Workshop in chemistry methodological development in chemistry (grade 9) on the topic. Laboratory workshop in chemistry e) concentrated solution

No. p / p

Sections, topics

Number of hours

Work program by class

10 cells

11 cells

Introduction

1. Solutions and methods for their preparation

2. Calculations by chemical equations

3. Determination of the composition of mixtures

4. Determination of the formula of a substance

5. Patterns of the course of chemical reactions

6. Combined tasks

7. Qualitative reactions

Introduction to chemical analysis.

Chemical processes.

Chemistry of elements.

Corrosion of metals.

Food chemistry.

Pharmacology.

Final conference: "The value of experiment in the natural sciences."

Total:

Explanatory note

This elective course is designed for students in grades 10-11 who choose a natural science direction, designed for 68 hours.

The relevance of the course lies in the fact that its study will allow you to learn how to solve the main types of calculation problems that are provided for by the high school chemistry course and the program of entrance exams to universities, that is, successfully prepare for the exam in chemistry. In addition, the lack of practical training is compensated. This makes classes exciting and instills skills in working with chemical reagents and equipment, develops observational skills and the ability to think logically. In this course, an attempt was made to make the most of the visibility of a chemical experiment, to enable students not only to see how substances interact, but also to measure the ratios in which they enter into reactions and are obtained as a result of the reaction.

Course objective: expansion of students' ideas about a chemical experiment.

Course objectives:

Repetition of the material discussed in chemistry lessons;

Expansion of students' ideas about the properties of substances;

· Improving practical skills and skills in solving calculation problems for different types;

· Overcoming the formal representation of some schoolchildren about chemical processes.

During the course, students improve their skills in solving computational problems, perform qualitative tasks for the identification of substances in different bottles without labels, and experimentally carry out chains of transformations.

In the course of the experiment in the classroom, five types of skills and abilities are formed.

1. Organizational skills and abilities:

drawing up an experiment plan according to the instructions;

determination of the list of reagents and equipment according to the instructions;

preparation of the report form according to the instructions;

performing the experiment at a given time, using familiar means, methods and techniques in work;

implementation of self-control according to the instructions;

knowledge of the requirements for writing the results of the experiment.

2. Technical skills and abilities:

proper handling of known reagents and equipment;

assembly of devices and installations from finished parts according to the instructions;

performing chemical operations according to the instructions;

compliance with labor safety rules.

3. Measuring skills and abilities:

work with measuring instruments in accordance with the instructions;

knowledge and use of measurement methods;

processing of measurement results.

4. Intellectual skills and abilities:

clarification of the purpose and definition of the tasks of the experiment;

putting forward a hypothesis of the experiment;

selection and use of theoretical knowledge;

observation and establishment of characteristic signs of phenomena and processes according to the instructions;

comparison, analysis, establishment of cause-and-effect relationships,

generalization of the obtained results and - formulation of conclusions.

5. Design skills and abilities:

correction of the simplest malfunctions in equipment, instruments and installations under the supervision of a teacher;

use of ready-made equipment, instruments and installations;

production of the simplest equipment, instruments and installations under the guidance of a teacher;

image of equipment, instruments and installations in the form of a picture.

Knowledge control is carried out when solving computational and experimental problems.

The result of the work on the elective course will be the performance of a test work, including the compilation, solution and experimental implementation of a calculation problem or a qualitative task: determining the composition of a substance or implementing a chain of transformations.

Introduction (1 hour)

Planning, preparing and conducting a chemical experiment. Safety precautions during laboratory and practical work. Rules for the provision of first aid for burns and poisoning with chemical reagents.

Topic 1. Solutions and methods for their preparation (4 hours)

The value of solutions in a chemical experiment. The concept of a true solution. Rules for the preparation of solutions. Technochemical scales and rules for weighing solids.

The mass fraction of a solute in a solution. Calculation and preparation of a solution with a certain mass fraction of a dissolved substance.

Determination of the volumes of solutions using volumetric utensils and the density of solutions of inorganic substances using a hydrometer. Tables of densities of solutions of acids and alkalis. Calculations of the mass of a solute from a known density, volume, and mass fraction of a solute.

Change in the concentration of a solute in a solution. Mixing two solutions of the same substance in order to obtain a solution of a new concentration. Calculations of the concentration of the solution obtained by mixing, the "cross" rule.

