Lesson - Practical work No. 4 (Grade 9)

Lesson type: lesson- practiceusing information and communication technologies.

Subject: Solution experimental tasks on the topic: "Oxygen subgroup".

Lesson objectives:

I . formation of UUD

1. Personal UUD - the possibility of self-determination in practical work on intellectual capabilities (the organizer takes a sheet, evaluating his abilities and capabilities).

2. Regulatory UUD - goal setting, planning and organization of activities, forecasting, control, correction, evaluation.

3. Cognitive UUD - research actions (application of knowledge in a specific situation, solving experimental problems, as a component of the education of logical thinking)

4 Communicative UUD - organization and planning of work in a group, the ability to agree and find a common solution, building interpersonal relationships.

II. Using knowledge of qualitative reactions to ions, learn by experience to recognize chemicals;

III. To develop the cognitive activity of students in the process of performing the experiment;

IV. Cultivate accuracy, respect for the use of chemical reagents;

V. To consolidate the skills of working with a virtual laboratory.

During the classes

Organizational moment.

Hello guys. Today we have guests at the lesson, these are chemistry teachers from schools in our district. Turn around and greet them. Amazing. Have a seat. I hope everyone has prepared notebooks, pens, pencils for the lesson. Then we start.

Motivation:: add a word to the phrase

CHEMICAL

Pay attention to the board. I wrote only one word "CHEMICAL", add words to make phrases (EXPERIMENTS, REACTIONS, PHENOMENA, PROCESSES, etc.)

Tell me, is there anything that can unite all these phrases? (Practical work).

Right. And today in the lesson we will do practical work with you. We work, as usual, in groups. Open your notebooks, write down the date and the topic of the work “Solving experimental problems on the topic “Oxygen subgroup”.

At home, you prepared for today's lesson, looked at the problems on page 146-147 of your textbooks and thought about the goal. How do you think it should sound?

apply the knowledge gained in the study of the topic "Oxygen Subgroup" in experimental problem solving;

to consolidate the skills of conducting a chemical experiment.

Okay, let's write down the purpose of the work in a notebook.

Is it necessary for the work to be successful and without consequences for health?

Comply with safety rules and group work rules.

We repeat the rules of T.B. (we repeat according to the table, where only pictures are left)

RULES OF WORK IN GROUPS:

Compliance with all TB rules

Keep quiet, don't disturb others, they work too

Speak your thoughts, do not criticize others

Know how to negotiate, find a common solution.

On the tables is a folder with instructions for doing the work. (20 minutes)

We distribute roles

A) organizer (works with an instruction card, figuring out what to do, gives instructions to the performer)

B) performer - practitioner (conducts reactions)

C) controller-analyst (analyzes observations and corrects the work of the organizer)

The first task (problem No. 4 on page 147) we will solve with you with the help of a virtual laboratory. From each group I invite one person here. Guys, quickly distribute the roles. Decided? Begin. I remind the guys in groups about compiling a reporting table.

Thank you. You can sit down and continue to work in your groups, but in other roles.

Conclusion : What conclusion did you draw from the results of the work? Let's correct it.

Guys, our lesson is coming to an end. What can you say about today's work?

- I did the best...

- I can commend myself for……

- I can praise my classmates…..

- I was surprised...

- In my opinion it was not possible….., because…….

- For the future, I will take into account……….

Okay, now

Everyone takes trays and notebooks to the teacher's demonstration table, tidies up the workplace

Final part.

Thank you all for your workyou will learn the results in the next lesson. At home, repeat the composition of the air and think about the next task.

HOME EXPERIENCE

From the proposed materials: 50 ml., 9% acetic acid, 1 tbsp.NaHCO 3 (c ode), 100 ml. H 2 O, 1 st. a spoonful of detergent, beetroot juice, salt dough or plasticine. offer instructions for conducting a chemical experiment, which can serve as a visual aid in a geography lesson in grade 6

Carry out reactions confirming the qualitative composition of sulfuric acid. Write reaction equations.

Place 1-2 zinc granules in a test tube and add about 1 ml of dilute sulfuric acid to it. What are you observing? Write a reaction equation and consider redox processes.

