Laboratory workshop in chemistry. Laboratory work in chemistry Practical work 16 in chemistry in technical school
MINISTRY OF EDUCATION OF THE NIZHNY NOVGOROD REGION GBOU SVO "SHAKHUN AGRO-INDUSTRIAL TECHNICAL SCHOOL" LABORATORY PRACTICUM in the discipline "Chemistry" Student _________________________________________________________________ (Full name) Specialty __________________________________________________________ _______________________________________________________________ (code, name according to the Federal State Educational Standard of NiSPE) Group _________ Courses from_______ The period for which materials were presented from_______________________ 20_____ year to ______________________20______ Shakhunya, 2014 Recommended for publication by the methodological council of the State Budgetary Educational Institution of Secondary Professional Education SHAPT Protocol No. 1 dated 09/02/2013 Laboratory workshop on the chemistry course developed for students of secondary special education educational institutions students studying in technical groups. It includes guidelines for performing laboratory work in the "Chemistry" course, safety requirements in the classroom and when performing laboratory work, criteria for assessing the success of laboratory work. The main objective of the laboratory workshop on general, inorganic and organic chemistry- help students learn the most important provisions of the general chemistry course program, acquire the skills of conducting a chemical experiment in compliance with all safety rules. Developer: Natalya Vasilievna Sofronova, teacher of OOD GBOU SPO SHAPT Safety requirements when working in the chemistry classroom ecological foundations environmental management 1. General requirements for student behavior in the classroom. 1.1. Enter the chemistry classroom and laboratory only with the permission of the teacher. 1.2. Enter and exit the office calmly, so as not to accidentally knock over chemical glassware, equipment, or reagents on the table. 1.3. Occupying in the office is always the same workplace, do not move to another place without the permission of the teacher. 1.4. Maintain cleanliness and order in your workplace. 1.5. There should be nothing unnecessary on the laboratory bench while working. It may contain a textbook, notebook, writing instruments, reference book. 1.6. Work while sitting, quickly, but without unnecessary haste, and maintain silence while working. 2. Safety requirements before starting work. 2.1. Only do those chemical experiments, which are agreed upon with the teacher, under his supervision or the supervision of a laboratory assistant. 2.2. Do not start work until you have checked whether everything necessary for the experiments is available, and the sequence of performing each of them has been thought out. 2.3. When heating solutions in a test tube, use a wooden holder. 2.4. Do not taste any substances. 3. Safety requirements during operation. 3.1. Follow the rules for handling reagents, chemical glassware, and laboratory equipment. Know the safety precautions when working in a chemistry room. 3.2. Carefully read the label on the jar of the substance you are using for the experiment. 3.3. Take reagents for experiments in the quantities specified in the instructions. 3.4. If the instructions do not indicate what mass or volume of the substance should be taken, then take the dry substance in such an amount that it just covers the bottom of the test tube, the solution so that it takes up no more than 1/6 of the volume of the test tube. 3.5. The remainder of the taken reagent must not be poured back into the vessel where it was stored. It should be drained (poured) into a separate jar. 3.6. When pouring liquids, take the container with reagents so that the label is directed towards the palm of your hand, remove a drop from the edge of the neck of the container, otherwise the liquid will flow down the glass, spoil the label, and may damage the skin of your hands. 3.7. Immediately close the container from which the reagent was taken with a stopper and place it in place. 3.8. Do not look into a test tube in which a liquid is being heated, and do not lean over a vessel into which any liquid is being drunk, because tiny drops may get into your eyes. 3.9. Sniff all substances carefully, do not lean over the test tube and do not inhale deeply, but direct the vapor or gas towards yourself with hand movements. 4. Safety requirements after completion of work. 4.1. Clean up your work area. 4.2. Check that the water taps are closed. 4.3. Be sure to wash your hands thoroughly. 5. Safety requirements in emergency situations. 5.1. Caution should be exercised when working with acids. You especially need to take care of your eyes. If acid gets on your hands, wash it off immediately with plenty of water. 5.2. Getting even a dilute alkali solution into your eyes can lead to irreversible loss vision. If an alkali solution gets on your hands, immediately wash it off with plenty of water until the soapy feeling disappears. 5.3. Be especially careful when working with heating devices. 