Demos. Chemical utensils for the preparation of solutions (glasses, conical and flat-bottomed flasks, volumetric cylinders, volumetric flasks, glass rods, glass funnels, etc.). Preparation of sodium chloride solution and sulfuric acid solution. Technochemical scales, weights. Determination of the volume of solutions of acids and alkalis using a graduated cylinder. Hydrometer. Determination of the density of solutions using a hydrometer. Increasing the concentration of the sodium hydroxide solution by partially evaporating the water and adding more alkali to the solution, checking the change in concentration with a hydrometer. Reducing the concentration of sodium hydroxide in a solution by diluting it, checking the change in concentration using a hydrometer.

Practical work. Weighing on technochemical scales of sodium chloride. Preparation of a sodium chloride solution with a given mass fraction of salt in the solution. Determining the volume of a sodium chloride solution using a graduated cylinder and determining its density using a hydrometer. Determination of the concentration of solutions of acids and alkalis by the values ​​of their densities in the table "Mass fraction of the dissolved substance (in%) and the density of solutions of acids and bases at 20 ° C". Mixing solutions of sodium chloride of various concentrations and calculating the mass fraction of salt, and determining the density of the resulting solution.

Topic 2. Calculations by chemical equations (10 hours)

The practical determination of the mass of one of the reactants by weighing or by volume, density, and mass fraction of the solute in solution. Carrying out a chemical reaction and calculating the equation of this reaction. Weighing the reaction product and explaining the difference between the practical result obtained and the calculated one.

Practical work. Determination of the mass of magnesium oxide obtained by burning a known mass of magnesium. Determination of the mass of sodium chloride obtained by reacting a solution containing a known mass of sodium hydroxide with an excess of hydrochloric acid.

Practical determination of the mass of one of the reacting substances by weighing, conducting a chemical reaction and calculating according to the chemical equation of this reaction, determining the mass or volume of the reaction product and its yield as a percentage of the theoretically possible.

Practical work. Dissolving zinc in hydrochloric acid and determining the volume of hydrogen. Calcination of potassium permanganate and determination of the volume of oxygen.

Carrying out reactions for substances containing impurities, observing the results of the experiment. Calculations with the determination of the mass fraction of impurities in a substance based on the results of a chemical reaction.

Demonstration experiment. Dissolving sodium, calcium in water and observing the results of the experiment in order to detect impurities in these metals.

Practical work. Dissolution of chalk powder contaminated with river sand in a solution of nitric acid.

Determination of the masses of reactants, carrying out a chemical reaction between them, the study of reaction products and the practical determination of a substance in excess. Solving problems to determine the mass of one of the reaction products from known masses of reactants, one of which is given in excess.

Demonstration experiment. The combustion of sulfur and phosphorus, the determination of the substance that is in excess in these reactions.

Practical work. Conducting a reaction between solutions of nitric acid and sodium hydroxide containing known masses of reactants, determining the excess of the reagent using an indicator.

Topic 3. Determination of the composition of mixtures (2 hours)

Carrying out the reaction of a mixture of two substances with a reagent that interacts with only one component of the mixture. Carrying out the reaction of a mixture of two substances with a reagent that interacts with all components of the mixture. Discussion of the results of the experiment. Solving problems for determining the composition of mixtures.

Demonstration experiment. Interaction of a mixture of zinc dust and copper filings with hydrochloric acid. Interaction of a mixture of magnesium powder and zinc dust with hydrochloric acid.

Topic 4. Determining the formula of a substance (6 hours)

The concept of the qualitative and quantitative composition of a substance. Calculation of the molecular weight of a substance based on its hydrogen density, etc. and the mass fraction of the element. Determination of the formula of a substance based on the quantitative data of the reaction products. Determination of the formula of organic substances based on the general formula of the homologous series.

Topic 5. Patterns of chemical reactions (5 hours)

The concept of thermal processes in chemical reactions. Exo- and endothermic reactions. Calculations on thermochemical equations.

Demonstration. The reaction of dilution of concentrated sulfuric acid and the preparation of ammonium chloride.

The concept of reaction rate. Factors affecting the reaction rate. Determination of the reaction rate.

Demonstration. Influence of reaction conditions on its rate.

The concept of chemical equilibrium. Ways to shift chemical equilibrium. Application of this knowledge in chemical production.

Topic 6. Combined tasks (3 hours)

Solving combined problems for different types of block C of the Unified State Examination in chemistry.

Topic 7. Qualitative reactions (3 hours)

The concept of a qualitative reaction. Determination of substances using the solubility table of acids, bases and salts, characterization of visible changes in processes. Determination of inorganic substances found in different bottles without labels, without the use of additional reagents. Implementation of transformations of inorganic and organic substances.

