Hydrochloric acid and its salts abstract. Nitric acid and its salts

Light intensity, connection of light intensity with light vector amplitude.

The intensity of light is called electromagnetic energy passing per unit time through a unit surface area perpendicular to the direction of light propagation. The frequencies of visible light waves lie within

\u003d (.39 4-0.75) -10 15 Hz.

Neither the eye nor any other receiver of light energy can keep track of such frequent changes in the energy flow, as a result of which they register time-averaged flow . Therefore, it is more correct to define the intensity as the modulus of the time-averaged value of the energy flux density carried by a light wave. The electromagnetic energy flux density is determined by the expression

Since a light wave is an electromagnetic wave, it is the sum of the energy of the magnetic and electric fields

(4.5)

where V is the volume occupied by the wave field.

It follows from Maxwell's equations that the vectors of the electric and magnetic fields in an electromagnetic wave are related by the relation

(4.6)

Therefore, expression (4.5) can be written as follows

From Maxwell's equations, the propagation velocity electromagnetic waves

Let's select a certain volume of the wave field in the form of a parallelepiped (Fig. 4.5)

Fig.4.5

Then , by definition of intensity

Using the expression (4.6) and assuming that in a transparent medium m = 1 we obtain

where n is the refractive index of the medium in which the wave propagates. So the tension magnetic field H proportional to tension electric field E and n:

Then the wave intensity will be determined by the expression

(4.7)

(the coefficient of proportionality is equal to) - Therefore, the intensity of light is proportional to the refractive index of the medium and the square of the amplitude of the vector of the electric field of the light wave. Note that when considering the propagation of light in a homogeneous medium, we can assume that the intensity is proportional to the square of the amplitude of the electric field strength vector () of the light wave:

However, in the case of light passing through the interface between media, the expression for the intensity, which does not take into account the factor n, leads to non-conservation of the luminous flux.

Consider a spherical light wave. The area of the spherical wave front, where R is the radius of the wave front. According to equation (4.4) we find the intensity

These expressions show that the amplitude spherical wave decreases in proportion to the distance from the source of light waves. If R is large enough, i.e. If the source is very far from the observation area, then the wave front is represented as part of a spherical surface of a very large radius. It can be considered as a plane. A wave whose wave front is represented by a plane is called a plane wave, since the energy of the wave in all planes representing the wave fronts in various moments time remains constant, then the amplitude of such a wave is constant.

.The concept of interference, superposition of harmonic waves, coherence conditions.

Light is an electromagnetic wave. The addition of waves propagating in a medium is determined by the addition of the corresponding oscillations. Consider the simplest case of the addition of electromagnetic waves (oscillations):

1) their frequencies are the same,

In this case, for each point of the medium in which the waves are added, the amplitude of the resulting wave for the electric field strength is determined by vector diagram(fig.4.6)

It follows from the diagram that the resulting amplitude is determined as follows:

where d is the phase difference of the terms of the waves (oscillations).

The result of the addition of waves depends on the characteristics of the light sources and can be different.

Chemistry lesson in grade 9

Topic: "Hydrochloric acid and its salts".

Target:study the chemical properties of hydrochloric acid, and consider the applications of this acid.

Tasks:

educational - in the process of research, study the chemical properties of hydrochloric acid and get acquainted with the qualitative reaction to the chloride ion.

Educational- develop further skills in writing equations chemical reactions; learn to compare, generalize, analyze and draw conclusions.

Educational- develop cognitive activity through experiment.

Equipment and reagents: periodic system chemical elements, solubility table, test tube rack, hydrochloric acid, sodium hydroxide, silver nitrate, blue litmus, methyl orange, phenolphthalein.

Activation techniques mental activity students:

1. Analysis of educational information.

2. Disclosure intersubject communications between chemistry, physics, biology.

3. Putting forward hypotheses.

4. Analysis and drawing up generalizing conclusions.

Lesson structure.

1. organizational stage.

2. Updating of basic knowledge.

3. Learning new material.

1. Staging learning task. Goal setting.

2. “Discovery” of new knowledge by children.

3. Studying the methods of obtaining and properties of hydrochloric acid ..

4. Physical education.

5. Laboratory experiment No. 2

4. Generalization and systematization of knowledge.

5. Homework.

6. Summing up the lesson. Reflection.

During the classes.

1. organizational stage.

