. Actualization of knowledge.

Teacher.What associations does the word “chemistry” evoke in you?

What group of sciences does chemistry belong to?

Do you already know how the words are translated: “geography”, “geometry”, “biology”, but how is the word “chemistry” translated?

Student responses.

3. Information.

Teacher.There are several points of view on the origin of the word "chemistry".

Video clips from the collection of CMI modules are shown (RNMC is a software product of the Ministry of Education, http://www.shkola.edu.ru).

Teacher. We will look at the fragment “History of the development of chemistry”(mmlab.chemistry.002i.oms), in which versions of the translation of the word “chemistry” are given.

a) hmi(Egyptian) - "black" land. The ancient name of Egypt, where the science of chemistry originated.

b) Keme(Egyptian) - "black" science. Alchemy as a dark, diabolical science (compare with the sorcery - witchcraft based on the action of evil spirits).

in) Huma(ancient Greek) - "casting" of metals; same root and Greek humos- "juice".

G) Kim(Old Chinese) – “gold”. Then chemistry can be interpreted as “gold making”.

4. Warm up.

Teacher. Although chemistry is a complex science, you already know a lot from other sciences, from life experience. We will see for ourselves: you are offered cards with questions from various topics of the 8th, 9th, 10th grade chemistry course. Who wants to answer?

Questions of the quiz “Is Chemistry So Difficult?”

Why do we blow on a match when we want to put it out?

(Exhaled air contains CO 2 .)

Why can't gasoline fires be extinguished with water?

(Gasoline is lighter than water and does not mix with it.)

How to carry 1 liter of water in the palm of your hand without spilling a drop?

(Freeze in ice.)

Which is warmer: three shirts or a triple-thick shirt?

(Three shirts.)

In which sea can you not drown? Why?

(In the Dead Sea, it is very salty.)

Which is heavier: 1 kg of iron or 1 kg of cotton?

(They are equal.)

From 1 g of what metal can a wire 2.5 km long be drawn?

(From gold.)

Is it possible to fill only half of the balloon with air?

(It is forbidden.)

What does the expression "water off a duck's back" mean?

(Feathers waterfowl do not wet with water.)

What metal compounds give the planet Mars a red tint?

(Compounds of iron.)

Three identical burning candles were simultaneously covered with three jars with a capacity of 0.4 l, 0.6 l and 1 l. What will happen?

(The candle will go out the earlier, the smaller the volume of the jar.)

After each answer, the teacher says which topic and class the question belongs to.

For a correct answer, the student receives a solubility table or a small periodic table as a keepsake.

Not all questions can be used, depending on the time of answers to them, but it is necessary to tell the children that their new knowledge will be based on what they already have, obtained in other lessons, and the teacher will help to deal with difficult questions.

5. Game “Guess the substance”.

Teacher. What is chemistry without experiments? Of course, you yourself want to "chem"! Do you know substances? Can you tell them apart? Let's check…

There are three trays of substances on the teacher's display table - one contains only colorless transparent liquids, another contains only white solids, and the third contains multi-colored solids.

V e s e s t v a

1st tray. In small cups: water, ammonia solution, acetic acid solution, ethyl alcohol, gasoline.

2nd tray. Solids in small cups white color: salt, sugar, starch, flour, ice cubes, cotton wool.

3rd tray. In small cups there are solid multi-colored substances: river sand, sawdust, paraffin, blue vitriol, iron filings, copper shavings, red phosphorus, sulfur.

Teacher. We need three volunteers as experimenters who will try to determine the proposed substances, necessarily explaining their actions.

The teacher warns students about the observance of safety rules when performing the experiment.

Students try to identify substances.

A video fragment is shown - the module "Alchemical laboratory" (mmlab.chemistry.003i.oms), which gives an idea of ​​the life and work of alchemists.

6. Information. Interesting Facts from the life of chemists.

Dramatizations prepared in advance by students - members of the NOU are played out.

Portraits of scientists are shown.

Berzelius' cook.

Residents of a small town in which the famous Swedish scientist J.J. Berzelius lived and worked once asked his cook: “What, in fact, does your master do?”