Demonstration experiment. Identification of solutions of iron (II) sulfate, copper (II) sulfate, aluminum chloride, silver nitrate using sodium hydroxide solution. Identification of solutions of sodium chloride, potassium iodide, sodium phosphate, calcium nitrate using a solution of silver nitrate and nitric acid.

Implementation of a chain of transformations.

Practical work. Determination in numbered bottles without labels of solutions of silver nitrate, sodium hydroxide, magnesium chloride, zinc nitrate without the use of additional reagents.

Topic 8. Introduction to chemical analysis (6 hours)

Introduction. Chemistry, man and modern society. Introduction to chemical analysis. Fundamentals of qualitative analysis. Fundamentals of analytical chemistry. Solution of typical calculation problems.

Practical work. Carrying out analysis to detect traces of blood and saliva in the issued samples. Analysis of chips and soft drinks.

Topic 9. Chemical processes (6 hours)

Characteristics of chemical processes. Chemical process, its signs. Crystals in nature. Crystallization of substances and its dependence on various factors. Chemical processes in the human body. Biochemistry and physiology.

Practical work. crystallization of matter. Growing crystals in the laboratory. Decomposition of hydrogen peroxide by blood enzymes.

Topic 10. Chemistry of elements (5 hours)

The essence of a chemical reaction. Solving problems involving substances of various classes and determining the type of chemical reaction. Chemical reactions that take place without changing the oxidation state of chemical elements. Reactions that go with a change in the degree of oxidation of chemical elements. Ion exchange reactions.

Practical work. Salt precipitation.

Topic 11. Corrosion of metals (3 hours)

The concept of corrosion. Signs of a corroded surface. Chemical and electrochemical corrosion. Corrosion protection.

Practical work. Methods for protecting metal surfaces from corrosion.

Topic 12. Food chemistry (7 hours)

Chemistry and nutrition. The importance of proteins, fats and carbohydrates for good nutrition. Factors affecting the absorption of the most important components of food. Chemical characteristics of the processes occurring in the digestive tract. "Live" and "dead" food. Chemistry of vegetarianism and meat-eating. Flavorings, preservatives, dyes and flavor enhancers.

Practical work. Determination of artificial colors in food. Isolation of proteins from biological objects.

Topic 13. Pharmacology (4 hours)

The concept of pharmacology. Recipe and prescription. Homeopathy, its chemical bases. Contraindications and side effects, chemism.

Practical work. The effect of antibiotics and nitrates on soil microflora.

Topic 14. Final conference: "The value of experiment in the natural sciences" (3 hours)

From natrochthymia to chemotherapy (drug chemistry). Chemistry of food biology. Solving typical chemical problems for entering the exam.

Requirements for learning outcomes

In the classroom of the elective course "Experimental problems in chemistry", students must strictly comply with the safety requirements for laboratory and practical work, know the rules for providing first aid for burns and poisoning with chemical reagents.

After studying the proposed course, students should:

be able to make measurements (mass of a solid with the help of technochemical scales, the volume of the solution with the help of volumetric utensils, the density of the solution with the help of a hydrometer); prepare solutions with a given mass fraction of the solute; determine the percentage concentration of solutions of acids and alkalis according to the tabular values ​​of their densities; plan, prepare and conduct simple chemical experiments related to dissolving, filtering, evaporating substances, washing and drying precipitates; obtaining and interaction of substances belonging to the main classes of inorganic compounds; determination of inorganic substances in individual solutions; the implementation of a chain of transformations of inorganic compounds;

solve combined problems, including elements of typical calculation problems:

determination of the mass and mass fraction of a solute in a solution obtained by various methods (dissolving a substance in water, mixing solutions of different concentrations, diluting and concentrating a solution);

determination of the mass of the reaction product or the volume of gas from the known mass of one of the reactants; determination of the yield of the reaction product as a percentage of the theoretically possible;

determination of the mass of the reaction product or the volume of gas from the known mass of one of the reactants containing a certain proportion of impurities;

determination of the mass of one of the reaction products from the known masses of the reactants, one of which is given in excess.

