Practical work No. 1
Option #1
Goal of the work: Solution of experimental problems consisting of a chain of transformations.
Equipment: Rack with test tubes.
Reagents: Magnesium sulfate MgSO 4, alkali NaOH, barium chloride BaCl 2, sulfuric acid H2SO4
MgSO 4 – MgCl 2 – Mg(OH) 2 - MgSO 4
| Reaction equations | Observations |
|
| MgSO4+ Mg 2+ + SO 4 2- + | ||
| MgCl2+ Mg 2+ + 2Cl - + | ||
| Mg(OH)2+ |
Conclusion:
Practical work No. 1
Carrying out a chain of chemical transformations of metals
Option 2
Safety briefing.
Purpose of work s: Solving experimental problems consisting of a chain of transformations.
Equipment: Rack with test tubes, alcohol lamp, matches, test tube holder
Reagents: Copper sulfate CuSO 4, alkali NaOH, sulfuric acid H 2 SO 4
CuSO 4 –Cu(OH) 2 – CuO – Cu SO 4
| Reaction equations | Observations |
|
| CuSO4+ | ||
| Cu(OH)2 | ||
| CuO+ |
Conclusion:
"Practical work No. 2"
Practical work No. 2
Safety briefing.
Goal of the work
Equipment: Rack with test tubes.
Reagents:
Option 1
Exercise 1.
| Reaction equations | Observations |
|
| AlCl 3 + NaOH = | ||
| NaOH + AlCl 3 = |
Conclusion:
Task 2
| Reaction equations | Observations |
|
| Al (OH) 3 + HCl = | ||
| Al (OH) 3 + NaOH = |
Conclusion:
Task 3.
| Reaction equations | Observations |
|
| CaCl2+ | ||
| CaCl2+ |
Conclusion:
Practical work No. 2
Preparation and properties of metal compounds
Safety briefing.
Goal of the work: Experimentally prove the amphotericity of aluminum.
Equipment: Rack with test tubes.
Reagents.
Option 2
Exercise 1.: AlCl 3, NaOH, HCl, FeSO 4, BaCl 2, K 3.
| Reaction equations | Observations |
|
| Determine whether the result of the reaction depends on the order in which the reagents are combined. | ||
| NaOH + AlCl 3 = |
Conclusion:
Task 2 AlCl 3 + NaOH =
| Reaction equations | Observations |
|
| . Study of the properties of Al (OH) 3 obtained. | ||
| Al (OH) 3 + NaOH = |
Conclusion:
Task 3. Al(OH)3 + HCl =
| Reaction equations | Observations |
|
| Prove the quality composition of FeSO 4 | ||
| FeSO 4 + K 3 = |
Conclusion:
FeSO4+
View document contents
"Practical work No. 3"
Safety briefing.
Goal of the work
Equipment Practical work No. 3
Reagents: rack with test tubes.
Option #1
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
Progress Problem 1
. Determine which test tube contains each of the substances: NaOH, K 2 CO 3, BaCl 2.
Conclusion:
We observe:...
2.Use indicator paper to identify the test tube containing the alkali:
Test tube No. 1 - color: ...
No. 2- color: ...
Conclusion: No. 3- color: ...
test tube No. ... contains alkali.
(.).
Conclusion: 3.Pour into preparation No. ... H 2 SO 4
in test tube No. ... is ........ Task 2.
Obtain NaAlO 2 from Al.
1.Add excess alkali to the test tube with aluminum powder:.)
| (Observation, reaction equations, conclusions | What am I doing? | What am I observing? |
"Practical work No. 3"
Reaction equations or conclusions
Safety briefing.
Goal of the work Solving experimental problems on recognizing and obtaining substances
Equipment Practical work No. 3
Reagents: learn to experimentally identify and obtain substances.
: Na 2 SO 4, CaCO 3, KCl, BaCl 2, HCl, iron filings.
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
Progress . Determine which test tube contains each of the substances: Na 2 SO 4, CaCO 3, KCl.
1. Pour H 2 O into each test tube.
We observe the dissolution of substances:...
Conclusion: in test tube No. ... there is ........