Pour the sodium sulfide solution into two test tubes. Pour chlorine water into one of them, and bromine water into the other. What are you observing? Explain your observations. Write the equations of the corresponding reactions in molecular and ionic forms.

Chlorine and bromine water are oxidizing agents, therefore, in both test tubes, sulfide will be oxidized to sulfur.

Solutions become colorless.

You are given three test tubes with solutions. Determine which of them contains hydrochloric acid, sulfuric acid and sodium hydroxide. Write the equations of the corresponding reactions in molecular and ionic forms.

Determine if table salt contains sulfates. Write the reaction equations in molecular and ionic forms.

Using characteristic reactions, establish whether the salt given to you is sulfate, iodide or chloride. Write the equations of the corresponding reactions in molecular and ionic forms.

Based on copper (II) oxide, get a solution of copper (II) sulfate and isolate crystalline copper sulfate from it. Write the equations of the corresponding reactions in molecular and ionic forms.

Sections: Chemistry

Lesson form: practical work.

Lesson objectives:

• Educational:

Repeat and consolidate practical skills in performing chemical experiments, handling reagents, observing safety rules;
- learn to select the reagents necessary for work, to assume the observed phenomena, to draw conclusions;
- consolidate skills in compiling equations of ion exchange reactions, compiling dissociation equations, complete and reduced ionic equations.

• Developing:
continue the development of self-education skills - work with a methodological guide, additional literature.

• Educational:

Continue the formation of worldview concepts about the knowability of nature, the cause-and-effect relationship between the composition, structure and properties of substances;
- students must be able to work carefully, consciously comply with established rules (for example, safety precautions).

Equipment: a graphic projector with code films, a solubility table, a TV set, a programmed methodological manual, tables for filling out a work report and reference tables ( Appendix 1), test tube racks, trays, waste bottles, hourglasses, indicators - phenolphthalein and litmus, solutions of barium chloride, iron (II) sulfate, sodium carbonate, sulfuric acid, silver nitrate, red blood salt, sodium hydroxide, calcium chloride, copper sulfate (II), calcium hydroxide, hydrochloric acid. To solve the problems of substance recognition, students are given solutions of sulfuric acid, calcium hydroxide and calcium chloride in numbered vials.

Lesson structure:

• Organizing time. 1 min.
• Motivation. 1 min.
• Repetition of methods for determining cations and anions in solutions. 2 minutes.
• Report on the procedure for performing experiments and evaluating work. 2 minutes.
• A reminder of the structure of the programmed methodological manual. 1 min.
• Performing tasks using a programmed methodological manual. 35 min.
• Summarizing. 3 min.

During the classes

Motivation. A whole science, analytical chemistry, is engaged in the recognition of substances, the proof of their composition. It employs more people than the chemical industry.

Repetition. Let's recall the methods for determining cations and anions in solutions (you can use the issued reference materials):

• flame staining (the only way to detect sodium). The teacher shows a video fragment;
• precipitation reactions (small and insoluble substances are formed - white or colored precipitates);
• color reactions - usually a change in the color of indicators in acidic and alkaline solutions;
• reactions with the release of gases, such as carbon dioxide. The teacher conducts demonstration experiments.

Work sequence.

You have to complete 4 experiments on your own. Each of the first three is given 7 minutes. If the time spent is greater, the third experiment can be omitted. Use an hourglass to control time. At the end of the lesson, you give the teacher the answer to the problem of substance recognition (experiment 4) in the form of two completed tables. At the end of the lesson, you get two grades: for completing the control experiment and for completing the entire work.

Sequence of work with programmed allowance(Table 1). You read the first task printed on the left page of the spread of the manual at the top, and write down on this page the missing word, the formulated answer, the reaction equation. On the left side of the right page spread, separated by a vertical line, the necessary explanations and drawings are provided to help arrive at the correct answer. After completing the task, turn the page and on the right side of the next spread, find the answer and compare what you wrote down with the correct one printed under the same number.