Bibliography:

1. Gabrielyan O.S. General chemistry: tasks and exercises. M.: Education, 2006.

2. Gudkova A.S. 500 tasks in chemistry. M.: Education, 2001.

3. Tasks of the All-Russian Chemistry Olympiads. M.: Exam, 2005.

4. Labiy Yu.M. Solving problems in chemistry using equations and inequalities. M.: Enlightenment, 2007

5. Magdesieva N.N., Kuzmenko N.E. Learn to solve problems in chemistry. M.: Education, 2006.

6. Novoshinsky I.I. Types of chemical problems and ways to solve them. M.: Oniks, 2006.

7. Okaev E.B. Chemistry Olympiad. Mn.: TetraSystems, 2005.

8. KIMs of the Unified State Examination in Chemistry for different years

Number

lesson

(sections, topics)

Quantity

hours

Dates

Lesson equipment

Homework

1. Introduction.

PSCE D.I. Mendeleev, portraits of scientists

Introduction.

2. Solutions and methods for their preparation

Alcohol lamp, test tube rack, test tubes, flame test wire, filter paper, evaporation cup, universal indicator paper, solutions of nitric acid, barium chloride, sodium hydroxide, lime water, silver nitrate

Mass fraction of the dissolved substance.

Molar concentration and molar concentration equivalent.

Solubility of substances.

Practical work No. 1: "Preparation of a solution of a certain concentration by mixing solutions of various concentrations."

3. Calculations by chemical equations

Alcohol lamp, tripod, tongs, spatula, beaker, test tubes, dropper, measuring cylinder, filter funnel, filter paper, solutions of nitric acid, silver nitrate, hydrochloric acid, D.I. Mendeleev's PSCE, solubility table, calculator

Determination of the mass of the reaction product from the known mass of one of the reactants.

Calculation of volume ratios of gases.

Tasks related to the determination of the mass of the solution.

Calculation of the mass, volume, amount of substance of the reaction product, if one of the reactants is given in excess.

Carrying out a reaction between substances containing known masses of reactants, determining the excess using an indicator.

Determination of the yield of the reaction product as a percentage of the theoretically possible.

Calculation of impurities in reactants.

4. Determination of the composition of mixtures

Alcohol lamp, tripod, glass, measuring cylinder, evaporation cup, filter paper, magnesium, sulfuric acid, copper (II) oxide, magnesium carbonate, sodium hydroxide, hydrochloric acid

Determination of the composition of the mixture, all components of which interact with the specified reagents.

Determination of the composition of the mixture, the components of which selectively interact with the specified reagents.

5. Determination of the formula of a substance

Derivation of the formula of a substance based on the mass fraction of elements.

The derivation of the molecular formula of a substance based on its density in hydrogen or in air and the mass fraction of the element.

The derivation of the molecular formula of a substance by the relative density of its vapors and the mass, volume or amount of the substance of the combustion products.

Derivation of the formula of a substance based on the general formula of the homologous series of organic compounds.

6. Patterns of chemical reactions

PSCE D.I. Mendeleev, solubility table, task cards

Calculations according to thermochemical equations.

The rate of chemical reactions.

chemical balance.

7. Combined tasks

PSCE D.I. Mendeleev, solubility table, task cards

Combined tasks.

8. Qualitative reactions

Wide test tube with vent tube, tripod, stopwatch, gas syringe, measuring cylinder, zinc granules and powder, dilute hydrochloric acid, hydrogen peroxide solution, manganese (IV) oxide, copper (II) oxide, zinc oxide, sodium chloride, potato slices, liver pieces.

Methods for determining inorganic and organic substances.

Experimental determination of inorganic substances.

Experimental determination of organic substances.

34 hour

The folder contains materials that will help organize a practical part in chemistry for children with disabilities and in distance learning

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MONITORING THE ACHIEVEMENT OF PLANNED RESULTS IN THE COURSE OF CHEMISTRY (FROM WORK EXPERIENCE)

Dushak Olga Mikhailovna

Regional budgetary educational institution "School of distance education", Zheleznogorsk,

Keywords: new Federal State Educational Standard, planned results, chemistry, current control, microskills

Annotation: The article describes the experience of using such forms of control as the Feedback Sheet and the List of Achievements of the Planned Results in the Chemistry course of grades 8-9.

The activity of the teacher within the framework of the new educational standard is result-oriented. The planned result of education, prescribed in the Federal State Educational Standard, is differentiated. The planned results of mastering the curricula are given in two blocks: "The graduate will learn" (basic level) and "The graduate will have the opportunity to learn" (advanced level). On the FIPI website, a teacher and a student can get acquainted with the measuring materials for the final certification of students. For the qualitative passage of the final certification, the student must master the system of concepts, subject knowledge and skills. The teacher is faced with the task of forming this knowledge and skills, creating a system for evaluating the achievement of planned results in the course of ongoing monitoring. Having studied the materials of the new Federal State Educational Standard, methodological literature, and the experience of colleagues, I set about creating my own system for tracking the effectiveness of achieving the planned results when studying the topics of the Chemistry course in grades 8-9. As a basis for the classification, I took the system considered by A.A. Kaverina, senior researcher. Center for Science Education of the Institute for Education Development Strategy of the Russian Academy of Education, Ph.D.