2.Add HCl to the test tube:
(Observation, reaction equations.)
Conclusion: in test tube No. ... there is ........
3.Pour into preparation No. ... BaCl 2
(Observation, reaction equations, conclusions.)
Conclusion: in test tube No. ... there is ........
Problem 2 . GetFeCl 2 fromFe .
Add HCl to the test tube with iron filings:
(Observation, reaction equations, conclusions.)
Present the results in table form:
| (Observation, reaction equations, conclusions | What am I doing? | What am I observing? |
FeSO4+
"Practical work No. 4"
Practical work No. 4
Solving experimental problems on the topic “Oxygen subgroup”
Safety briefing.
Goal of the work: consolidate theoretical knowledge of qualitative reactions in practice.
Equipment: stand with test tubes, evaporation cup, alcohol lamp.
Reagents: phenolphthalein indicator, AgNO 3, BaCl 2, NaOH, H 2 SO 4, HCl, NaCl, KI, ZnSO 4.
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
Exercise 1. Determine which test tube contains each of the substances: NaOH, H 2 SO 4, HCl (p. 147 No. 4).
Conclusion: test tube No.... is located.....
Task2. Give qualitative reactions for substances: NaCl, KI, ZnSO 4 .(page 147 No. 6).
Conclusion: high-quality reagents for ions ..... are ......
Task 3. Obtain from CuO, CuSO 4, and CuSO 4 ∙5H 2 O. (page 147 No. 7).
Conclusion:
Present the results in table form:
| (Observation, reaction equations, conclusions | What am I doing? | What am I observing? |
FeSO4+
"Practical work No. 5"
Practical work No. 5
Safety briefing.
Goal of the work
Equipment Practical work No. 3
Reagents: NH 4 Cl, NaOH, HCl, CaCO 3, AgNO 3, BaCl 2, Na 2 SO 4, K 2 CO 3, Na 2 SiO 3
Option 1
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
Exercise 1. Prove experimentally that the composition of ammonium chloride includes Cl - AndN.H. 4 +
Conclusion:
Task 2 Na 2 SO 4 , K 2 CO 3 , Na 2 SiO 3 . Determine what substance is in each test tube. Give the reaction equations in molecular, full and abbreviated ionic form.
Conclusion:
Present the results in table form:
| (Observation, reaction equations, conclusions | What am I doing? | What am I observing? |
Practical work No. 5
Solving experimental problems on the topic “Nitrogen and carbon subgroup”
Safety briefing.
Goal of the work: learn to experimentally determine the qualitative composition of a substance.
Equipment Practical work No. 3
Reagents: NH 4 Cl, NaOH, HCl, CaCO 3, AgNO 3, BaCl 2, ZnCl 2, K 2 CO 3, Na 2 SiO 3
Option 2.
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
Exercise 1. Prove experimentally that the composition of ammonium sulfate includes SO 4 2- AndN.H. 4 + ions. Give the reaction equations in molecular, full and abbreviated ionic form.
Conclusion:
Task 2. The test tubes contain crystalline substances: ZnCl 2 , K 2 CO 3 , Na 2 SiO 3 , Determine what substance is in each test tube. Give the reaction equations in molecular, total and abbreviated ionic form.
Conclusion:
Present the results in table form:
| (Observation, reaction equations, conclusions | What am I doing? | What am I observing? |
FeSO4+
"Practical work No. 6"
Practical work No. 6
Safety briefing.
Goal of the work: learn by experience to receive, collect and recognize carbon dioxide
Equipment: stand with test tubes, splinter, matches
Reagents: HCl, CaCO 3.
Option 1.
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
1. Conduct an experiment in obtaining CO 2
Observations:
2. Create an equation for the reaction to obtain CO 2 in molecular, full and reduced ionic form.
4. Bring observations to the recognition of CO 2
| (Observation, reaction equations, conclusions | What am I doing? | Reaction equations and conclusions |
Conclusion:
Practical work No. 6
Receiving, collecting and recognizing gases
Safety briefing.
Goal of the work: learn to experimentally obtain, collect and recognize hydrogen.
Equipment: stand with test tubes, matches.
Reagents: HCl, zinc
Option 2.