2. Updating of basic knowledge.

Greeting students, creating emotional mood and motivation to learn new material. In the last lesson, we met with gaseous substance- hydrogen chloride.

1. What is the formula of hydrogen chloride?

2. How is hydrogen chloride produced? Write the equations of chemical reactions.

3. What are the properties and uses of hydrogen chloride?

4. What is formed if hydrogen chloride is dissolved in water?

3. Learning new material.

Teacher. Indeed, when hydrogen chloride is dissolved in water, hydrochloric acid is formed.And thereforeThe topic of our lesson is “Hydrochloric acid and its properties”. Let's define the goals of our lesson together. The motto of our lesson will be the words of Goethe:"Just knowing is not everything, knowledge must be used."

You will have to show how you can use your knowledge in different situations. First, let's remember what we know about acids. So the first question is:

1) What is an acid?

2) From the biology course, remember where hydrochloric acid is found in the human body?

3) What do acids taste like?

4) How do you work with acids?

Teacher. Let's start our acquaintance with hydrochloric acid by studying how to obtain it.

Getting hydrochloric acid:

1. In industry, it is obtained by burning hydrogen in chlorine and dissolving the reaction product in water.

2. In the laboratory H2SO4 + 2NaCl → 2HCl + Na2SO4

Physical properties:

concentrated hydrochloric acid ( mass fraction hydrogen chloride is 37%) - it is a colorless solution, strongly fuming in humid air, with a pungent odor due to the release of hydrogen chloride. (slide 3 video of the experiment "Properties of fuming hydrochloric acid")

This gas is easily soluble in water: up to 450 volumes of hydrogen chloride - in one volume of water. In a test tube, hydrochloric acid is formed - a solution of hydrogen chloride in water.

Chemical properties:

1) Changing the color of the indicator (litmus - red)

2) Interacts with metals (if the metal is in the series compiled by N.N. Beketov to hydrogen, then hydrogen is released and a salt is formed.

Exclusion of HNO3 (other gases are released)

Mg + 2HCl → MgCl2 + H2

2 Al + 6 HCl → 2 AlCl 3 + 3 H 2

Cu + HCl →

3) Interacts with the main and amphoteric oxides:

MgO + 2HCl → MgCl2 + H2O

ZnO + 2 HCl → ZnCl2 + H2O

4) Interacts with bases:

HCl + KOH → KCl + H2O

3 HCl + Al (OH) 3 → AlCl 3 + 3 H 2 O

5) It interacts with salts (in accordance with a number of acids, each previous acid can displace the next one from the salt), another acid and another salt are formed.

CaCO3 + 2HCl → CaCl2 + H2O + CO2

6) Interacts with oxidizing agents (MnO2, KMO4, KClO3)

6HCl + KClO3 = KCl + 3H2O + 3Cl2

7) Interacts with silver nitrate, precipitates white color which is insoluble in water or acids.

HCl + AgNO3 → AgCl↓ + HNO3

Silver nitrate is a reagent for hydrochloric acid and its salts i.e. used as qualitative reaction, to recognize chloride ions.

Laboratory experience No. 2.(students do laboratory experience, getting acquainted with the qualitative reaction to chloride ions)

Subject. Qualitative reactions to hydrochloric acid and its salts.

Working process.

Safety briefing.

In test tubes with a solution of hydrochloric acid and sodium chloride, add a few drops of a solution of silver nitrate AgNO3 (qualitative reaction for chloride ion Cl-). What are you watching? Write reaction equations in molecular and ionic form.

Reaction equations: HCl + AgNO3 =

NaCl + AgNO3 =

At the end of the work, students write down the conclusion.

The use of hydrochloric acid and its salts:

Hydrochloric acid is part of the gastric juice and promotes the digestion of protein foods in humans and animals.

Hydrogen chloride and hydrochloric acid are used to produce drugs, dyes, solvents, and plastics.

The use of basic salts of hydrochloric acid:

KCl - fertilizer, also used in glass and chemical industry.

HgCl2 - sublimate - poison, used for disinfection in medicine, for dressing seeds in agriculture.

NaCl- salt- raw materials for the production of hydrochloric acid, sodium hydroxide, hydrogen, chlorine, bleach, soda. It is used in the leather and soap industries, in cooking and canning.

ZnCl2 - for wood impregnation against decay, in medicine, when soldering.