To assess the achievement of the planned results, it is necessary to develop criteria. Criteria should be developed correctly, accessible and reflect the gradual assimilation of knowledge and skills to create comfortable conditions for the child to acquire cognitive experience, to move from the zone of actual development to the zone of proximal development and beyond. During the last academic year, I developed and tested algorithms for completing tasks, feedback sheets, achievement sheets for some sections of the Chemistry course in grades 8-9.

During the educational process, at the beginning of the study of each topic, students are offered a list of concepts for the final test and criteria for evaluating their educational results in the form of skills and micro-skills, reflected in the Feedback Sheets and assignments for them. In the course of studying the topic, the results are noted in the Achievements List. Tasks can be used both when studying a new topic, and when consolidating and summarizing educational material. For example, in the Variety of Chemical Reactions section, skills are worked out: to draw up equations for the electrolytic dissociation of acids, alkalis, salts; compose full and reduced ionic equations of exchange reactions. The feedback sheet that the student receives contains micro-skills for the phased completion of the task, which is also attached. To evaluate their own results, I offer students a simple scale: I can + I can’t-.

Task number 1 Compose salt formulas using the valency value for the metal and acid residue; name the substances, write the dissociation equation (the text of the assignment is given as a fragment).

Evaluation criteria: I can + I can't -

Task number 2 Compose formulas for the proposed substances, determine the class, write the dissociation equations for these substances: potassium chloride, silver nitrate, sodium carbonate, magnesium sulfate, lead nitrate, potassium sulfide, potassium phosphate (the text of the assignment is given as a fragment).

Feedback sheet _____________________________________________ Full name

Topic: Ionic Equations BASIC!

Evaluation criteria: I can + I can not -

Task number 3 Write the equations for the exchange reactions between the proposed pairs of substances. Equalize, compose a complete and reduced ionic equation (the text of the task is given as a fragment).

Feedback sheet ____________________________________________ Full name

Topic: Ionic Equations BASIC!

Evaluation criteria: I can + I can not -

After the successful completion of tasks of the basic level, the student gets the opportunity to complete tasks of an advanced level, which indicates the formation of the ability to apply the acquired knowledge to solve educational and practical problems in a changed, non-standard situation, as well as the ability to systematize and generalize the knowledge gained.

For example, when performing task number 3 onelevated level, the student can formulate a conclusion about the case in which the ion exchange reactions proceed to the end. Using the Table of Solubility of Acids, Bases and Salts, write examples of molecular equations for these abbreviated ionic equations: Ba 2+ + SO 4 2- \u003d BaSO 4; CO 3 2- + 2H + = H 2 O + CO 2, etc.

Such an organization of the educational process showed a number of advantages: the possibility of an individual trajectory in the assimilation of the topic, the criteria for evaluating the results of work that are understandable to the child and his parents. In the future, it is planned to continue work on the development of assignments for other sections of the course.

Bibliographic list:

1. Kaverina A.A. Chemistry. Planned results. Job system. Grades 8-9: a manual for teachers of educational institutions / A.A. Kaverina, R.G. Ivanova, D.Yu., Dobrotin; ed. G.S. Kovaleva, O.B. Loginova. – M.: Enlightenment, 2013. – 128 p. – (We work according to new standards)

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Grade 8 Practical work on the topic:Soil and water analysis

Experience 1

Mechanical soil analysis

In a test tube (or vial) place the soil (the column of soil should be 2-3 cm). Add distilled water(boiled) the volume of which should be 3 times the volume of the soil.

Close the test tube with a stopper and shake thoroughly for 1-2 minutes, and then arm yourself with a magnifying glass and observe the sedimentation of soil particles and the structure of sediments. Describe and explain your observations.

Experience 2

Obtaining a soil solution and experiments with it

Prepare paperfilter (or cotton, bandage), insert it into the funnel fixed in the tripod ring. Substitute a clean, dry test tube under the funnel and filter the mixture of soil and water obtained in the first experiment. The mixture should not be shaken before filtering. The soil will remain on the filter, and the filtrate collected in the test tube is a soil extract (soil solution).