5.4. Place flammable items on a ceramic or spiral rack. 5.5. To stop the burning of the alcohol lamp, you need to cover it with a cap (you cannot blow it out!). I am familiar with safety precautions when working in the chemistry classroom and the ecological fundamentals of nature management. _____________________________ Criteria for assessing the performance of laboratory work in chemistry Laboratory work is assessed by the teacher as in a lesson: skills in preparing and conducting a chemical experiment, knowledge of safety precautions, possession of basic theoretical knowledge necessary for competent conduct of the experiment and drawing up a report on laboratory work - and on the result of the work, namely on the report in workbook. Used to grade work rating system, which involves scoring various skills and abilities of students, confirmed by them during laboratory work. 1. The work was completed in accordance with all safety rules (5 points) 2. The experiment was carried out correctly: the necessary substances were taken, in the correct proportions, the execution procedure was followed (10 points) 3. The report was prepared in accordance with the requirements, correctly, accurately, the reaction equations were written down , observations, conclusion (5 points). 4. Responses received Control questions, additional problems solved (5 points) 5. Repeated laboratory work (2 points) Thus, maximum amount The points that a student can receive for completing laboratory work are 25 points. A grade of "5" is given for 24-25 points scored "4" for 20-23 points "3" for 15-19 points "2" for less than 15 points Report form laboratory workshop in the workbook No. l/r Topic Date of delivery Date of control Evaluation Signature 1. Testing salt solutions with indicators. Hydrolysis of salts.2. General properties of metals. Properties of oxides and hydroxides of iron and copper.3. Qualitative reactions to chloride, sulfate, phosphate, carbonate anions.4. Solving experimental problems in inorganic chemistry.5. Qualitative determination of carbon, hydrogen and chlorine in organic substances.6. Chemical properties of carboxylic acids.7. Recognition of plastics and chemical fibers.8. Solving experimental identification problems organic compounds. Laboratory work No. 1 Testing salt solutions with indicators. Hydrolysis of salts Purpose of the work: to study the nature of hydrolysis of salts in aqueous solutions using indicators. Reagents: litmus, phenolphthalein, solutions of sodium chloride, potassium carbonate and aluminum sulfate, sodium sulfate, barium chloride, hydrochloric acid. Instruments and equipment: test tubes, universal indicator paper, test tube rack, pipettes. Progress: I. Investigate the nature of hydrolysis of salts in aqueous solution. Record the test results in the table. Salt solutionPhenolphthaleinLitmusUniversal indicator paperNaCl K2CO3 Al2(SO4)3 Compose ionic equations hydrolysis of salts, indicating the nature (acidic, alkaline or neutral) of solutions. 1. ___________________________________________________________________________________________________________________________________________________________________________________________________________________ 2. ___________________________________________________________________________________________________________________________________________________________________________________________________ 3. ___________________________________________________________________________________________________________________________________________________________________________________ II. Experimental task. Three test tubes with numbers contain solutions of substances: sodium sulfate, potassium carbonate, sodium chloride. Determine which test tube contains which salt using two reagents. Reflect the progress of solving the problem in the table: Substance Reagent No. 1 Observation Reagent No. 2 Observation Test tube No. K2CO3Na2SO4NaCl Control questions: 1. What (strong or weak) bases and acids are the salts studied in experiment I formed? ______________________________________________________________________________________________________________________________________________________________________________________________________________________________ 2. Which salts do not undergo hydrolysis? Why? ___________________________________________________________________________________________________________________________________________________________________________________________________________________ Conclusion: ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Assessment: Teacher: Laboratory work No. 2 General properties of metals. Properties of oxides and hydroxides of iron and copper Purpose of work: Carry out chemical reactions, confirming the general properties of metals. Consider the properties of oxides and hydroxides of iron and copper. Reagents: hydrochloric acid, magnesium (powder), zinc (granules), copper, iron (II) sulfate, potassium hydroxide, hydrogen peroxide, sulfuric acid, copper(II) chloride. Instruments and equipment: test tubes, alcohol lamp, matches, spoon for solid reagents, pipettes, holder, test tube rack. Progress of work: I. Displacement of hydrogen from an acid solution by metals. Name of metalDescription of experimentObservationReaction equationMg ________________________ ______________ _______________________Zn ________________________ ______________ ______________________Cu ________________________ ______________ ______________________ II. Preparation and properties of iron hydroxides. Name of experiment Description of experiment Observation Reaction equation 1. Preparation of iron (II) hydroxide ___________________ ______________ ______________________2. Oxidation of iron(II) hydroxide to iron(III) hydroxide ___________________ ______________ ______________________3. Interaction of iron (III) hydroxide with acids ___________________ ______________ ____________________________________________ III. Preparation and properties of copper(II) oxides and hydroxides. Name of experiment Description of experiment Observation Reaction equation 1. Preparation of copper (II) hydroxide ___________________ ______________ ______________________2. Preparation of copper (II) oxide ___________________ ______________ ______________________3. Interaction of copper (II) hydroxide with acids ___________________ ______________ ____________________________________________ Test question: Which of the following metals will interact with iron (III) chloride: a) Al; b) Zn; c) Ag? Write the equations for the corresponding reactions. __________________________________________________________________________________________________________________________________________________________________________________________________________________________ Conclusion: __________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Assessment: Teacher: Laboratory work No. 3 Qualitative reactions to chloride, sulfate, phosphate, carbonate anions. Purpose of the work: to learn to recognize various inorganic salts using qualitative reactions. Reagents: sodium chloride, barium chloride, potassium orthophosphate, aluminum sulfate, potassium sulfate, sulfuric acid, potassium carbonate, silver nitrate. Instruments and equipment: test tube rack, test tubes, pipettes. Work progress: I. Carry out qualitative reactions for chloride, sulfate, phosphate, and carbonate anions using available reagents. Enter the results of the experiments in the table: Experiment No. Description of the experiment Observations Reaction equation in molecular form Reaction equation in ionic form 1.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 2.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 3.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 4.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ II. Experimental task. Using available chemical reagents, recognize the issued salts: sodium chloride, phosphate, sulfate, potassium carbonate, performing a minimum number of operations. Reflect the progress of the experiment in the table. Substance Reagent No. 1 Observation Reagent No. 2 Observation Test tube No. K2CO3K2SO4K3PO4NaCl Solve the test problem: What mass of SiO2 can be reduced with coke weighing 7.5 g. with impurities of 20%? Given: Solution: Conclusion: ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Assessment: Teacher: Laboratory work No. 4 Solving experimental problems in inorganic chemistry Purpose of work: solve experimental tasks in inorganic chemistry, applying knowledge about the chemical properties of inorganic substances. Reagents: copper (II) sulfate, sodium hydroxide, hydrochloric acid, magnesium, barium chloride, potassium carbonate, potassium orthophosphate. Instruments and equipment: test tube rack, test tubes, pipettes, alcohol lamp, copper wire, matches. Progress of work: I. Substances issued: copper (II) sulfate, sodium hydroxide, hydrochloric acid, magnesium, barium chloride, potassium carbonate, potassium orthophosphate. Using these substances, you will get: A) copper (II) oxide; B) carbon dioxide; B) magnesium hydroxide. Reflect the progress of the experiment in the table: Name of experiment Description of experiment Observation Reaction equation 1. Preparation of copper (II) oxide ___________________ ______________ ______________________2. Obtaining carbon dioxide ___________________ ______________ ______________________3. Preparation of magnesium hydroxide ___________________ ______________ ______________________ II. Prove that a solution of copper (II) sulfate contains Cu+2 and SO-2 ions using a chemical experiment. Describe your observations and provide equations for the corresponding reactions. ______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Equation 1. ______________________________________________________________ Equation 2. ______________________________________________________________ Solve the test problem: Calculate the mass of iron that can be obtained from magnetic iron ore Fe3O4 when it interacts with technical aluminum weighing 114 g, with a mass fraction of impurities of 10%. Given: Solution: Conclusion: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Assessment: Teacher: Laboratory work No. 5 Qualitative determination of carbon, hydrogen and chlorine in organic substances Purpose of the work: to prove that organic matter contains atoms of carbon, hydrogen and chlorine. Reagents: calcium hydroxide solution, monochloramine solution. Instruments and equipment: paraffin candle, beaker, chemical glass, matches, test tube rack, test tubes, copper wire, rubber stopper. Progress: Carry out a chemical experiment. Record the progress of the experiment and its results in the table. Experiment No. Name of experiment Description of experiment Observations, drawing of the device, reaction equation 1. Qualitative determination of hydrogen in paraffin. ___________________________________ ___________________________________ ______________________________ 2. Qualitative determination of carbon