After receiving confirmation of the correctness of the answer, you can move on to the next task, which is printed at the top of the left page of the next spread and has a number one more than the previous one.

Please read the safety instructions before experimenting.

Safety regulations:

• Substances can not be taken by hand, check the taste and smell.
• Don't mix substances you don't know without your teacher's instructions.
• When performing experiments, use small doses of substances.
• Handle acids and alkalis with care.
• If solutions come into contact with hands or clothing, rinse immediately with plenty of water.
• Wash your hands with soap after work.
• Use only clean laboratory glassware.
• Do not pour out the remains of substances and do not pour them back into the vessel with pure substances.

I am familiar with the safety regulations (a) ………………… (signature)

Table 1

Programmed allowance

Left page spread of the manual	Right page spread of the manual
Exercise	Explanation for the task	Answer
Experience 1 Confirm the qualitative composition of barium chloride 1. In an aqueous solution, barium chloride dissociates into ions BaCl 2 \u003d Ba 2+ + 2Cl - Therefore, it is necessary to prove the presence of cations in the solution with the help of qualitative reactions ……. and anions……
2 . According to table 2 ( Appendix 1) select appropriate reagents The reagent for barium cations is ...... - anion, ...... Reactant for chloride - anions are cations ......		1 . Cl - (chloride - anions)
3 . To carry out the reaction, pour two samples of the initial solution with a volume of 0.5 ml each into two test tubes 4. Add a colorless transparent solution of sulfuric acid to the first test tube ...... containing sulfate - anions BaCl 2 + H 2 SO 4 \u003d BaSO 4 + 2HCl Ba 2+ + 2Cl - + 2H + + SO 4 2- = BaSO 4 + 2H + + 2Cl - Ba 2+ + SO 4 2- \u003d BaSO 4 Checking equations by the sum of coefficients: in the molecular equation…… in the full ionic equation…… in the reduced ionic equation……		2 . sulfate -, SO 4 2- silver, Ag+
5 . Add silver nitrate solution …… containing silver cations to the second tube ...... a precipitate is formed as a result of the reaction BaCl 2 + 2AgNO 3 \u003d Ba (NO 3) 2 + 2AgCl Ba 2+ + 2Cl - + 2Ag + + 2NO 3 - = Ba 2+ + 2NO 3 - + 2AgCl Ag + + Cl - = AgCl The sum of the coefficients: in the molecular equation…… in the full ionic equation…… in the reduced ionic equation……		4 .
Conclusion Using the precipitation reactions, we proved that the barium chloride solution contains cations …… and anions ……, thereby confirming the composition of the given salt		5 . white curdled
Experience 2 Confirm the qualitative composition of iron(II) sulfate FeSO 4 \u003d Fe 2+ + SO 4 2- Therefore, using qualitative reactions, it is necessary to prove the presence of cations …… and anions …… in the solution.
2 . According to tables 2 and 3 ( Appendix 1) select appropriate reagents The reagent for doubly charged iron cations is an alkali solution containing ...... - anions or a solution of red blood salt ...... Reactant for sulfate - anions are barium cations ......		1 . SO 4 2-, sulfate anions
3 . To carry out the reaction, pour into three test tubes three samples of the initial solution with a volume of 0.5 ml each 4. Add sodium hydroxide solution to the first tube A precipitate is formed ...... of color as a result of the reaction FeSO 4 + 2NaOH \u003d Na 2 SO 4 + Fe (OH) 2 Fe 2+ + SO 4 2- + 2Na + + 2OH - = 2Na + + SO 4 2- + …… Fe 2+ + 2OH - \u003d ... ...		2 . OH - , hydroxide -
5 . Add red blood salt solution K 3 to the second test tube. A precipitate is formed ...... of color as a result of the reaction 3FeSO 4 + 2K 3 \u003d 3K 2 SO 4 + Fe 3 2 3Fe 2+ + 3SO 4 2- + 6K + + 2 2- = 6K + + 3SO 4 2- + Fe 3 2 3Fe 2+ + 2 2- = Fe 3 2 The sums of the coefficients in the above equations are respectively ……, ……, …… (When performing control work, only one qualitative reaction is carried out for the ion to be determined)		4 . greenish
6 . Add the barium chloride solution to the third test tube…… A precipitate is formed ...... of color as a result of the reaction FeSO 4 + BaCl 2 \u003d BaSO 4 + FeCl 2 Fe 2+ + SO 4 2- + Ba 2+ + 2Cl - \u003d BaSO 4 + Fe 2+ + 2Cl - …… + …… = …… The sums of the coefficients in the above equations, respectively ……, ……, ……		5 .