“I can’t say exactly,” she answered, “He takes a large flask with some kind of liquid, pours it into a small one, shakes it, pours it into an even smaller one, shakes it again and pours it into a very small one ...”

"And then?"

“And then he pours everything out!”

The story is accompanied by a demonstration of experience by the teacher. For the experiment, 4 flasks of different sizes are taken. A colorless alkali solution is first poured into a large flask, a smaller flask is pre-moistened with a solution of phenolphthalein. The alkali solution is poured into a flask with phenolphthalein, the solution turns crimson. In a third flask, even smaller, a little hydrochloric acid solution of a higher concentration than the alkali solution is poured, and then the colored alkali solution is poured into it. In the third flask, the solution becomes colorless. And when the whole mixture is poured into a very small flask, in which there is a little concentrated alkali solution, the solution again acquires a crimson color.

Suitcase master.

D.I.Mendeleev loved to bind books, glue frames for portraits, and make suitcases. He usually made purchases for these works in Gostiny Dvor. One day, while choosing the right product, he heard behind him: “Who is this venerable gentleman?” “You need to know such people,” the clerk replied with respect in his voice. “This is the suitcase master Mendeleev!”

Good friend.

One day a colleague came to Robert Bunsen. They talked for an hour and a half. And the guest was about to leave, when suddenly Bunsen said: “You cannot imagine how weak my memory is. After all, when I saw you, I thought that you were Kekule!” The visitor looked at him in amazement and exclaimed: “But I am Kekule!”

Thieves in the library.

Once, an excited servant ran into the office of Academician N.N. Beketov: “Nikolai Nikolayevich! There are thieves in your library!” The scientist, not immediately looking up from his calculations, calmly asked: “And what are they reading there?”

At work.

R. Wood (1868–1955)

American physicist Robert Wood began his career as a laboratory assistant. One day, his boss went into a room filled with the roar and clang of pumps and equipment, and found Wood there, engrossed in reading a criminal novel. The chief's indignation knew no bounds.

- Mister Wood! he exclaimed, inflamed with anger, “you ... you allow yourself to read a detective story ?!

- For God's sake, I'm sorry! Wood was confused. - But with such noise, poetry is simply not perceived!

Heroic amusements of Professor Zinin.

Was assault applied to students in Russia? There was no gross violence, but the teachers, although rarely, used cuffs. The well-known academician N.N. Zinin not only scolded negligent students, but also beat them. Nobody was offended by this, because. it was allowed to give change to the academician. But there were no hunters to take retaliatory measures. Zinin possessed great physical strength and could so squeeze the enemy in his arms that he could not recover for a long time.

N.N.Zinin (1812–1880)

7. Do-it-yourself miracles.

There are racks with two test tubes on the students' tables.

Teacher. You yourself are wonderful experimenters, with the help of simple tricks you can work wonders. Your task is to mix the contents of the test tubes with each other.

The teacher explains to the students the safety rules for the experiment.

Teacher.The solutions are selected in such a way that in each case either precipitates of different colors fall out, or gas is released, or the color changes.

The students perform the experiment, observe the changes taking place. (For example, solutions of potassium iodide and lead (II) nitrate; potassium hydroxide and copper (II) sulfate; sodium hydroxide and iron (III) chloride; sodium sulfate and barium chloride; litmus and hydrochloric acid, litmus and sodium hydroxide; acetic acid and sodium carbonate, etc.)

8. Let's play...

The game "What's in the black box?"

The class is divided into teams of 4 people.

Teacher.Assignment to commands: according to the description of the features of the properties, discovery history, familiar applications, you have to guess which substance is in question. If you guess the substance on the first try, you get 5 points, on the second - 4 points, and so on. Answers are given in writing so that the other teams can continue the game. If the team gave the wrong answer, it has the right to continue the game, but gets minus 1 point.

Based on the results of two or three rounds, the winning team is determined, which receives a prize.

The host gives the correct answer at the end of each round. Points are kept on the board (you can choose an assistant from the guys in the class).

F irst thing

1) This substance in the old days was called the ruler of life and death. He was sacrificed to the gods, and sometimes worshiped as a deity.

(5 points.)