in paraffin ___________________________________ ______________________________ 3. Qualitative determination of chlorine in monochloramine ___________________________________ ______________________________ Solve the test problem. Withdraw structural formula an alkane containing 83.3% carbon and 16.6% hydrogen. The relative vapor density of this alkane with respect to oxygen is 2.25. Given: Solution: Conclusion: ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Assessment: Teacher: Laboratory work No. 6 Chemical properties of carboxylic acids Purpose of the work: Carry out reactions confirming Chemical properties carboxylic acids. Reagents: acetic acid solution, litmus, phenolphthalein, magnesium (powder), zinc (granules), potassium hydroxide, calcium carbonate. Instruments and equipment: test tube rack, test tubes, holder, alcohol lamp, matches, pipettes. Progress: Conduct a chemical experiment. Enter the results of the experiment into the table. Experiment No. Name of experiment Description of experiment Observations, reaction equation 1. Action of the indicator on a solution of acetic acid 2. Interaction of acetic acid with magnesium ___________________________________ ______________________________ 3. Interaction of acetic acid with zinc ___________________________________ ______________________________ 4. Interaction of acetic acid with alkalis ___________________________________ ______________________________ 5. Interaction of acetic acid with salts of weaker acids ___________________________________ ______________________________ Test question: What properties of acetic acid are similar to the properties of inorganic acids? What specific properties do carboxylic acids exhibit? Confirm your answer with reaction equations. ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Conclusion: ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Assessment: Teacher: Laboratory work No. 7 Recognition of plastics and chemical fibers Purpose of the work: to recognize the given samples of plastics and fibers. Reagents: set of plastics - polystyrene, polyethylene, polymethyl methacrylate; set of fibers - cotton, wool, lavsan; acetone, nitric acid, sulfuric acid, sodium hydroxide. Instruments and equipment: crucible tongs, alcohol lamp, matches, test tube rack, test tubes. Work progress: Experiment No. Study of plastics and fibers Observation Conclusion 1. Recognition of plastics 1.1. External examination of plastics ________________________________ _____________ 1.2. Study of the relationship of samples to combustion ________________________________ _____________ 1.3. Study of the dissolution of samples in acetone ________________________________ _____________ 2. Recognition of fibers 2.1. External examination of fibers ________________________________ _____________ 2.2. Study of the relationship of samples to combustion ________________________________ _____________ 2.3. Study of the dissolution of samples in nitric acid ________________________________ _____________ 2.4. Study of the dissolution of samples in sulfuric acid ________________________________ _____________ 2.5. Study of the dissolution of samples in hydroxide sodium ________________________________ _____________Answer the control questions: 1. What are the fundamental differences between polymerization and polycondensation reactions? ____________________________________________________________________________________________________________________________________________________ 2. Write down the equation for the polymerization of butadiene -1,3 and the equation for the polycondensation of glucose. _____________________________________________________________________________________________________________________________________________________ Conclusion: _____________________________________________________________________________________________________________________________________________________________________________________________________________________ Assessment: Teacher: Laboratory work No. 8 Solving experimental problems for the identification of organic compounds Purpose of the work: using characteristic chemical reactions, solve experimental problems using organic substances. Reagents: ethyl alcohol, copper(II) sulfate, potassium hydroxide, isobutyl alcohol, glycerin, phenol solution, acetic acid, glucose solution, starch paste, bromine water, alcohol solution of iodine, calcium carbonate. Instruments and equipment: test tube rack, test tubes, alcohol lamp, holder, matches, copper wire, glass rod, pipette. Progress. 1. Starting from ethyl alcohol, get: a) aldehyde; b) carboxylic acid; c) ester. Present the result of the experiment in the form of a table: Experiment No. Name of experiment Description of experiment Observations Reaction equation 1. Oxidation of ethyl alcohol to aldehyde _________________________ ________________ ________________ 2. Oxidation of aldehyde to carboxylic acid _________________________ ________________ ________________3. Ester synthesis ______________________________ ________________ ________________2. Using qualitative reactions, recognize solutions of the following organic substances: glycerin, phenol solution, acetic acid, glucose solution, starch paste. Every Chemical substance poured into 4 test tubes numbered from 1 to 6. Carrying out successive qualitative reactions to a particular organic reagent, determine their serial number. Present the progress of the experiment in the form of a table. Name of the reaction Description of the qualitative reaction Observations Reaction equations Test tube no. 1. Qualitative reaction to phenol________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________2. Qualitative reaction to starch paste________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________3. Recognition of glycerol and glucose________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________4. Confirming the presence of acetic acid in the remaining test tube.