Conclusion Using the precipitation reactions, we proved that the composition of iron (II) sulfate contains the cation ...... and the anion ......		6 . Ba 2+ + SO 4 2- \u003d BaSO 4 v
Experience 3 Confirm the qualitative composition of sodium carbonate 1. In an aqueous solution, this salt dissociates into ions Na 2 CO 3 \u003d ... ... + ... ... Therefore, it is necessary, using qualitative reactions, to prove the presence in the solution of cations …… and CO 3 2- (…… - anions)
2 . According to tables 1 and 2 ( Appendix 1) select appropriate qualitative reactions Sodium is determined by the coloration of a colorless flame of a gas burner (experiment is not carried out during the work). Reactant for carbonate - anions are cations ...... and acid solutions containing cations ......		1 . Na + and (carbonate anions)
3 . To carry out qualitative reactions for carbonate - ions, pour samples of the initial solution into two test tubes with a volume of 0.5 ml each 4. Add to the first tube a solution of calcium chloride …… (or calcium hydroxide ……) containing cations …… A white precipitate is formed, which dissolves when hydrochloric acid is added ...... (in this case, bubbles of a transparent colorless gas appear in the test tube) When a precipitate is formed, the reaction Na 2 CO 3 + CaCl 2 \u003d 2NaCl + CaCO 3 2Na + + CO 3 2- + Ca 2+ + 2Cl - \u003d 2Na + + 2Cl - + CaCO 3 …… + …… = …… The sum of the coefficients in the equations, respectively ……, ……, …….		2 .
5 . Add the hydrochloric acid solution to the second test tube…… An odorless gas is released, causing the lime water to become cloudy (proof of CO 2 emission: moisten the slide with calcium hydroxide solution and hold it over the test tube until it becomes cloudy) Na 2 CO 3 + 2HCl \u003d 2NaCl + CO 2 + H 2 O 2Na + + CO 3 2- + 2H + + 2Cl - \u003d 2Na + + 2Cl - + CO 2 + H 2 O 2H + + CO 3 2- \u003d CO 2 + H 2 O The sums of coefficients ……, ……, ……		4 . CaCl 2 or Ca(OH) 2 Ca 2+ (calcium) Ca 2+ + CO 3 2- \u003d CaCO 3 v
Conclusion Using the precipitation reaction and the gas evolution reaction, we proved that the sodium carbonate solution contains …… – anions CO 3 2-		5.
Experience 4.(Task for the recognition of substances) Recognize with the help of characteristic reactions solutions of sulfuric acid, calcium hydroxide and calcium chloride, which are in three numbered vials (To recognize means to determine by experience what substance is in each of the vials) 1. Substances in the issued solutions belong to the classes ……, ….… and …… respectively, and are (strong / weak) …… electrolytes In aqueous solution, these substances dissociate into ions H 2 SO 4 \u003d 2H + + SO 4 2- Ca (OH) 2 \u003d Ca 2+ + 2OH - CaCl 2 \u003d Ca 2+ + 2Cl - Therefore, it is necessary, using qualitative reactions, to prove the presence in the solution of the following cations: H +, Ca 2+, and anions: SO 4 2-, OH -, Cl -
2 . According to tables 2 and 3 ( Appendix 1) select the appropriate reagents Detected ion: Reagent: hydrogen cation H + …… calcium cation Ca 2+ …… hydroxide - OH anion - …… sulfate - anion SO 4 2- ... ... chloride - anion Cl - ......		1 . base - (alkali) strong
3 . To carry out the reactions, pour 0.5 ml of each of the three samples into three clean test tubes Using the solubility table, select the sequence in which you add the reagents so that you can only precipitate in one test tube in one experiment: 5…… (experience may not be)		2 . CO 3 2-, Na 2 CO 3 litmus or phenolphthalein
4 . Add Reagent #1 to three sample tubes. Record observations in worksheet 2 5. Add Reagent #2 to three new sample tubes. Record the observations in Table 2. If using reagents 1 and 2 you have established the qualitative composition of one of the samples, you can write it in the corresponding line at the bottom of the table. This sample is not tested further. 6. Add Reagent #3 to the samples of the remaining samples. Write down the observations By analogy, continue working with reagents No. 4 and No. 5		3 . 1 or 2 - BaCl 2 2 or 1 - litmus 3, 4, 5 - your options
7 . Fill in tables 2 and 3 and submit for verification