2) It served as a measure of wealth, power, stamina, power, was considered the keeper of youth and beauty.

(4 points.)

3) According to beliefs, it has the ability to help a person in all his affairs, save from troubles and misfortunes.

(3 points.)

4) “He will be born from water, but he is afraid of water.”

(2 points.)

5) It is widely used in everyday life, in cooking, in leather business, in the textile industry and others.

(1 point)

(Answer. Salt.)

S e c o n e

1) The ancient Egyptians called it “vaaepere”, which means “born in the sky”.

(5 points.)

2) The ancient Copts called it “the stone of the sky”.

(4 points.)

3) Products from it were valued more than gold. Only very rich people could have rings and brooches made from it.

(3 points.)

4) Alchemists considered it to be such a base metal that it was not worth dealing with it.

(2 points.)

5) A century is named after him. It is a ductile soft metal.

(1 point)

(Answer. Iron.)

9. “Did you know that…”

Teacher. Now we will learn about the achievements of modern science, about interesting discoveries in the field of chemistry and related sciences.

The information is accompanied by a computer presentation, the slides of which are illustrated with photographs, video clips, flash animations, etc.

Nanotechnology: today and tomorrow. Nano (from the Greek. nanos- dwarf) - a billionth of something. A field of science that studies the properties of objects 10–9 m in size. Nanotechnology manipulates individual particles ranging in size from 1 to 100 nm, and also develops devices of similar sizes. Now powders and suspensions have been created that improve the operation of engines and mechanisms. Coatings made of materials made using nanotechnology prevent rust, help the material to self-clean or not be wetted by water. The first nanorobots are able to travel through the body of animals. Hydrogen can be safely stored using nanotubes. In the future, it is possible to design any molecules and create superstrong materials. In medicine, it is planned to create targeted drugs that penetrate into the affected tissue or tumor; the use of nanorobots for the diagnosis and treatment of almost all diseases, the cultivation of tissues and organs. In electronics, this is the creation of subminiature electronic devices, flexible displays, electronic paper, new types of engines and fuel cells (http://www.aif.ru).

Many glaciologists believe that the thickness of the polar ice sheets is shrinking at an unabated pace. For 5 years, the volume of ice descending into the Atlantic annually has increased by almost 2 times, which is equivalent to a rise in the level of the World Ocean by 0.5 mm per year. Antarctica between 2002 and 2005 lost annually an average of 152 km 3 of ice. The ocean level by 2100 may rise by 4–6 m from present-day levels.

Greek and Latin inscriptions made on the stones 2000 years ago are not readable due to the erosion that destroyed them. To restore the inscriptions, scientists used the fluorescence method: when X-rays bombard the surface, the atoms come into an excited state, and then, returning to a state of rest, emit visible light. This makes it possible to determine the traces of lead or iron left by the chisel of the ancient author.

Russian chemists figured out how to recycle plastic bottles, and also synthesized a new filler for rubbers and polymers. Hydrogen fuel will give clean water instead of exhaust gases.

In the USA, a transparent polymer wall covering has been developed to which nothing sticks. It's a type of Teflon. On such a coating it is impossible to write or draw with paints, chalk or felt-tip pen. The coating can be used to protect the bottoms of marine vessels from fouling and the fuselages of aircraft from icing.

10. Entertaining demonstration experiments.

Teacher.Today was your first acquaintance with chemistry. Of course, you are waiting for something unusual, wonderful. I will try to transform into a magician and show you the wonders of chemistry.

The teacher demonstrates experiences.

"Smoke without fire".

Two cups are moistened with concentrated solutions of ammonia and hydrochloric acid, and then they are brought to each other. Observe smoke without fire.

“From one glass - sparkling water, raspberry juice and milk.”

Colorless transparent solutions of hydrochloric acid, calcium chloride and phenolphthalein are poured into three identical beakers. Pour sodium carbonate solution into a porcelain mug. Then sodium carbonate is poured from the mug in turn into each of the three glasses. In the first of them, gas is rapidly released (“soda”), in the second, a white precipitate appears (“milk”), and in the third, the solution becomes raspberry due to a change in the color of the indicator in an alkaline solution (“raspberry juice”).