AgCl - used in black and white photography, as it has photosensitivity - decomposes in the light to form free silver: 2AgCl => 2Ag + Cl2

4. Generalization and systematization of knowledge.

Tasks for repetition and consolidation

No. 1. Carry out the transformations according to the scheme:

HF → F2 → FeF3 → Fe(OH)3 → Fe2O3 → FeF3 → F2

No. 2. Substances given:

Ca, Au, Fe(II), ZnO, FeO, LiOH, Fe(OH)3, FeSO4, Na2CO3, Fe(NO3)2

Which of the following substances will react with hydrochloric acid.

5. Homework. §15, ex. No. 2,3, TK p.58.

6. Summing up the lesson. Reflection.

Teacher : Today in the lesson we deepened our knowledge of acids, getting acquainted in more detail with hydrochloric acid. And now I would like you to evaluate the level of your knowledge after this lesson. Put a "+" next to the statements that you think are true for yourself.

1) After the lesson, I began (a) to know more.

2) Deepened (a) knowledge on the topic, I can apply them in practice.

3) At the lesson there was something to think about.

4) I received (a) answers to all questions that arose during the lesson.

5) At the lesson, I worked in good faith and achieved the objectives of the lesson (la).

Teacher: At the end of the work, please raise the hands of those who put

5 "+"; 4 "+"; 3

Lesson in grade 8 on the topic: Hydrochloric acid and its salts.

Purpose: to study the chemical properties of hydrochloric acid, and consider the scope of this acid.
Tasks:
Educational - in the process of research, study the chemical properties of hydrochloric acid and get acquainted with the qualitative reaction to the chloride ion.
Developing - to develop further skills in composing equations of chemical reactions; learn to compare, generalize, analyze and draw conclusions.
Educational - to develop cognitive activity through experiment.

Type of lesson: a lesson in the assimilation of new knowledge.

Teaching method: explanatory-illustrative, problem-search, practical work, the use of ICT.
Organizational forms: conversation, practical work, student messages.

Equipment and reagents: periodic table of chemical elements, solubility table, rack with test tubes, hydrochloric acid, sodium hydroxide, silver nitrate, copper, magnesium, aluminum, blue litmus, methyl orange, phenolphthalein.
Techniques for activating the mental activity of students:
Analysis of educational information.
Disclosure of interdisciplinary connections between chemistry, physics, biology.
Putting forward hypotheses.
Analysis and drawing up generalizing conclusions.
During the classes.

introduction teachers:
The topic of our lesson is “Hydrochloric acid and its properties”.
The motto of our lesson will be the words of Goethe:
"Just knowing is not everything, knowledge must be used."
You will have to show how you can use your knowledge in different situations. First, let's remember what we know about acids. So the first question is:
What is an acid? (a complex substance consisting of hydrogen atoms and an acid residue).
How many hydrogen atoms can there be in acids? How are they classified on this basis? (one-, two-, three-base). Give examples.
What can replace hydrogen? What does this result in? (metals; salts).
Define salt. ( Complex Substances, consisting of metal atoms and an acid residue).
Physical properties:
Concentrated hydrochloric acid (mass fraction of hydrogen chloride is 37%) is a colorless solution, strongly fuming in humid air, with a pungent odor due to the release of hydrogen chloride.
Getting hydrochloric acid:
1. In industry, it is obtained by burning hydrogen in chlorine and dissolving the reaction product in water.
2. In the laboratory H2SO4 + 2NaCl 2HCl + Na2SO4
This gas is easily soluble in water: up to 450 volumes of hydrogen chloride - in one volume of water. In a test tube, hydrochloric acid is formed - a solution of hydrogen chloride in water.
Chemical properties:
1) Changing the color of the indicator (litmus-red)
2) Interacts with metals (if the metal is in the series compiled by N.N. Beketov to hydrogen, then hydrogen is released and a salt is formed.
Exclusion of HNO3 (other gases are released)

Mg + 2HCl MgCl2 + H2 2Al + 6HCl 2AlCl3 + 3H2 Cu + HCl

Practical work
3) Interacts with basic and amphoteric oxides:

MgO + 2HCl MgCl2 + H2O ZnO + 2HCl ZnCl2 + H2O

4) Interacts with bases:

HCl + KOH KCl + H2O 3HCl + Al(OH)3 AlCl3 + 3H2O

5) It interacts with salts (in accordance with a number of acids, each previous acid can displace the next one from the salt), another acid and another salt are formed.
HNO3
H2SO4, HCl, H2SO3, H2CO3, H2S, H2SiO3

·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
·
H3PO4

CaCO3 + 2HCl CaCl2 + H2O + CO2

6) It interacts with silver nitrate, a white precipitate forms, which is not soluble in either water or acids.