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Solve the test problem: The mass fraction of starch in potatoes is 20%. Calculate the mass of glucose that can be obtained from starch isolated from 891 kg of potatoes. Given: Solution: Conclusion: ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Rating: Teacher: Literature 1. Gabrielyan O.S. Workshop on general, inorganic and organic chemistry: textbook. aid for students avg. prof. textbook Establishments / O.S. Gabrielyan, I.G. Ostroumov, N.M. Dorofeeva. - M.: Publishing center "Academy", 2007. 2. Kupriyanova N.S. Laboratory and practical work in chemistry grades 10-11. - St. Petersburg: Vlados, 2011. LABORATORY PRACTICUM in the discipline "Chemistry" for secondary students vocational education full-time education The publication is printed from the author's original layout according to the decision of the methodological council of the State Budgetary Educational Institution SPO SHAPT Computer typing, proofreading and editing - the author's Layout - resource center methodologist Signed for publication on 10/03/2014 Printed in resource center GBOU SPO "Shakhunsky Agro-Industrial College" 606910, Russia, Nizhny Novgorod region, Shakhunya, st. Turgeneva, 15 Risography. Paper for office equipment. (circulation 100 copies)
Report "Teaching chemistry in a technical school using specialized programs"
Chemistry, as one of the most important disciplines in the natural sciences, has great importance for the education and training of highly qualified workers and mid-level specialists.
The role of chemistry in the vocational education system is twofold. On the one hand, it is one of the main disciplines that make up the basis general education, on the other hand, chemistry greatly influences the professional training of future workers and specialists.
When preparing students for the profession “Veterinary Paramedic”, “Confectioner-Cook”, in the specialty “Mechanization” Agriculture“At the technical school I use specialized chemistry course programs.
When developing work programs, the most rational profiling method is a combined one. Its essence is that when studying individual topics, the importance of the concepts being studied is noted for future profession or specialty. But these issues are not discussed in detail; professionally significant material is separated into a separate “modular” section, which completes the chemistry course, and when studying this section, issues on the chemistry of compounds widely used in this profession are discussed in sufficient detail. At the same time, serious attention is paid to studying the influence of these compounds on environment and the human and animal body.
When studying the block “Chemistry in Agriculture” when preparing students for the specialty “Agricultural Mechanization”, it is given a brief description of a special section of chemistry - agrochemistry, provides information about the chemistry of fertilizers and the role chemical elements in the life of plants and animals.
When training veterinary assistants, much attention is paid to the role of chemistry in animal husbandry. Characteristics of some compounds are given that can increase livestock productivity, such as protein and vitamin supplements. Given general characteristics compounds included in feed for farm animals, types of feed are studied, as well as the characteristics of additives that improve the quality of feed.
When studying the blocks “Fundamentals of Organic Chemistry” and “General Chemistry”, individual topics include professionally significant questions that illustrate the use of general chemical laws to understand the fundamentals of a given profession and specialty.
So, when studying topics in general chemistry “ Dispersed systems”, “Solutions”, in organic chemistry such topics as “Monohydric and polyhydric alcohols”, “Phenols”, “Aldehydes”, “Carboxylic acids”, “Carbohydrates”, “Proteins”, the importance of this material in the preparation and use of medicines is taken into account.
The science of pharmacology is very closely related to chemistry. In his pedagogical practice I use binary lessons (chemistry-pharmacology). Basic principles of a binary lesson:
Professional orientation - content educational material has a professional orientation based on the relationship of the issues being studied (chemistry and pharmacology);
Polytechnics - students focus on the application of theoretical knowledge in production activities.
When preparing binary lessons, it is necessary to take into account that the structure of the lesson should reflect the logical sequence of learning, taking into account the place and role of the lesson in common system. A close connection between structural elements lesson. An example is conducting a binary lesson on the topic: “Glucose”.