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
1. Conduct an experiment in obtaining H 2
Observations
2. Draw up an equation for the reaction to produce H 2 in molecular, full and reduced ionic form.
3. Characterize the reaction (reversibility, endothermicity, compounds - decomposition, etc.)
4. Bring observations to recognize H 2
Present the result in the form of a table:
| (Observation, reaction equations, conclusions | What am I doing? | Reaction equations and conclusions |
Conclusion:
Practical work No. 6
Receiving, collecting and recognizing gases
Safety briefing.
Goal of the work: learn to experimentally receive, collect and recognize oxygen.
Equipment: stand with test tubes, matches, splinter.
Reagents: KMPO 4
Option 3.
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
1. Conduct an experiment in obtaining O 2
Observations
2. Create an equation for the reaction to obtain O 2 in molecular, full and reduced ionic form.
3. Characterize the reaction (reversibility, endothermicity, compounds - decomposition, etc.)
4. Bring observations to the recognition of O 2
Present the result in the form of a table:
| (Observation, reaction equations, conclusions | What am I doing? | Reaction equations and conclusions |
Conclusion:
FeSO4+
"Practice 2 changed"
Practical work No. 2
Preparation and properties of metal compounds
Safety briefing.
Goal of the work: Experimentally prove the amphotericity of aluminum. Prove the qualitative composition of CaCO 3.
Equipment: Rack with test tubes.
Reagents: AlCl 3, NaOH, HCl, CaCL 2, AgNO 3, Na 2 CO 3
Option 1
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
Exercise 1.: AlCl 3, NaOH, HCl, FeSO 4, BaCl 2, K 3.
b) add AlCl 3 to NaOH
Task 2 AlCl 3 + NaOH =
b) Al (OH) 3 + NaOH =
Task 3. Prove the quality composition of CaCL 2
Carry out the experiment: a) CaCl 2 + ……
b) CaCl 2 + ……..
draw a conclusion and put the results in the table:
Practical work No. 2
Preparation and properties of metal compounds
Safety briefing.
Goal of the work
Equipment: Rack with test tubes.
Reagents: AlCl 3, NaOH, HCl, FeSO 4, BaCl 2, K 3.
Option 2
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
Exercise 1.: AlCl 3, NaOH, HCl, FeSO 4, BaCl 2, K 3.
Carry out the experiment: a) add NaOH to AlCl 3
b) add AlCl 3 to NaOH
Draw a conclusion and put the results in the table:
Task 2 AlCl 3 + NaOH =
Carry out the experiment: a) Al (OH) 3 + HCl =
b) Al (OH) 3 + NaOH =
draw a conclusion and put the results in the table:
Task 3. Al(OH)3 + HCl =
Carry out the experiment: a) FeSO 4 + K 3 =
b) FeSO 4 + ……..
draw a conclusion and put the results in the table:
Do general conclusion about the work done.
Practical work No. 1
on this topic: "»
Goal of the work:
Equipment:
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
1. Tripod setup
2. Alcohol lamp device
3.Dishes
4.Filtration
3. put into a funnel;
"8th grade"
Practical work No. 1
on this topic: "Safety rules when working in a chemical laboratory. Handling techniques for laboratory equipment and heating devices»
Safety briefing.
Goal of the work: Familiarize yourself with the structure and basic techniques for handling laboratory equipment.
Equipment: Tripod, alcohol lamp, laboratory glassware.
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
1. Tripod setup(draw a tripod, label its components)
2. Alcohol lamp device(draw a spirit lamp, label its components)
3.Dishes(draw test tubes, flasks, beakers)
4.Filtration
1. prepare filter paper;
2. moisten the filter paper;
3. put into a funnel;
4. liquid is poured onto a glass rod, pointing it at the wall of the funnel;
5. The filtrate flows down the wall of the glass, and not into the center, so as not to splash out.
Find in the text definitions of filtrate, sediment and filtration process.
Practical work No. 2
on this topic: « Observations of changes occurring with a burning candle and their description»
Target: observe physical and chemical phenomena when a candle burns.
Equipment: glass slide, candle, matches, dry test tube, holder.