HCl + AgNO3 AgCl + HNO3

Silver nitrate is a reagent for hydrochloric acid and its salts i.e. used as a qualitative reaction to recognize chloride ions.
Practical work

7) Interacts with oxidizing agents (MnO2, KMO4, KClO3)

6HCl + KClO3 = KCl + 3H2O + 3Cl2
Conclusion: in all the reactions we studied, chlorides were obtained - salts of hydrochloric acid.

We turn to the study of salts of hydrochloric acid, which are called chlorides.
Salts of hydrochloric acid are chlorides.
Receipt:
1. Interaction of metals with chlorine.
2Fe + 3Cl2 2FeCl3
2. Interaction of hydrochloric acid with metals.
Mg + 2HCl MgCl2 + H2
3. Interaction of hydrochloric acid with oxides
CaO + 2HCl CaCl2 + H2O
4. Interaction of hydrochloric acid with hydroxides
Ba(OH)2 + 2HCl BaCl2 + 2H2O
5. Interaction of hydrochloric acid with some salts
Pb(NO3)2 + 2HCl PbCl2 + 2HNO3

Most chlorides are soluble in water (with the exception of silver, lead and monovalent mercury chlorides).

The use of hydrochloric acid and its salts:

Hydrochloric acid is part of the gastric juice and promotes the digestion of protein foods in humans and animals.
Hydrogen chloride and hydrochloric acid are used to produce drugs, dyes, solvents, and plastics.
The use of basic salts of hydrochloric acid:
KCl is a fertilizer, also used in the glass and chemical industries.
HgCl2 - sublimate - poison, used for disinfection in medicine, for dressing seeds in agriculture.
NaCl - table salt - raw material for the production of hydrochloric acid, sodium hydroxide, hydrogen, chlorine, bleach, soda. It is used in the leather and soap industries, in cooking and canning.
ZnCl2 - for wood impregnation against decay, in medicine, when soldering.
AgCl - used in black and white photography, as it has photosensitivity - decomposes in the light to form free silver: 2AgCl => 2Ag + Cl2

Tasks for repetition and consolidation

No. 1. Carry out the transformations according to the scheme:
HCl Cl2 AlCl3 Al(OH)3 Al2O3 AlCl3 Cl2
No. 2. Substances given:
Zn, Cu, Al, MgO, SiO2, Fe2O3, NaOH, Al(OH)3, Fe2(SO4)3, CaCO3, Fe(NO3)3
Which of the following substances will react with hydrochloric acid. Write the equations of chemical reactions
No. 3. Solve the problem:
How much aluminum will react with an excess of hydrochloric acid to produce 5.6 liters of hydrogen (N.O.)?

D / Z p. 49, task 4-5 p. 169.

Reflection
The teacher (together with the students evaluates the lesson, accepts their suggestions and wishes).
Guys, what did each of you learn in today's lesson?
Have you mastered the concepts: "chlorides", "inhibitor", "qualitative reaction"?
What did you like or dislike about the lesson and why?
Students answer questions, evaluate the completeness of the knowledge gained, and self-evaluate their work. Identify the most interesting and complete answers, justify their point of view.
The degree of fulfillment of educational goals is revealed.

Lesson form: collective study of new material.

Goals and objectives of the lesson:

to familiarize students with the methods of obtaining and physical properties hydrogen chloride and aqueous solution of hydrochloric acid;
systematize and deepen knowledge about chemical properties ah hydrochloric acid, to characterize the scope of its application to update knowledge about hydrochloric acid from the course of biology. Improve the ability to predict the redox properties of a substance based on its composition;
to form the ability to recognize the chloride ion;
to form the ability of students to work in groups, to develop skills and abilities when performing chemical experiment, following the safety rules;
continue development cognitive interest schoolchildren, the ability to highlight the main thing, compare, generalize, develop an ecological culture.

Preliminary preparation of the teacher consists in the selection additional literature on this topic. These can be various chemistry textbooks for schools, universities; biology textbooks, reference books, popular science literature.

Equipment. Schemes-posters "Chemical properties of acids", objects made of polymers, a device for producing hydrogen chloride, test tubes.