Homework. In addition to the abbreviated ionic equations in Worksheet 4, write the molecular and full ionic equations in your notebook.

table 2

The results of solving the recognition problem

Table 3

Report on the completion of the recognition task (experiment 4)

Practical work No. 4
Experimental tasks on the topic "Oxygen subgroup"

Task 1

Carry out reactions confirming the qualitative composition of sulfuric acid. Write reaction equations.

Task 2

Place 1-2 zinc granules in a test tube and add about 1 ml of dilute sulfuric acid to it. What are you observing? Write a reaction equation and consider redox processes.

Task 3

Pour 1-2 ml of sodium sulfide solution into two test tubes. Pour the same volume of chlorine water into one of them, and bromine water into the other. What are you observing? Explain your observations. Write the equations of the corresponding reactions in molecular and ionic form.

Task 4

You are given three test tubes with solutions. Determine which of them contains hydrochloric acid, sulfuric acid and sodium hydroxide. Write the equations of the corresponding reactions in molecular and ionic form.

Task 5

Determine if table salt contains sulfates. Write the reaction equations in molecular and ionic form.

Task 6

Using characteristic reactions, establish whether the salt given to you is sulfate, iodide or chloride. Write the equations of the corresponding reactions in molecular and ionic form.

Task 7

Based on copper (II) oxide, get a solution of copper (II) sulfate and isolate crystalline copper sulfate from it. Write the equations of the corresponding reactions in molecular and ionic form.

Task 8

You are given three test tubes with solutions of sulfate, sulfite and sodium sulfide. Determine, using only one reagent, in which test tube each of the substances is located. Write the equations of the corresponding reactions in molecular and ionic form.

Practical work No. 5
Experimental tasks on the topic "Subgroups of nitrogen and carbon"

Task 1

Carry out reactions that can be used to prove that the substance given to you in closed vessels is:

a) ammonium chloride;
b) sodium carbonate;
c) ammonium nitrate;
d) ammonia;
e) calcium carbonate;
e) sodium silicate.

Task 2

Prove empirically that ammonium sulfate and ammonium nitrate should not be mixed with lime before applying these fertilizers to the soil, and explain why. Write reaction equations.

Task 3

Prove experimentally that:

Write the equations of the reactions carried out in molecular and ionic form.

Task 4

Get ammonia from the following salts:

a) ammonium chloride;
b) ammonium sulfate;
c) ammonium nitrate.

Write the equations of the reactions carried out in molecular and ionic form.

Task 5

Carry out reactions that are expressed by abbreviated ionic equations:

Write the equations of the reactions carried out in molecular and ionic form.

In four test tubes you are given crystalline substances: sodium sulfate, zinc chloride, potassium carbonate, sodium silicate. Determine in which test tube each of the substances is located. Write the reaction equations in molecular and ionic form.

Practical work No. 6
Receiving, collecting and recognizing gases

Option 1

Experience 1.
Obtaining, collecting and recognizing hydrogen

Assemble the device for obtaining gases and check it for leaks. Put 1-2 zinc granules into a test tube and add 1-2 ml of hydrochloric acid to it. Close the test tube with a stopper with a gas outlet tube (see Fig. 76) and put another test tube on the tip of the tube. Wait some time for the test tube to fill with the evolved gas.

