Chemistry lesson 8. Chemistry video lessons

A chemistry workbook for 8th grade Gabrielyan is a set of ready-made homework assignments, including solved problems, calculated reaction equations, taken from O.S. Gabrielyan’s textbook, which is the classic basis for studying chemistry in 8th grade in Russian secondary schools.

Chemistry book for grade 8 Gabrielyan O.S. 2013-2019

Problems and reaction equations in a chemistry course are difficult practical tasks that not all schoolchildren can complete the first time. Eighth-graders may experience particular difficulties when preparing homework: in the 8th grade, students are assigned a fairly large amount of homework, which does not allow them to waste a lot of time preparing each subject.

Our website offers schoolchildren GDZ in chemistry for the 8th grade Gabrielyan, which allows students to:

1. do your homework well;
2. understand the mechanisms of problem solving;
3. consolidate theoretical material studied in class;
4. prepare for tests and exams in the subject.

Based on ready-made answers and solutions, parents can check their children's progress in chemistry and help them with their homework.

Our resource has a set of significant advantages:

• the required textbook can be easily found through the search bar;
• by clicking on the problem number in the table, you can immediately go to the online answer;
• the site is available not only on computers - it has an up-to-date version for tablets and phones.

We monitor the database of solvers for updates and strive to ensure that there are several online answers for one task.

Answers from the GDZ textbook on chemistry for grade 8 Gabrielyan

Currently, the curriculum for secondary schools in Russia is compiled on the basis of the textbook by Gabielyan O.S., published by the Drofa publishing house in 2013.

The textbook consists of an introductory part (6 paragraphs) and 5 main chapters that cover such important topics as:

1. Atomic structure and atomic compounds of chemical elements;
2. Simple substances, their properties;
3. Mixtures of substances and solutions;
4. Ion exchange reactions;
5. Redox processes.

The textbook includes two chemical workshops (laboratory work). All sections of the textbook are supported by practical questions, tasks, and exercises that allow you to effectively master the theory of the subject.

The lesson was developed for the educational complex G.E. Rudzitisa, F.G. Feldman.

The main goal of this lesson is to generalize and consolidate students’ knowledge of basic chemical concepts; activating cognitive activity and increasing students' motivation to study chemistry. Development of students' interest in chemistry and activation of their cognitive activity, using non-standard game forms of educational activities. The lesson is conducted in the form of a tournament.

ICT is used in the lesson; the need to use a computer presentation is dictated by the following reasons:

• Organization of various types of student activities.
• A means to provide visibility and compaction of material.
• Organization of self-test without wasting lesson time.
• Allows you to use lesson time economically

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

Goals of the game:

• repetition of the studied chemistry material to eliminate gaps and to prepare for the scheduled test;
• development and strengthening of interest in chemistry, broadening the horizons of students, increasing the level of their culture;
• development of communication skills, confidence and ease in communication;
• fostering a responsible attitude towards collective activities.

Target audience: for 8th grade

Methodological development of a lesson on the topic "Acids" includes a presentation and lesson notes. A lesson in studying new material on the topic introduces students to the class of inorganic compounds - acids, their general formula, classification, distribution in nature. Students will also have the opportunity to become familiar with basic inorganic acids.

Target audience: for 8th grade

Methodological development includes notes from the first chemistry lesson in 8th grade + presentation.
The objectives of the lesson are:
- form an idea of ​​the subject of chemistry, introduce safety precautions when working in a chemistry laboratory;
- give initial concepts about matter as an object of study of chemistry;
- teach 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 measurement material for generalization and initial consolidation of the topic.

Target audience: for 8th grade

This lesson development corresponds to the program material. Textbook used: O.S. Gabrielyan “Chemistry 8th grade”. Methods and techniques are selected in accordance with the age and individual characteristics of students, and a person-centered teaching approach is used. During the lesson, various forms of work are used: frontal work, work in pairs, individual work. Creative tasks and problem situations contribute to the development of students’ cognitive abilities and the development of socially significant personality traits. During the lesson, students evaluate themselves independently using self-assessment sheets with developed assessment criteria. The lesson material traces interdisciplinary connections and connections with life. Children learn to analyze and summarize material, draw their own conclusions, and 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 8th grade

General lesson on the topic "Compounds of chemical elements" in chemistry, grade 8. The lesson is conducted in the form of a travel game. This shape contributes to high-quality fixation 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 typical tasks.