Place a few drops of this solution on a glass plate and use tweezers to hold it over the burner until the water evaporates.(just leave on the battery).What are you watching? Explain.

Take two litmus papers (red and blue)(if there is!), apply soil solution to them with a glass rod. Draw a conclusion based on your observations:

1. After evaporation of water on the glass ………..

2. Universal litmus paper will not change color if the solution is neutral, will turn red if it is acidic, and blue if it is alkaline.

Experience 3

Determination of water transparency

For the experiment, you need a transparent flat-bottomed glass cylinder.(tumbler) diameter 2-2.5 cm, height 30-35 cm You can use a 250 ml measuring cylinder without a plastic stand. SPECIFY YOUR GLASS DIMENSIONS

We recommend that you test first with distilled water and then with water from a reservoir and compare the results. Place the cylinder on the printed text and pour in the test water, making sure that you can read the text through the water. Note at what height you won't see the font. Measure the heights of the water columns with a ruler. Draw conclusions:

The measured height is called the level of visibility.

If the level of visibility is low, then the reservoir is heavily polluted.

Experience 4

Determination of the intensity of the smell of water

conical flask(jar) fill 2/3 full volume of the investigated water, close tightly with a cork (preferably glass) and shake vigorously. Then open the flask and note the nature and intensity of the smell. Rate the intensity of the smell of water in points, using table 8.

Use table 8 (p. 183).

MAKE A GENERAL CONCLUSION

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Section V Experimental Chemistry

• Reveal during the performance of a chemical experiment signs indicating the occurrence of a chemical reaction
• Conduct experiments on the recognition of aqueous solutions of acids and alkalis using indicators

Related concepts:

Chemical phenomenon (reaction), experiment, acid, alkali, signs of a chemical reaction, solution, indicators

Signs of a chemical reaction:

Discoloration, odor, precipitation or dissolution, evolution of gas, emission or absorption of heat and light

Task number 1

Feedback sheet __________________________________________ Full name

Topic: Experimental chemistry. Signs of chemical reactions

Evaluation criteria: I can + I can't -

Federal Agency for Education Tomsk State University of Architecture and Civil Engineering

I.A. KURZINA, T.S. SHEPELENKO, G.V. LYAMINA, I.A. BOZHKO, E.A. VAYTULEVICH

LABORATORY WORKSHOP ON GENERAL AND INORGANIC CHEMISTRY

Tutorial

Publishing House of Tomsk State University of Architecture and Civil Engineering

UDC 546 (076.5) L 12

Laboratory workshop on general and inorganic chemistry [Text]: textbook / I.A. Kurzina, T.S. Shepelenko, G.V. Lyamina [and others]; under. ed. I.A. Kurzina.

Tomsk: Publishing House Vol. state architect.-builds. un-ta, 2006. - 101 p. – ISBN 5–93057–172–4

AT the textbook provides theoretical information on the main sections of the general course

and inorganic chemistry (classes of inorganic compounds, basic laws and concepts of chemistry, energy effects of chemical reactions, chemical kinetics, solutions, electrochemistry, basic properties of some elements of groups I - VII of the periodic system of D.I. Mendeleev). The experimental part describes the methods of performing seventeen laboratory works. The manual will allow students to prepare more effectively for practical classes and save time when preparing reports on laboratory work. The textbook is intended for all specialties of all forms of education.

ill. 14, tab. 49, bibliography. 9 titles Published by decision of the editorial and publishing council of TGASU.

Reviewers:

Associate Professor of the Department of Analytical Chemistry, KhP TSU, Ph.D. V.V. Shelkovnikov Associate Professor of the Department of General Chemistry, TPU, Ph.D. G.A. Voronova Associate Professor of the Department of Chemistry, TSUAE, Ph.D. T.M. Yuzhakov

university, 2006

INTRODUCTION

Chemistry refers to the natural sciences that study the material world around us. The material objects that make up the subject of study of chemistry are chemical elements and their various compounds. All objects of the material world are in continuous motion (change). There are various forms of motion of matter, including the chemical form of motion, which is also the subject of study of chemistry. The chemical form of the motion of matter includes a variety of chemical reactions (transformations of substances). So, Chemistry is the science of the properties of chemical elements and their compounds and the laws governing the transformations of substances.