For workers engaged in production and processing chemical compounds and food raw materials into food, issues related to the chemistry of carbohydrates, fats, and proteins are of great importance. They form the basis of food, as well as those inorganic compounds, which are part of food, or are used in the processing of raw materials from which food is prepared or used to improve the quality of food products.
This module consists of 5 topics: “Food and its chemical composition", "The role of proteins, fats, carbohydrates in human nutrition", " Organic matter, used to improve the consumer properties of food", "Inorganic substances used in the food industry to improve the quality of food products", " Food industry and environmental problems."
In my teaching practice, I pay great attention to solving various problems with professional content. Firstly, problem solving is practical use theoretical material, application scientific knowledge on practice. Secondly, solving problems is an excellent way to implement interdisciplinary and course connections, as well as communication chemical science with life. Chemical learning problem is a model problematic situation, the solution of which requires students to engage in mental and practical actions based on knowledge of the laws, theories and methods of chemistry, aimed at consolidating, expanding knowledge and developing chemical thinking.
When drawing up a work program for a specialized chemistry course, I definitely take into account laboratory and practical work integrated with similar work for the professional cycle. An example is performing laboratory work on preparing solutions. This topic is studied in the subject “Pharmacology” at the veterinary department.
The development of specialized chemistry courses for professional educational institutions with a complete (secondary) general education helps to create positive motivation for studying chemistry, since such courses visibly and clearly show the role and knowledge of chemical knowledge in the future practical activities students both at work and at home, contribute to the implementation of life safety.
Pershina Irina Vasilievna GBOU SPO "Kurganinsky Agrarian and Technological College" KKLaboratory work in chemistry - demonstration video of experiments in chemistry on the topic Organic chemistry. The content of the presented video fully complies with the mandatory minimum educational content.
In this video of 5 parts of laboratory work in organic chemistry, 70 experiments are presented to demonstrate:
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Laboratory work in chemistry - demonstration video of experiments in chemistry on the topic Inorganic chemistry: Carbon and silicon. The content of the presented video fully complies with the mandatory minimum educational content.
In the video of laboratory work in chemistry ″Inorganic chemistry. Carbon and silicon″ included 23 experiments demonstrating adsorption by coal, interaction of coal and copper (II) oxide, production of carbon (II) oxide, its combustion in air, Kipp apparatus, production of carbon monoxide (IV) in Kiryushkin’s apparatus, evaporation of dry ice in water, decomposition of calcium carbonate and sodium bicarbonate by heating, relation of quartz to heating, preparation of silicic acid gel, hydrolysis of sodium bicarbonate, sodium carbonate and sodium silicate. qualitative reaction to carbonate ion and silicate ion, partial dissolution of glass in water, samples of natural carbonates and silicates, types of glass.
Laboratory work in chemistry - video demonstration of experiments in chemistry on the topic Metals of secondary subgroups. The content of the presented video fully complies with the mandatory minimum educational content.
In the video of laboratory work in chemistry Metals of secondary subgroups, 13 experiments were demonstrated concerning:
Laboratory work in chemistry - video demonstration of experiments in chemistry on the topic Metals of the main subgroups. The content of the presented video fully complies with the mandatory minimum educational content.
In laboratory work in chemistry Metals of the main subgroups, topics related to:
Laboratory work in chemistry - video of demonstration experiments in inorganic chemistry in terms of electric current. The content of the video laboratory work in chemistry fully complies with the mandatory minimum educational content.
This video demonstrates chemical experiments on testing the electrical conductivity of substances and their solutions; electrical conductivity of metals; electrolysis of copper chloride solution; electrolysis of potassium iodide solution; electrolysis of sodium sulfate solution.
Laboratory work in chemistry - video of demonstration experiments in inorganic chemistry conducted in 9th grade secondary school. The purpose of this demonstration video of laboratory work in chemistry is to fill the gaps in the clarity of teaching the sections Halogens and Sulfur of inorganic chemistry in secondary educational institutions. The content of the video laboratory work in chemistry fully complies with the mandatory minimum educational content.
Conducting laboratory classes in chemistry
Real guidelines are intended for first-year students of secondary vocational education on the basis of basic (general) education in specialty 260807 “Technology of public catering products” and are compiled in accordance with work program academic discipline "Chemistry", developed on the basis of the Federal State educational standard. But they may also be of interest to secondary school teachers.