Target audience: for 8th grade

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

Target audience: for 8th grade

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

Images of textbook covers are shown on the pages of this site solely as illustrative material (Article 1274, paragraph 1, part four of the Civil Code of the Russian Federation)

• Chemistry 8th grade. Problem book Kuznetsova, Levkin Ventana-Count
• Collection of problems and exercises in chemistry, grade 8 Khomchenko New wave
• Chemistry 8th grade. Federal State Educational Standard Rudzitis, Feldman Education
• Tests and tests in chemistry, grade 8. Federal State Educational Standard Gabrielyan, Krasnova Bustard
• Troegubova Vako
• Testing and measuring materials (CMM) in chemistry, grade 8. Federal State Educational Standard Koroshchenko Exam

Workbooks

• Chemistry workbook grade 8 Eremin, Drozdov Bustard
• Gabrielyan, Sladkov Bustard
• Notebook for assessing the quality of knowledge in chemistry, grade 8. Federal State Educational Standard Gabrielyan, Kuptsova Bustard
• Workbook on chemistry 8th grade. Federal State Educational Standard Gabruseva Enlightenment
• Exercise book for chemistry 8th grade. Federal State Educational Standard Gara Enlightenment
• Exam notebook for chemistry 8th grade. Federal State Educational Standard Bobyleva, Biryulina Education
• Workbook on chemistry 8th grade. Federal State Educational Standard Borovskikh. To the Rudzitis textbook Exam
• Workbook on chemistry 8th grade. Federal State Educational Standard Mikityuk. To Gabrielyan's textbook Exam

Tests

Chemistry workbooks for 8th grade

• Many parents are increasingly tormented by the question of how to help their children with homework in subjects such as chemistry and physics, since these sciences are complex and simply overwhelming for many students. To solve problems with homework, there are GDZ in chemistry for 8th grade. This is a real magic wand not only for students of any category, but also for parents who are concerned about their children’s learning.
• Only those students who know well the specifics of this subject and the peculiarities of solving problems in a certain class can cope with homework problems in chemistry. Therefore, the help of a solver in such cases is a brilliant solution for parents. Thanks to the chemistry workbook, an 8th grade student will be able not only to copy ready-made assignments from it (since this does not lead to a serious understanding of the subject), but also to understand how to solve many intricate problems, remember the material that was studied in class, and, if necessary, refer to the textbook . The sequence of solutions to problems in the solution book is described in detail and clearly, even those who have forgotten a lot of the material studied can understand them. Therefore, the established opinion that such books are used only by those who do not want to study is erroneous; many students turn to solution books who consider it their duty to understand the material being studied.

Chemistry 8th grade - competent study of science from the basics

• In the eighth grade, high school students begin to learn a new discipline - the science of chemistry. Considering the high practical, applied significance that it has, the demand for knowledge for further choice of profession, it is important from the very beginning to carefully and thoughtfully work with theoretical and practical material on the subject. Not everything always works out well; many topics are quite complex. In this case, you should not immediately write down chemistry as one of the disciplines with which it “didn’t work out.” Competent approaches and complexes for its study, selection of high-quality literature and workbooks for it will allow you to overcome temporary difficulties and deal with the most complex issues.
• But for this you need to work with GDZ not from time to time, but systematically. Not only in order to complete the task assigned at school, but also to analyze the problem in depth, at all levels, including those of increased complexity, to prepare for and participate in subject chemical Olympiads, school and held at other venues. For this to become a reality, you need:
  - develop a competent plan, a program of independent work. You can do this yourself or by contacting a teacher or tutor;
  - draw up a schedule for completing sections and topics, solving problems, and conducting practical work;
  - from time to time, monitor the results achieved and adjust the work plan based on the data from such analysis.
• The main topics studied in 8th grade chemistry include:
  - what is chemistry, with the help of what methods and technologies is it studied;
  - what is a substance, chemical laws and formulas;
  - atoms;
  - simple substances and compounds;
  - transformations, operations with substances, solutions;
  - equations and reactions.
• In addition to the theoretical textbook on chemistry for grade 8, it is recommended to include workshops and test materials in the kit for high-quality study of the discipline. Among them:
  - workbook;
  - didactic materials;
  - notebook for practical work;
  - collections of practical and experimental problems;
  - notebooks for laboratory and experiments;
  - simulators and test work in the discipline.
• By devoting even a little time to studying the problems posed by the discipline, but observing the principle of regularity, eighth-graders will be able to achieve high results in chemistry.