The most important applied aspect of modern chemistry is the purposeful synthesis of compounds with the necessary and predicted properties for their subsequent application in various fields of science and technology, in particular, to obtain unique materials. It should be noted that chemistry as a science has come a short way to the present day - approximately since the 60s of the XIX century. Over a period that lasted a century and a half, a periodic classification of chemical elements and the doctrine of periodicity were developed, a theory of the structure of the atom, a theory of chemical bonding and the structure of chemical compounds were created, such important disciplines for describing chemical processes as chemical thermodynamics and chemical kinetics appeared, quantum chemistry arose, radiochemistry, nuclear physics. Chemical research has expanded so that certain branches of chemistry - inorganic chemistry, organic chemistry, analytical chemistry, physical chemistry, polymer chemistry, biochemistry, agricultural chemistry and others - became self-

solid independent sciences.

This teaching aid includes two main sections of modern chemistry: "General Chemistry" and "Inorganic Chemistry". The theoretical foundations for understanding the diverse and complex picture of chemical phenomena are laid by general chemistry. Inorganic chemistry introduces substances formed by chemical elements into the concrete world. The authors tried to cover the main issues of the general chemistry course in the shortest possible form. Considerable attention is paid to the theoretical sections of general chemistry: basic laws and concepts of chemistry, chemical thermodynamics, chemical kinetics, properties of solutions, electrochemistry. In the section "Inorganic Chemistry" the main properties of elements of groups I - VII of the periodic system of D.I. Mendeleev. The appendices give the basic physical and chemical properties of inorganic substances. This teaching aid is designed to help students master the basic principles of chemistry, acquire the skills to solve typical problems and conduct experiments in a chemical laboratory.

When conducting laboratory work, it is very important to observe safety precautions. Work with this teaching aid should begin with an acquaintance with the basic rules of work in a chemical laboratory.

RULES OF WORK IN THE CHEMICAL LABORATORY

Safety requirements before starting work:

1. Before performing laboratory work, it is necessary to familiarize yourself with the physical and technical properties of the substances used and formed during the chemical reaction, as well as with the instructions and rules for handling them.

2. Keep the workplace clean and tidy. Only the necessary tools and a workbook should be on the desktop.

Safety requirements during work:

1. The experiment should be started only when the purpose and tasks of it are clearly understood, when the individual stages of the experiment are thought out.

2. Work with poisonous, volatile and caustic substances must be carried out only in a fume hood.

3. In all work, exercise maximum caution, remembering that inaccuracy

and carelessness can lead to an accident.

4. Do not lean over a vessel with boiling liquid. The heated test tube must be held with the opening away from you, as ejection of liquid may occur. Warm the contents throughout the tube, not just from the bottom.

5. After using the reagent, it must be immediately put in place so as not to create a mess in the workplace and not mix up reagents when arranging them at the end of classes.

6. When diluting concentrated sulfuric acid, it is necessary to pour acid into water in small portions, and not vice versa.

7. It is forbidden to work with flammable substances near switched on electrical appliances and burning spirit lamps or burners.

8. You should sniff the substance by directing the vapors towards you with the movement of your hand, and not inhaling them with full breasts.

9. Do not use for experiments substance from cans, packages and droppers without labels or with illegible inscriptions.

10. If acid or alkali comes into contact with the skin, it is necessary to wash the burned area with plenty of water, and then - in case of burns with acid - 3% solution of soda, and in case of burns with alkalis - 1% solution of boric acid.

11. If the reagent gets into the eyes, rinse them with a stream of water, and in case of gas poisoning, provide the victim with fresh air.

12. In order to avoid poisoning, it is strictly forbidden to store and eat food, smoke in the working rooms of chemical laboratories.

Safety requirements at the end of work:

It is necessary to clean up everything spilled, broken and scattered from the table and floor. After completing the experiment, the workplace must be put in order. Do not throw granules and pieces of metal into the sink, but put them in a special vessel and hand them over to the laboratory assistant. No substances from the laboratory can be taken home. After finishing work, you must

thoroughly wash your hands. Report all violations of safety rules and unforeseen situations to the teacher immediately!

I have read and agree to comply with the safety regulations. Signature of the student:

Conducted briefing, checked knowledge of safety regulations Teacher's signature:

Lab #1

CLASSES OF INORGANIC COMPOUNDS

Purpose of work: to study the classes of inorganic compounds, methods for their preparation and chemical properties.

Theoretical part

All chemicals are divided into two groups: simple and complex. Simple substances consist of atoms of one element (Cl2, O2, C, etc.). The composition of the complex includes two or more elements (K2 SO4, NaOH, HNO3, etc.). The most important classes of inorganic compounds are oxides, hydroxides, and salts (figure).