Reagents: crystalline sodium chloride, concentrated sulfuric acid, indicators, bases, soluble, insoluble and amphoteric, oxides, metals - zinc, copper, iron.

During the classes

I. Class Organization

(checking students' readiness for the lesson).

II. Introductory speech of the teacher

(On the demonstration table there are products made of synthetic materials: shoes, toys, paints, plastic, plastic bottles).

Teacher. What do these items have to do with hydrochloric acid?

– It turns out that we can find it in household items that seem convenient, cheap to us, and we easily, without thinking about the consequences, throw them into a landfill, where all this is then burned.

Since 1995, the world production of plastics (polymers) has doubled every 5 years, and in 2000 it exceeded 200 million tons. According to various forecasts, the global production of polymers in 2010 will exceed 300 million tons.

Demonstrative experiment (combustion of a polymer shred in a fume hood).

Yes, it smells bad. Bad smell usually contain substances harmful to health.

- By themselves, synthetic materials are safe, which cannot be said about the substances that are formed during the disposal of these polymers.

Student message: Burning one kg of polyvinyl chloride, or just PVC - and these are many types of linoleum, wallpaper, plastic bottles we get up to 50 micrograms of universal poisons that affect all living things, even in negligible concentrations. In terms of toxicity, they are superior to deadly poisons, such as curare and hydrocyanic acid, but they do not decompose into environment decades, accumulate in the upper soil layer and enter the human body mainly with food, water and air.

Dioxins are not enemy sabotage, they are 200+ types of chlorine compounds - by-products technology. The sources of these poisons are enterprises of almost all industries where chlorine is used.

Dioxins have carcinogenic (that is, causing cancer), teratogenic (that is, causing birth defects) and mutagenic (that is, affecting heredity) effects.

Teacher. Now back to our experience. As you can see, the wet purple paper has turned red. This indicates that during combustion, in addition to the above substances, hydrogen chloride is also formed.

- It turns out that when PVC is burned, hydrogen chloride is also formed. The fog and vapors of hydrogen chloride formed when interacting with air are very dangerous. concentrated acid. They irritate mucous membranes and the respiratory tract. Prolonged work in an HCI atmosphere causes catarrh of the respiratory tract, tooth decay, clouding of the cornea of the eyes, manifestation of the nasal mucosa, gastrointestinal upset, acute poisoning accompanied by hoarseness, suffocation, runny nose, cough.

In the event of a leak or spill, hydrochloric acid can cause significant environmental damage.

Firstly, this leads to the release of vapors of the substance into atmospheric air in quantities exceeding sanitary and hygienic standards, which can lead to poisoning of all living things, as well as the appearance of acid precipitation, which can lead to a change in the chemical properties of soil and water.

Secondly, it can seep into groundwater, resulting in pollution of inland waters.

Where the water in rivers and lakes has become quite acidic (PH<5) исчезает рыба. При нарушении трофических цепей сокращается число видов водных животных, водорослей и бактерий (фото).

In cities, acid precipitation accelerates the destruction of marble and concrete structures, monuments and sculptures (photo). When exposed to metals, HCI is corrosive and reacts with substances such as bleach, manganese dioxide, or potassium permanganate to form toxic chlorine gas.

Yes, it's a sad picture. Today, a reasonable person, a powerful person in his indefatigable desire to “transform the whole world, but not himself” can destroy all life on Earth. Therefore, in our time, the moral side of man's relationship to nature is of particular importance. Modern man is obliged not only to protect nature, but also to help it. The poet Martynov L.N. writes about this passionately, with pain in his heart:

I hear the voice of nature
Trying to scream
How and what did she fight?
To emerge from chaos
Maybe not in the name
Definitely us with you
But so that we become alive
Thinking beings.
And the voice of Nature says:
In your power, in your power
To keep everything from falling apart
into meaningless parts.

The relationship between chemistry and the human community has always been difficult. The existence of mankind today is unthinkable without chemistry and a variety of products and materials that can be obtained using chemical technologies. At the same time, the world around him, artificially created by man, is increasingly saturated with chemical products. Proper handling of them requires a high level of chemical knowledge. Even at home, in everyday life, one cannot do without chemical knowledge, which helps to use various substances correctly and for their intended purpose, otherwise you can pay with your health and the health of others. What will chemistry become for our world - death or salvation, depends solely on how people take advantage of its possibilities.

Let's, based on the knowledge about acids obtained in grade 8, recall their general properties.