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

Lesson objectives:

Educational:

Consider the composition and classification of acids;

Continue developing the ability to write down the formulas of substances of the main classes of inorganic compounds;

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

Educational:

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

Continue developing experimental work skills;

Continue the development of general educational skills;

Develop interest in the subject.

Educational:

Foster a culture of knowledge work and collaboration;

Foster a sense of responsibility and accuracy;

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

Lesson type: combined

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

Illustrative;

Demonstration;

Partially search, problem-based, research.

Equipment and reagents: laptop, projector, interactive whiteboard, 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

Updating knowledge.

? Guys, we have started studying classes of inorganic compounds. What classes of substances have we already become familiar with?(Oxides, hydrides and volatile hydrogen compounds, bases).

CaO, SO 2 , Fe 2 ABOUT 3 , Na 2 Oh, Cl 2 ABOUT 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 , Ba(OH) 2 , Cu(OH) 2 ?

? What substances are considered bases?

? What determines the number of hydroxyl groups in the base?(Depending on the oxidation state of the metal.)

(Slide 2). Tic Tac Toe "Foundations"

Find the winning path consisting of the base formulas.

Playing field No. 1 Playing field No. 2

Name these reasons.

? What do the foundations in the first playing field have in common and how do they differ from the foundations located on the playing field No. 2?(In the first playing field - soluble bases, in the second - insoluble.)

Give examples

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

Compound classification task.(Slide 3)

Classify the substances below into three groups. Name these groups

CaO, Al(OH) 3 , CuO, HCl, H 2 Oh, Cl 2 ABOUT 7 , Fe(OH) 2 , НNO 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 substances of this class that we will get acquainted today. So, the topic of our lesson is “Acids: composition, classification and meaning.”Write down the topic of the lesson in your 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 corresponding oxides

Meaning and Application.

Safety rules when working with acids.

Composition of acids (Slide 7).

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

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

Acids – complex substances whose molecules consist of hydrogen atoms and an acid residue.

Classification of acids

A) by the presence of oxygen . (Slide 8)

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

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

The presence of oxygen or its absence is one of the signs of the classification of acids. According to this criterion, acids are divided into two groups:oxygen-free 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 according to certain criteria. What do you think this sign is?

Basicity – number of hydrogen atoms in an 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 an ion's charge has its own characteristics.

B) 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 degree of oxidation 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 H 3 RO 4 → P 2 ABOUT 5 - phosphoric acid

(+1) 3 +x + (−2) · 4 = 0

x − 5 = 0

X = + 5

1 + 3 − 2 +3 − 2

N 3 RO 3 → P 2 ABOUT 3 - phosphorous acid

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

N 2 SO 4 → SO 3 НNO 3 → N 2 ABOUT 5

N 2 SO 3 → SO 2 НNO 2 → N 2 ABOUT 3

Nomenclature of acids

Anoxic acids:

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

and the words "hydrogen acid"

HCl– hydrochloric acidN 2 S – hydrosulphide acid

Oxygen-containing acids:

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

If the element exhibitshigher CO(equal to group number)

+6

– “-n” and the ending “-aya”:H 2 SO 4

sulfuric acid

If element CO below highest +4

– “-ist” and the ending “-aya”:H 2 SO 3

sulfurous acid

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

Acids in nature

Acids in human life

In the human body

In cooking food

In medicine

In the national economy

Acid rain

Safety rules when working with acids (Slide 15-16).