Remove the test tube from the gas outlet tube and, without turning it over, slightly tilting it, bring the hole to the burning spirit lamp. If there is pure hydrogen in the test tube, then a dull pop will be heard, if a "barking" sound - hydrogen is collected in a mixture with air, that is, "explosive gas" is collected in the test tube.

Questions and tasks:

1. What happens when zinc reacts with hydrochloric acid? Make an equation for the reaction and give its characteristics according to all the studied signs of the classification of chemical reactions.
2. Describe the physical properties of hydrogen that are directly observed during the experiment.
3. Describe how hydrogen can be recognized.

Experience 2.
Obtaining, collecting and recognizing ammonia

Assemble the device as shown in Figure 168 and check for leaks.

Rice. 168.
Ammonia production and collection by air displacement

Pour ammonium chloride and calcium hydroxide in a porcelain cup with a volume of one spoon each to burn substances. Stir the mixture with a glass rod and pour into a dry test tube. Close it with a stopper and fix it in the leg of the tripod (pay attention to the inclination of the test tube relative to the hole!). Put a dry test tube on the gas outlet tube to collect ammonia.

First, heat the entire test tube with a mixture of ammonium chloride and calcium hydroxide with 2-3 flame movements, and then heat only in the place where the mixture is located.

To detect ammonia, place a wet phenolphthalein paper upside down in a test tube.

Stop heating the mixture. Remove the test tube containing ammonia from the gas outlet tube. Immediately close the end of the gas outlet tube with a piece of wet cotton wool.

Immediately close the opening of the removed tube with your thumb, immerse the tube with the opening down in a vessel of water, and free the opening of the tube. What are you observing? Why did the water rise in the test tube? Close the opening of the tube under water with your finger and remove it from the vessel. Invert the tube and add 2-3 drops of phenolphthalein solution to it. What are you watching?

Carry out a similar reaction between solutions of alkali and ammonium salt when heated. Bring a wet indicator paper to the opening of the test tube. What are you watching?

Questions and tasks:

1. What happens when ammonium chloride and calcium hydroxide react? Make an equation for the reaction and give its characteristics according to all the studied signs of the classification of chemical reactions.
2. Describe the physical properties of ammonia that are directly observed in the experiment.
3. Describe at least two ways to recognize ammonia.

Option 2

Experience 1.
Obtaining, collecting and recognizing oxygen

Assemble the instrument as shown in Figure 109 and check for leaks. Fill the test tube approximately 1/4 of the volume with potassium permanganate KMnO 4, place a loose ball of cotton wool at the opening of the test tube. Close the test tube with a stopper with a gas outlet tube. Attach the test tube to the leg of the stand so that the end of the vent tube reaches almost to the bottom of the oxygen collection vessel.

First, heat the entire test tube with KMnO 4 with 2-3 flame movements, and then heat only in the place where the substance is located.

Check the presence of oxygen in the vessel with a smoldering splinter.

Questions and tasks:

1. What happens when potassium permanganate is heated? Make an equation for the reaction and give its characteristics according to all the studied signs of the classification of chemical reactions.
2. Consider the recorded reaction in terms of redox processes.
3. Describe the physical properties of oxygen directly observed in the experiment.
4. Describe how you recognized oxygen.

Experience 2.
Obtaining, collecting and recognizing carbon monoxide (IV)

Place a few pieces of chalk or marble in a test tube and add 1-2 ml of dilute hydrochloric acid. Quickly close the test tube with a stopper with a gas outlet tube. Dip the end of the tube into another test tube with 2-3 ml of lime water.

Watch for a few minutes as gas bubbles pass through the lime water.

Questions and tasks:

1. What happens when chalk or marble reacts with hydrochloric acid? Make an equation for the reaction and give its characteristics according to all the studied signs of the classification of chemical reactions.
2. Consider the reaction carried out in the light of the theory of electrolytic dissociation.
3. Describe the physical properties of carbon monoxide (IV) directly observed in the experiment.
4. Describe how you recognized carbon monoxide (IV).