Glass is a brittle material with low impact resistance and low bending strength. It is strictly forbidden to use cookware that has cracks or broken edges.
The test tube is fixed in the holder so that there is a distance of 1 - 1.5 cm from the neck of the test tube to the holder.
The glass slide is first heated completely and then brought into the area of the dark cone of the burning candle.
First aid for burns:
First aid for cuts:
Experience No. 1. Physical phenomena when a candle burns.
Light a candle. You will see how the paraffin begins to melt near the wick, forming a round puddle. What process is taking place here?
Experience No. 2. Detection of combustion products in a flame.
Take a glass slide, secure it in the holder ( t/b), bring a burning candle into the dark cone area and hold for 3–5 s. Quickly lift the glass and look at the bottom plane. Explain what appeared there.
Place the dry test tube in the holder ( t/b), turn it upside down and hold it over the flame until it fogs up. Explain the observed phenomenon.
Practical work No. 3
on this topic: "Soil and water analysis»
Target: determine the composition of the soil, learn how to filter and evaporate liquid.
Equipment: two test tubes, a funnel, a paper filter, a glass rod, a glass slide, an alcohol lamp, a glass cylinder with water, a stopper, and universal indicator paper.
Safety instructions:
The slide is carefully secured in the holder at one of its edges. It is taken into account that glass is a fragile material and can crack if you press hard on it.
In the process of evaporating water from the soil extract, the entire glass slide is first heated, and then a drop of liquid on it.
First aid for cuts:
a) first of all, it is necessary to stop the bleeding (pressure bandage, clamping of the vessel);
b) if the wound is dirty, the dirt is removed only around it, but in no case from the deep layers of the wound. The skin around the wound is disinfected with iodine tincture or a solution of brilliant green;
c) after treatment, the wound is covered with a sterile napkin so as to cover the edges of the wound, and bandaged tightly with a regular bandage;
d) after receiving first aid, go to the first aid station.
First aid for burns:
A first-degree burn is treated with ethyl alcohol, then, to relieve pain, with glycerin and a dry sterile bandage is applied. In all other cases, apply a sterile bandage after cooling the burn site and go to the medical center.
Experience No. 1. Mechanical soil analysis.
Soil is placed in a test tube. Pour water into it, the volume of which should be 3 times the volume of the soil. Close the tube with a stopper and shake thoroughly for 1 - 2 minutes. Observe the settlement of soil particles and the structure of sediments. Describe and explain your observations.
Experience No. 2. Preparation of soil solution and experiments with it.
Prepare a paper filter, insert it into a clean test tube 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 slide using a glass rod and hold it over the flame of an alcohol lamp ( t/b) until the water evaporates. What are you observing? Explain.
Take universal indicator paper and apply the soil solution to it with a glass rod. Draw a conclusion based on the results of your observations.
Practical work No. 4
on this topic: "Preparation of a sugar solution and determination of its mass fraction in the solution»
Safety briefing
Target: learn to weigh on laboratory scales, determine the volume of liquid using a graduated cylinder, prepare a solution with a certain mass fraction substances.
Equipment and reagents: beaker, stirring rod, measuring cylinder, laboratory scales, weighing scales; sugar, water.
Work order
Calculate the mass of sugar and mass of water required to prepare the solution you need using the formulas:
m (substances) =m (solution) ω(substance)
m
(H
2
O
) =
m
(solution) -m
(substances)
Provide calculations in the report on practical work.
Determine the volume of water corresponding to the calculated mass using the formula: V=m
· ρ.
Remember that for water ρ = 1 g/ml.
Provide the calculation in the report on practical work.
Using a graduated cylinder, measure the calculated volume of water. Pour the water into a beaker.
Weigh the calculated mass of sugar on a laboratory scale. Pour sugar into a glass of water.
Stir the contents of the beaker until the sugar is completely dissolved.
Draw a conclusion about what is needed to prepare a solution with a certain mass fraction of solute.
Practical work No. 5
on this topic: "Signs of chemical reactions»
Target: consider examples of chemical reactions and identify their signs.