In the 19th century, the scientist Justus Liebig lived and worked in Germany. He was an experimenter from God, from an early age he enthusiastically helped his father prepare varnishes, paints and medicines. One day, during a Greek lesson, Liebig's backpack with mercury fulminate exploded. The father, making sure that the boy was not cut out for the gymnasium, apprenticed him to a pharmacist. A few months later, the thirteen-year-old chemist knew better than the teacher how to compound medicines. After another explosion he was kicked out, but he did not give up his studies in chemistry and at the age of 23 he became a professor at the University of Giessen. This is how Karl Vogt, a chemist who worked with Liebig, describes one case. “Liebig enters, holding a bottle with a ground stopper in his hands. “Come on, bare your hand,” he says to Vogt and touches his hand with a wet cork. “Isn’t it true, it burns? – Liebig asks calmly. “I just got 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 your sleeves, pour no more than 1-2 ml of solutions, holding the jar with the label facing up.)

? How can you determine acid without resorting to extreme methods?

Consolidation of knowledge

Laboratory experience

INSTRUCTION CARD:
Form of work: steam room.
Operating time – 8-10 minutes.
Exercise:
Study the color of indicators in acidic environments.
Equipment and reagents:
3 test tubes with hydrochloric acid 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 your skin, wash it off with a stream of water.
Conducting the experiment and reporting the results:

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

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

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

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

Effect of acids on indicators

Discussion of results and formulation of conclusions:

What indicators changed their 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 the same; which means that all acids have similar properties.
? What is this connected with?(With the presence of hydrogen atoms).

If you have time. Task on slide 18

Summarizing. Reflection.

Summing up the lesson. Grading.

Continue the sentence

Today in class I learned...

I learned…

It was not clear to me...

This is a lesson for me...

It sparked 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 8th grade

Fall in love with chemistry from the first lesson... Chemistry is not an easy science, because it is not for nothing that they begin to study it only in the 8th grade, when schoolchildren already have certain knowledge of mathematics, physics, biology, geography, etc. But other subjects and their teachers also managed to win the hearts of schoolchildren. Therefore, a chemistry teacher is in a situation where he needs to make schoolchildren fall in love with his science at first sight, from the first lesson. I propose the development of the first chemistry lesson in the 8th grade. This lesson should show students that chemistry is an interesting, fascinating science, but at the same time it requires a serious attitude and a lot of hard work. During the lesson I use various forms of working with students: conversation, quiz, game, laboratory experiments, demonstration experiment, story, watching a video. The lesson is accompanied by a computer presentation, demonstration of video clips from the history of science, and performances performed by members of the chemical section of the NOU (scientific association of students). During the lesson, it is necessary to involve as many students in the class as possible, give them the opportunity to answer something, complete a task or experience - to express themselves. Eighth-graders typically perceive material through images, through their own impressions of independent activity, which is important to use to develop a sustainable interest in the subject. The more channels of perception of the proposed material are used, the more information will be absorbed, and the effectiveness of learning will increase. Therefore, already in the first lesson, students should be drawn to the fact that better assimilation of the material will be facilitated by the development of skills to observe, listen, speak, think, analyze, draw conclusions, etc. Just one first chemistry lesson in the 8th grade is not enough to achieve your goals, so holiday lessons should be held periodically in different classes. The most convenient time for this is the last lesson of the quarter or half a year. The teacher must develop a whole system of activities that promote the development of cognitive interest in the subject: the first and last lessons of the school year, a chemistry week, extracurricular activities, excursions, educational institutions, participation in conferences, competitions, olympiads, etc.

Lesson objectives.Educational: introduce students to the subject of chemistry; give an idea of ​​chemistry as an exact science, not without lyricism; present points of view on the origin of the word “chemistry”; show the relationship of chemistry with other sciences.