Laboratory work is carried out in the process of studying topics, is a consolidation of knowledge of the theoretical course and is offered as one of the forms independent work students.
In each laboratory work, the goals, their motivational characteristics, equipment, list of reagents and sequence of actions are separately identified.
General requirements for laboratory work
During laboratory work, the following rules are observed: General requirements to the behavior of students in the chemistry classroom and safety rules in the chemical laboratory. Students are required to strictly follow the recommended methodology and technique for performing the experiment.
All work is carried out under the guidance of a teacher. The teacher must plan in advance the time for completing each stage of the task. Before starting work, make
preliminary check of students' readiness for independent implementation work and provide the necessary instructions on the methods and techniques of work;
dividing students into small groups according to the availability of space and equipment;
instructions on the rules of behavior in the chemistry classroom and safety precautions when working with chemical reagents.
The quality of laboratory work is assessed by observing the student experiment, taking into account explanations and written reports. Observations of students’ work during class must be recorded.
When assessing the performance of laboratory work, it is important to take into account how students master this or that knowledge, the ability to apply knowledge in an experimental situation, the ability to formalize the results of the experiment, as well as the completion of the entire task as a whole; it is necessary to evaluate not only the results of its completion in the notebook, but also the entire process execution. The assessment for laboratory work is included in the current control.
Laboratory work No. 1
Subject"Water. Solutions. Electrolytic dissociation. Preparation of a solution of a given concentration, calculation mass fraction solute."Purpose of laboratory work consolidate the knowledge and skills of students on the topic: “Water. Solutions. Electrolytic dissociation"; test the skills of weighing on scales, using measuring utensils and chemical reagents, and making calculations using formulas.
You will be given 2 hours to complete this laboratory work.
In laboratory work, scales, weighing scales, measuring utensils (measuring cups and cylinders), and chemical reagents are used.
In this work, it is necessary to prepare a solution of a given concentration and make the necessary calculations.
Progress
1. Weigh a 10 g sample of salt (weigh to the nearest whole unit).
2. Calculate the mass of the solvent using the formula: m H2O = m solution – m substance. 100 g – 10 g = 90 g
3. Measure 90 ml of water into a measuring cylinder.
4. Pour a portion of salt into a glass, add water and stir with a glass rod.
5. Complete tasks to solve problems to determine the mass fraction of a dissolved substance, the mass of a substance, solution, solvent.
6. Write down the results of observations and calculations in a notebook and draw appropriate conclusions.
It is recommended to work in small groups of at least 4 people. Each group receives individual tasks and begins to implement them.
When preparing for laboratory work, students need to repeat the contents of the notebook on this topic, as well as Chapter 4 “Theory electrolytic dissociation"According to the textbook O.S. Gabrielyan, I.G. Ostroumov - Chemistry.
The criteria for the quality of laboratory work are:
1. Ability to use scales and measuring utensils.
2. Correctness of the calculations made.
3. Drawing up a report on the completion of the work.
4. Discipline during work.
Laboratory work No. 2
Subject"Classification of inorganic substances and their properties. Carrying out reactions that confirm the chemical properties of the main classes of chemical substances."The purpose of this laboratory work learn to apply knowledge about the properties of inorganic substances. Be able to carry out reactions between inorganic substances, obtain inorganic substances, draw conclusions, write reaction equations in molecular and ionic forms, draw up an electronic balance of redox reactions.
Progress
Using the necessary reagents, carry out the following chemical reactions characterizing the properties of acids, bases, metals, metal oxides and salts:
1) interaction of magnesium with hydrochloric acid;
2) interaction of copper (II) oxide with sulfuric acid;
3) obtaining copper (II) hydroxide;
4) interaction of copper (II) hydroxide with nitric acid;
5) qualitative reactions to:
a) barium ions;
b) iron ions (+2);
c) iron ions (+3);
6) the effect of indicators (litmus, methyl orange, phenolphthalein) on acids and alkalis.
For laboratory work, pallets for chemical reagents and equipment are used; stand with a set of test tubes. A set of chemical reagents: magnesium (powder or shavings), hydrochloric acid, copper (II) oxide, sulfuric acid, copper (II) sulfate solution, sodium hydroxide solution; nitric acid, barium chloride solution, iron (II) sulfate solution, iron (III) chloride solution, red blood salt solution, yellow blood salt solution.