Oxides are compounds consisting of two elements, one of which is oxygen. By functional features, oxides are divided into salt-forming and non-salt-forming (indifferent). Non-salt-forming called oxides that do not form hydrated compounds and salts (CO, NO, N2 O). Salt-forming oxides according to their chemical properties, they are divided into basic, acidic and amphoteric (figure). The chemical properties of oxides are presented in table. one.

Na2O; MgO CuO.

Acid oxides form all non-metals (except F) and metals with a high degree of oxidation (+5, +6, +7), for example SO3; P2 O5 ; Mn2 O7 ; CrO3 .

Amphoteric oxides form some metals in the +2 oxidation state (Be, Zn, Sn, Pb) and almost all metals in the +3 and +4 oxidation states (Al, Ga, Sc, Ge, Sn, Pb, Cr, Mn).

Table 1

Chemical properties of oxides

Amphoteric oxides

1. Amphoteric oxide + H 2 O →

2. Amph. oxide + acid. oxide → salt 2. Amph. oxide + Basic oxide → Salt

Hydroxides are chemical compounds of oxides with water. According to chemical properties, basic hydroxides, acid hydroxides and amphoteric hydroxides are distinguished (see figure). The main chemical properties of hydroxides are given in table. 2.

Basic hydroxides or bases are substances that, during electrolytic dissociation in aqueous solutions, form negatively charged hydroxide ions (OH–) and do not form other negative ions. Alkali metal hydroxides that are readily soluble in water, except for LiOH, are called alkalis. The names of the main hydroxides are formed from the word "hydroxide" and the name of the element in the genitive case, after which, if necessary, the degree of oxidation of the element is indicated in brackets by Roman numerals. For example, Fe (OH) 2 is iron (II) hydroxide.

Acid hydroxides or acids are substances that, when dissociated in aqueous solutions, form positively charged hydrogen ions (H + ) and do not form other positive ions. The names of acid hydroxides (acids) are formed according to the rules established for acids (see Appendix 1)

Amphoteric hydroxides or ampholytes are formed by elements with amphoteric properties. Amphoteric hydroxides are called like basic hydroxides, for example, Al (OH) 3 - aluminum hydroxide. Ampholytes exhibit both acidic and basic properties (Table 2).

table 2

Chemical properties of hydroxides

3. Base + Acid → Salt + H 2 O

Ba(OH)2 + H2SO4 → BaSO4 + 2H2O

Amphoteric hydroxides

1. Amph. hydroxide+Acid. oxide→Salt+H2 O 1. Amf. hydroxide+Basic oxide → Salt+H2 O

Salts are substances whose molecules consist of metal cations and an acid residue. They can be considered as products of partial or complete replacement of hydrogen in the acid by a metal or hydroxide groups in the base by acid residues.

There are medium, acidic and basic salts (see figure). Medium or normal salts are products of complete replacement of hydrogen atoms in acids with a metal or hydroxide groups in bases with an acid residue. Acid salts are products of incomplete replacement of hydrogen atoms in acid molecules by metal ions. Basic salts are products of incomplete replacement of hydroxide groups in bases by acidic residues.

The names of middle salts are made up of the name of the acid anion in the nominative case (Appendix 1) and the name of the cation in the genitive case, for example CuSO4 - copper sulfate. The name of acid salts is formed in the same way as the average ones, but at the same time the prefix hydro is added, indicating the presence of unsubstituted hydrogen atoms, the number of which is indicated by Greek numerals, for example, Ba (H2 PO4) 2 - barium dihydrogen phosphate. The names of basic salts are also formed similarly to the names of medium salts, but at the same time the prefix hydroxo is added, indicating the presence of unsubstituted hydroxo groups, for example, Al (OH) 2 NO3 - aluminum dihydroxonitrate.

Work order

Experience 1. Establishing the nature of oxides

Experience 1.1. Interaction of calcium oxide with water (A), hydrochloric acid (B), caustic soda (C). The environment of the resulting solution in the experiment (A) is checked using an indicator

(Appendix 2).

Observations: A.

Reaction equations:

Experience 1.2. Interaction of boron oxide with water (A), hydrochloric acid (B), caustic soda (C). Experiment (A) is carried out under heating. The environment of the resulting solution in the experiment (A) is checked using an indicator (Appendix 2).

Observations: A.

Reaction equations:

Experience 2 . Preparation and properties of aluminum hydroxide

Experience 2.1. Interaction of aluminum chloride with a lack of sodium hydroxide