Educational: development of cognitive interest in the subject; introducing students to the achievements of modern science and the biographies of great chemists.

Educational: nurturing love for one’s Fatherland, pride in the achievements and successes of our country in the field of science; fostering a careful 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 compulsory health insurance modules, cards with quiz questions and descriptions of substances, portraits of J.Ya. Berzelius, D.I. Mendeleev, R. Bunsen, F.A. Kekule, N.N. Beketov, S. Arrhenius, R .Wood, N.N.Zinina; racks with test tubes, chemical beakers, crucible tongs, alcohol lamp, porcelain cup, conical flask, splinter; water, ammonia solution, acetic acid solution, ethyl alcohol, gasoline, table salt, sugar, starch, flour, pieces of ice, cotton wool, river sand, sawdust, paraffin, copper sulfate, iron filings, copper shavings, red phosphorus, sulfur , solutions of KI, 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. Updating knowledge.

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

What group of sciences does the science of “chemistry” belong to?

You already know how the words “geography”, “geometry”, “biology” are translated, and how is the word “chemistry” translated?

Student answers.

3. Information.

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

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

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, devilish science (compare with witchcraft - witchcraft based on the action of evil spirits).

V) Huma(ancient Greek) – “casting” of metals; same root and Greek humos- "juice".

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

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 in the chemistry course of the 8th, 9th, 10th grades. Who wants to answer?

Quiz questions “Is chemistry really that complicated?”

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

(Exhaled air contains CO 2 .)

Why can't a gasoline fire be extinguished with water?

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

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

(Freeze into ice.)

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

(Three shirts.)

In what sea can you not drown? Why?

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

What is heavier: 1 kg of iron or 1 kg of cotton wool?

(They are equal.)

From 1 g of which metal can you draw a wire 2.5 km long?

(Made of gold.)

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

(It is forbidden.)

What does the expression “water off a duck’s back” mean?

(The feathers of waterfowl are not wetted by water.)

What metal compounds give the planet Mars a red hue?

(Iron compounds.)

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

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

For the 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 answering them, but you must tell the children that their new knowledge will be based on what they already have, acquired in other lessons, and the teacher will help deal with difficult questions.

5. Game “Guess the substance.”

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

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

Substance

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

2nd tray. In small glasses there are white solids: table salt, sugar, starch, flour, pieces of ice, cotton wool.

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

Teacher. We need three volunteers as experimenters who will try to identify the proposed substances, making sure to explain their actions.

The teacher warns students about following 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 chemist scientists.

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

Portraits of scientists are shown.

Berzelius's cook.

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

“I can’t say exactly,” she answered, “He takes a large flask with some 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 it all 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 first moistened with a phenolphthalein solution. The alkali solution is poured into a flask with phenolphthalein, the solution turns crimson. A small solution of hydrochloric acid of a higher concentration than the alkali solution is poured into a third flask, even smaller in size, and then a colored alkali solution is poured into it. In the third flask, the solution becomes discolored. And when the entire mixture is poured into a very small flask containing a little concentrated alkali solution, the solution again acquires a crimson color.

Master of suitcases.

D.I. Mendeleev loved to bind books, glue frames for portraits, and make suitcases. He usually made purchases for these works at 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 answered with respect in his voice. “This is the master of suitcases Mendeleev!”

Good friend.

One day a colleague came to see Robert Bunsen. They talked for an hour and a half. And the guest was about to leave, when suddenly Bunsen said: “You can’t 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.

One day an excited servant ran into the office of Academician N.N. Beketov: “Nikolai Nikolaevich! 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 walked into a room filled with the roar and clang of pumps and equipment, and found Wood there, engrossed in reading a crime novel. The boss's indignation knew no bounds.

- Mr. Wood! - he cried, inflamed with anger, - You... Do you allow yourself to read a detective story?!

- For God's sake, forgive me! – Wood was confused. – But with such noise, poetry is simply not perceived!

Heroic fun of Professor Zinin.