Teacher. Based on the knowledge you have, let's look together at the methods of obtaining, properties and applications of hydrogen chloride and hydrochloric acid.

The history of the discovery of hydrochloric acid (a message from a student, Appendix 1).
Obtaining hydrogen chloride in industry.

Hydrochloric acid is obtained by dissolving hydrogen chloride in water. At present, the main industrial method for producing hydrogen chloride is its synthesis from hydrogen and chlorine, proceeding according to the equation

H 2 + Cl 2 \u003d 2HCl + 43.8 kcal.

This process is carried out by burning hydrogen in a stream of chlorine. When the resulting hydrogen chloride is absorbed by water, "synthetic" hydrochloric acid is obtained.

Teacher. We will get hydrogen chloride from the same substances that M.R. used. Glauber in 1648 by heating NaCl (crystalline table salt with concentrated sulfuric acid).

Before performing the experiments, we repeat the safety rules with the students.

a) handling alcohol
b) with acids and alkalis

2NaCl + H 2 SO 4 \u003d Na 2 SO 4 + 2HCl

Krist. conc

- Why is crystalline taken to obtain hydrogen chloride. NaCl and conc. H2SO4

Teacher. Hydrogen chloride is highly soluble in water, about 500 volumes of gas are dissolved in one volume of water.

Demonstration experience. We close the cylinder filled with hydrogen chloride with a glass plate, turn it upside down, bring it into the water and remove the plate under water, the water quickly fills the cylinder.

A solution of hydrogen chloride in water is hydrochloric acid. This can be verified with litmus.

The class is divided into groups. Each group is given tasks - Appendix 4.

Teacher. Everything said earlier about hydrochloric acid and verified in experiments can be summarized in the following scheme:

Student message. The use of HCI and its salts. ( Appendix 2)

Consolidation. Story-task on this topic (The teacher tells, Appendix 3).

Assessment of knowledge. Conclusion Each participant receives a team score. The winning team earns 5 points, the rest according to the number of correct answers. The team can nominate the most active players (1-2) for an additional point for contributing to the success of the team.

Homework assignment. Learn about the properties of hydrochloric acid.

List of used literary sources:

Volkova L.A. Habitual and amazing table salt // Chemistry for schoolchildren. - 2008. - No. 1. - P. 34.
Glinka N. L. General chemistry: Proc. allowance for universities / Ed. A. I. Ermakova. - 30th ed., Rev. - M.: INTEGRAL-PRESS, 2005. - 728 p.
Koshel P.A. Discovery of hydrochloric acid and chlorine. Material from the site him.1september.ru/articlef.php?ID=200501401
Shtrub V. Ways of development of chemistry: in 2 volumes. T. 1. Per. with him. – M.: Mir, 1984. – 239 p.
Khodakov Yu.V. Story-task in chemistry. To help the teacher. Ed. 3rd, rev. M.: Enlightenment, 1965. - 124 p.
Hovhannisyan Guide to chemistry entering universities. - M.: Higher School, 1991. - 464 p.
Savinkova E.V., Loginova G.P. Chemistry. Collection of problems 8-9 cells. - AST-Press, 2001. - 400 p.
Guzey L.S., Sorokin V.V., Surovtseva R.P. Chemistry. 8th grade. – M.: Bustard, 2003. – 288 p.
Guzey L.S., Sorokin V.V., Surovtseva R.P. Chemistry. Grade 9 – M.: Bustard, 2003. – 288 p.

Lesson in grade 8 on the topic: Hydrochloric acid and its salts.

Target : to study the chemical properties of hydrochloric acid, and consider the scope of this acid.

Tasks :

Educational - in the process of research, study the chemical properties of hydrochloric acid and get acquainted with the qualitative reaction to the chloride ion.

Developing - to develop further skills in composing equations of chemical reactions; learn to compare, generalize, analyze and draw conclusions.

Educational - to develop cognitive activity through experiment.

Lesson type : a lesson in the assimilation of new knowledge.

Teaching method Keywords: explanatory-illustrative, problem-search, practical work, use of ICT.

Organizational forms: conversation, practical work, students' messages.

Techniques for activating the mental activity of students:

Analysis of educational information.
Disclosure of interdisciplinary connections between chemistry, physics, biology.
Putting forward hypotheses.
Analysis and drawing up generalizing conclusions.

During the classes.