"Fireproof scarf".

A handkerchief is soaked in water and then in ethyl alcohol. With the help of crucible tongs, it is brought to a burning spirit lamp and set on fire. Despite the huge flame, the handkerchief remains intact in the end, because. alcohol ignites and burns out before a damp cloth ignites.

Volcano on the table.

A porcelain cup is placed on the neck of the conical flask. A large sheet of paper is placed under the flask. Ammonium dichromate is poured into a cup, slightly moistened with alcohol in the center. The “volcano” is lit with a burning splinter. The reaction proceeds violently, the impression of an erupting volcano is created, from the crater of which red-hot masses pour out.

11. Summing up the lesson.

Literature

Gabrielyan O.S. Chemistry. 8th grade. Moscow: Bustard, 1997; Aleksinsky V.N. Entertaining experiments in chemistry. M.: Education, 1995; Priroda, 2007, No. 3; Ibid., 2006, No. 5; Science and Life, 1994, No. 8; Kozhanova E.A. How do I conduct a lesson-game. Chemistry at school, 1995, No. 6, p. 21.

Internet resources

Key words: Chemistry 8th grade. All formulas and definitions, symbols physical quantities, units of measurement, prefixes for designating units of measurement, ratios between units, chemical formulas, basic definitions, briefly, tables, diagrams.

1. Symbols, names and units of measurement
some physical quantities used in chemistry

2. Relations between units of physical quantities

3. Chemical formulas in grade 8

4. Basic definitions in grade 8

• Atom- the smallest chemically indivisible particle of a substance.
• Chemical element a certain type of atom.
• Molecule- the smallest particle of a substance that retains its composition and Chemical properties and made up of atoms.
• Simple substances Substances whose molecules are made up of atoms of the same type.
• Complex Substances Substances whose molecules are made up of different types of atoms.
• The qualitative composition of the substance shows what atoms it consists of.
• The quantitative composition of the substance shows the number of atoms of each element in its composition.
• Chemical formula- conditional record of qualitative and quantitative composition substances through chemical symbols and indices.
• Atomic mass unit(a.m.u.) - a unit of measurement of the mass of an atom, equal to the mass 1/12 carbon atom 12 C.
• mole- the amount of a substance that contains the number of particles equal to the number of atoms in 0.012 kg of carbon 12 C.
• Avogadro constant (Na \u003d 6 * 10 23 mol -1) - the number of particles contained in one mole.
• Molar mass of a substance (M ) is the mass of a substance taken in an amount of 1 mol.
• Relative atomic mass element BUT r - the ratio of the mass of an atom of a given element m 0 to 1/12 of the mass of a carbon atom 12 C.
• Relative molecular weight substances M r - the ratio of the mass of the molecule given substance to 1/12 of the mass of a carbon atom 12 C. The relative molecular mass is equal to the sum of the relative atomic masses of the chemical elements that form the compound, taking into account the number of atoms of this element.
• Mass fraction chemical element ω(X) shows what part of the relative molecular weight substance X falls on this element.

ATOMIC-MOLECULAR STUDIES
1. There are substances with a molecular and non-molecular structure.
2. There are gaps between the molecules, the dimensions of which depend on state of aggregation substances and temperatures.
3. Molecules are in continuous motion.
4. Molecules are made up of atoms.
6. Atoms are characterized by a certain mass and size.
In physical phenomena, molecules are preserved, in chemical phenomena, as a rule, they are destroyed. Atoms at chemical phenomena rearrange to form new molecules.

THE LAW OF CONSTANT COMPOSITION OF A SUBSTANCE
Each chemically pure substance of molecular structure, regardless of the method of preparation, has a constant qualitative and quantitative composition.

VALENCE
Valency is the property of an atom of a chemical element to attach or replace a certain number of atoms of another element.

CHEMICAL REACTION
A chemical reaction is a process in which another substance is formed from one substance. Reagents are substances that enter into chemical reaction. Reaction products are substances that are formed as a result of a reaction.
Signs of chemical reactions:
1. Release of heat (light).
2. Color change.
3. The appearance of a smell.
4. Precipitation.
5. Gas release.