Was assault used against students in Russia? There was no gross violence, but the teachers, although rarely, used slaps on the head. The famous academician N.N. Zinin not only scolded careless students, but also beat them. Nobody was offended by this, because... was allowed to give change to the academician. But there were no hunters to take retaliatory measures. Zinin had great physical strength and could squeeze his opponent in such a hug that he could not come to his senses for a long time.

N.N.Zinin (1812–1880)

7. Do-it-yourself miracles.

On the students' desks there are racks with two test tubes.

Teacher. You yourself are excellent experimenters; with the help of simple techniques you can create miracles. Your task is to mix the contents of the test tubes with each other.

The teacher explains to students the safety rules when performing 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.

Students perform an experiment and observe the changes that occur. (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...

Game “What's in the black box?”

The class is divided into teams of 4 people.

Teacher.Assignment to the teams: based on the description of the properties, history of discovery, familiar areas of application, you need to guess what substance we are talking about. If you guess the substance on the first try, you get 5 points, on the second try - 4 points, etc. Answers are given in writing so that other teams can continue the game. If a team gives an incorrect answer, it has the right to continue the game, but receives minus 1 point.

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

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

FIRST SUBSTANCE

1) In ancient times this substance 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, perseverance, power, and was considered the guardian of youth and beauty.

(4 points.)

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

(3 points.)

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

(2 points.)

5) Widely used in everyday life, in cooking, in leatherworking, in the textile industry and others.

(1 point.)

(Answer: Table salt.)

SECOND SUBSTANCE

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

(5 points.)

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

(4 points.)

3) Products made 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 such a base metal that it was not worth working with.

(2 points.)

5) The 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 Greek. nanos– dwarf) – a billionth part of something. A field of science that studies the properties of objects measuring 10–9 m in size. Nanotechnology manipulates individual particles ranging in size from 1 to 100 nm, and also develops devices of similar sizes. Powders and suspensions have now been created that improve the performance of engines and mechanisms. Coatings made from materials made using nanotechnology prevent rust and help the material self-clean or not become 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 will be possible to design any molecules and create ultra-strong materials. In medicine, it is planned to create targeted drugs that penetrate 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 rate. Over 5 years, the volume of ice flowing into the Atlantic annually has almost doubled, which is equivalent to a rise in the level of the World Ocean by 0.5 mm per year. Antarctica from 2002 to 2005 lost an average of 152 km 3 of ice annually. By 2100, sea levels may rise by 4–6 m from current levels.

Greek and Latin inscriptions written on the stones 2,000 years ago are unreadable due to erosion. To restore the inscriptions, scientists used a fluorescence method: when X-rays bombard the surface, the atoms become excited and then return to a resting state, emitting visible light. This makes it possible to identify traces of lead or iron left by the chisel of an ancient author.

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

In the USA, a transparent polymer coating for walls has been developed to which nothing sticks. This is a Teflon type substance. It is impossible to write or draw on such a surface with paints, chalk or a felt-tip pen. The coating can be used to protect the bottoms of sea vessels from fouling and aircraft fuselages from icing.

10. Entertaining demonstration experiments.

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

The teacher demonstrates experiences.

“Smoke without fire.”

Two glasses are moistened with concentrated solutions of ammonia and hydrochloric acid, and then they are brought next to each other. They 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. A solution of sodium carbonate is poured into a porcelain mug. Then sodium carbonate is poured from the mug into each of the three glasses in turn. In the first of them, gas is rapidly released (“carbonation”), in the second a white precipitate appears (“milk”), and in the third the solution becomes crimson due to a change in the color of the indicator in an alkaline solution (“raspberry juice”).

“Fireproof scarf.”

The handkerchief is moistened in water and then in ethyl alcohol. Using crucible tongs, it is brought to a burning alcohol lamp and set on fire. Despite the huge flame, the scarf ultimately remains intact, because... the alcohol ignites and burns before the damp cloth ignites.

“Volcano on the table.”

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

11. Summing up the lesson.

Literature

Gabrielyan O.S. Chemistry. 8th grade. M.: 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 I conduct a game lesson. Chemistry at school, 1995, No. 6, p. 21.

Internet resources