Introductory speech of the teacher:

The topic of our lesson is “Hydrochloric acid and its properties”. (slide 1)

The motto of our lesson will be the words of Goethe:

"Just knowing is not everything, knowledge must be used." (sl.2)

You will have to show how you can use your knowledge in different situations. First, let's remember what we know about acids. So the first question is:

What is an acid? (a complex substance consisting of hydrogen atoms and an acid residue).

How many hydrogen atoms can there be in acids? How are they classified on this basis? (one-, two-, three-base). Give examples.

What can replace hydrogen? What does this result in? (metals; salts).

Define salt. (Complex substances consisting of metal atoms and an acid residue).

Physical properties:

Concentrated hydrochloric acid (mass fraction of hydrogen chloride is 37%) is a colorless solution, highly fuming in humid air, with a pungent odor due to the release of hydrogen chloride. (slide 3 video of the experiment "Properties of fuming hydrochloric acid")

Getting hydrochloric acid:

1. In industry, it is obtained by burning hydrogen in chlorine and dissolving the reaction product in water.

2. In the laboratory H 2 SO 4 + 2NaCl → 2HCl + Na 2 SO 4

This gas is easily soluble in water: up to 450 volumes of hydrogen chloride - in one volume of water. In a test tube, hydrochloric acid is formed - a solution of hydrogen chloride in water.

Chemical properties:

1) Changing the color of the indicator (litmus-red)

2) Interacts with metals (if the metal is in the series compiled by N.N. Beketov to hydrogen, then hydrogen is released and a salt is formed.

Exception HNO 3 (other gases are released)

M g + 2HCl → MgCl 2 + H 2 2Al + 6HCl → 2AlCl 3 + 3H 2 Cu + HCl →

Practical work

3) Interacts with basic and amphoteric oxides:

MgO + 2HCl → MgCl 2 + H 2 O ZnO + 2 HCl → ZnCl 2 + H 2 O

4) Interacts with bases:

HCl + KOH → KCl + H 2 O 3HCl + Al(OH) 3 → AlCl 3 + 3H 2 O

5) It interacts with salts (in accordance with a number of acids, each previous acid can displace the next one from the salt), another acid and another salt are formed.

HNO3

H 2 SO 4 , HCl, H 2 SO 3 , H 2 CO 3 , H 2 S, H 2 SiO 3

────────────────────────

H3PO4

CaCO 3 + 2HCl → CaCl 2 + H 2 O + CO 2

6) It interacts with silver nitrate, a white precipitate forms, which is not soluble in either water or acids.

HCl + AgNO 3 → AgCl↓ + HNO 3

Silver nitrate is a reagent for hydrochloric acid and its salts i.e. used as a qualitative reaction to recognize chloride ions.

Practical work

7) Interacts with oxidizing agents (MnO 2 , KMO 4 , KClO 3 )

6HCl + KClO 3 \u003d KCl + 3H 2 O + 3Cl 2

Conclusion: in all the reactions we studied, chlorides were obtained - salts of hydrochloric acid.

We turn to the study of salts of hydrochloric acid, which are called chlorides.

Salts of hydrochloric acid - chlorides.

Receipt:

1. Interaction of metals with chlorine.

2Fe + 3Cl 2 → 2FeCl 3

2. Interaction of hydrochloric acid with metals.

Mg + 2HCl → MgCl 2 + H 2

3. Interaction of hydrochloric acid with oxides

CaO + 2HCl → CaCl 2 + H 2 O

4. Interaction of hydrochloric acid with hydroxides

Ba(OH) 2 + 2HCl → BaCl 2 + 2H 2 O

5. Interaction of hydrochloric acid with some salts

Pb(NO 3 ) 2 + 2HCl → PbCl 2 ↓ + 2HNO 3

Most chlorides are soluble in water (with the exception of silver, lead and monovalent mercury chlorides).

The use of hydrochloric acid and its salts:

Hydrochloric acid is part of the gastric juice and promotes the digestion of protein foods in humans and animals.

Hydrogen chloride and hydrochloric acid are used to produce drugs, dyes, solvents, and plastics.

The use of basic salts of hydrochloric acid:

KCl is a fertilizer, also used in the glass and chemical industries.

HgCl 2 - sublimate - poison, used for disinfection in medicine, for dressing seeds in agriculture.

NaCl - table salt - raw material for the production of hydrochloric acid, sodium hydroxide, hydrogen, chlorine, bleach, soda. It is used in the leather and soap industries, in cooking and canning.

ZnCl 2 - for wood impregnation against decay, in medicine, when soldering.

AgCl - used in black and white photography, as it has photosensitivity - decomposes in the light to form free silver: 2AgCl => 2Ag + Cl 2

Tasks for repetition and consolidation

No. 1. Carry out the transformations according to the scheme:

HCl → Cl 2 → AlCl 3 → Al(OH) 3 → Al 2 O 3 → AlCl 3 → Cl 2

No. 2. Substances given:

Zn, Cu, Al, MgO, SiO 2 , Fe 2 O 3 , NaOH, Al(OH) 3 , Fe 2 (SO 4 ) 3 , CaCO 3 , Fe(NO 3 ) 3

Which of the following substances will react with hydrochloric acid. Write the equations of chemical reactions

No. 3. Solve the problem:

How much aluminum will react with an excess of hydrochloric acid to produce 5.6 liters of hydrogen (N.O.)?

D/Z p. 49, task 4-5 p.169.

Reflection

The teacher (together with the students evaluates the lesson, accepts their suggestions and wishes).

Guys, what did each of you learn in today's lesson?

Have you mastered the concepts: "chlorides", "inhibitor", "qualitative reaction"?

Were there moments of misunderstanding?

Were we able to resolve them during the conversation?

Name the most successful answers of your comrades.

What did you like or dislike about the lesson and why?

Students answer questions, evaluate the completeness of the knowledge gained, and self-evaluate their work. Identify the most interesting and complete answers, justify their point of view.

Chemical properties: 1 . Changing the color of the indicator (litmus red) 2. Reacts with metals M g + 2 HCl → MgCl 2 + H 2 2Al + 6HCl → 2AlCl 3 + 3H 2 Cu + HCl →

Conclusion: If the metal is in the series compiled by N.N. Beketov, up to hydrogen, then hydrogen is released and a salt is formed. Exclusion of HNO 3 (other gases are released)

3. Interacts with basic and amphoteric oxides: MgO + 2HCl → MgCl 2 + H 2 O ZnO + 2 HCl → ZnCl 2 + H 2 O Salt and water are formed

4. Interacts with bases: HCl + KOH → KCl + H 2 O 3HCl + Al (OH) 3 → AlCl 3 + 3H 2 O Salt and water are formed

5. Interacts with salts A number of acids HNO 3 H 2 SO 4, HCl, H 2 SO 3, H 2 CO 3, H 2 S, H 2 SiO 3 ────────────────────────────────── ──────── H 3 PO 4 CaCO 3 + 2HCl → CaCl 2 + H 2 O + CO 2

Conclusion: In accordance with a number of acids, each previous acid can displace the next one from the salt, another acid and another salt are formed.

6. Interacts with silver nitrate HCl + AgNO 3 → AgCl ↓ + HNO 3 a white precipitate forms, which does not dissolve in either water or acids.

Conclusion: Silver nitrate is a reagent for hydrochloric acid and its salts i.e. used as a qualitative reaction to recognize chloride ions.

7. Interacts with oxidizing agents Oxidizing agents: (MnO 2 , KMnO 4 , KClO 3) 6HCl + KClO 3 = KCl + 3H 2 O + 3Cl 2

Conclusion: In all the reactions we studied, chlorides were obtained - salts of hydrochloric acid.

The use of hydrochloric acid It is part of the gastric juice and promotes the digestion of protein foods For the production of drugs, dyes, solvents, plastics.

The use of salts - chlorides KCl - fertilizer, also used in the glass and chemical industries. HgCl 2 - sublimate - poison, for disinfection in medicine, for dressing seeds in agriculture. ZnCl 2 - for wood impregnation against decay, in medicine, when soldering.

Tasks for fixing No. 1. Carry out transformations according to the scheme: HCl → Cl 2 → AlCl 3 → Al (OH) 3 → Al 2 O 3 → AlCl 3 → Cl 2 No. 2. Substances are given: Zn, Cu, Al, MgO, SiO 2, Fe 2 O 3 , NaOH, Al (OH) 3, Fe 2 (SO 4) 3, CaCO 3, Fe (NO 3) 3 Which of the following substances will react with hydrochloric acid. Write the equations of chemical reactions

No. 3. Solve the problem: How much aluminum will react with an excess of hydrochloric acid to produce 5.6 liters of hydrogen (n.o.s.)?

Homework Paragraph 49, task 4-5 p.169.