Equipment: test tubes, copper wire, alcohol lamp, copper (II) oxide, sulfuric acid solution, marble, hydrochloric acid solution, solutions of iron (III) chloride and potassium thiocyanate, solutions of sodium sulfate and barium chloride.
Safety instructions:
If you light a spirit lamp immediately after removing the cap, the film of alcohol on the neck of the spirit lamp lights up exactly at the place where the cap is adjacent to the neck. The flame penetrates under the disk with the tube, and the alcohol vapor inside the tank ignites. An explosion may occur and the disc may be ejected along with the wick. To avoid this, lift the wick disk for a few seconds to release the vapors. If the vapors should ignite, quickly set the items aside (notebook practical work) and call the teacher.
A lit alcohol lamp cannot be moved from place to place, nor can one light one alcohol lamp directly from another. Use matches to light the alcohol lamp.
There is only one way to extinguish an alcohol lamp - cover the flame of the wick with a cap. The cap should always be at hand.
Acids are caustic substances. They destroy and irritate the skin and mucous membranes.
The acid must be poured so that when the bottle is tilted, the label is on top to avoid damage.
Copper compounds in the form of dust, if they come into contact with the skin, especially in places of microtrauma, can cause irritation and lead to mild allergies.
It is necessary to work with barium compounds in such a way as to prevent them from entering the mouth, as they are toxic. To obtain severe poisoning, a dose weighing less than 0.5 g is sufficient. After completing work, wash your hands thoroughly with soap and running water.
First aid for cuts:
a) first of all, it is necessary to stop the bleeding (pressure bandage, clamping of the vessel);
b) if the wound is dirty, the dirt is removed only around it, but in no case from the deep layers of the wound. The skin around the wound is disinfected with iodine tincture or a solution of brilliant green;
c) after treatment, the wound is covered with a sterile napkin so as to cover the edges of the wound, and bandaged tightly with a regular bandage;
d) after receiving first aid, go to the first aid station.
First aid for burns:
A first-degree burn is treated with ethyl alcohol, then, to relieve pain, with glycerin and a dry sterile bandage is applied. In all other cases, apply a sterile bandage after cooling the burn site and go to the medical center.
First aid if acid gets on your hands:
Shake off drops of acid that get on the skin and rinse thoroughly with plenty of water, and then treat the affected surface with a 2% solution of baking soda.
First aid for barium salt poisoning:
Rinse the stomach with a 1% solution of sodium sulfate or magnesium sulfate.
Experiment No. 1 Calcination of copper wire.
Light the alcohol lamp. Take a copper wire with crucible tongs and bring it into the flame. After a while, remove the wire from the flame. What are you observing?
Experiment No. 2 Interaction of sodium carbonate with hydrochloric acid.
Place some sodium carbonate in a small beaker. Pour enough hydrochloric acid into a beaker to cover the sodium carbonate. What are you observing?
Light a splinter and bring it into the glass. What are you observing?
Write a report by filling out the table.
Experiment No. 3 Interaction of ammonium chloride with sodium hydroxide.
Place some ammonium chloride in the test tube. Pour enough sodium hydroxide solution into the test tube to cover the ammonium chloride. Shake thoroughly. Carefully smell the contents of the tube.
Write a report by filling out the table.
Experiment No. 4 Interaction of copper sulfate ( II ) with sodium hydroxide.
Pour 2 ml of sodium hydroxide solution into a test tube, and then add 2-3 drops of copper (II) sulfate to it. What are you observing?
Write a report by filling out the table.
Experiment No. 5 Interaction of copper hydroxide ( II ) with hydrochloric acid.
Add a little hydrochloric acid solution to copper(II) hydroxide. Shake gently. What are you observing?
Write a report by filling out the table.
Experiment No. 6 Burning alcohol
Pour 2 ml into a cup ethyl alcohol. Light it carefully. What are you observing? Write a report by filling out the table.
Experiment No. 7 Malachite decomposition
Pour a small amount of malachite into the test tube. Heat it in the flame of an alcohol lamp. What are you observing?
Write a report by filling out the table.
| What they were doing | Observations | (sign chemical reaction) |
Practical work No. 6
on this topic: "Properties of acids, bases, oxides and salts»
Target: carry out in practice reactions that characterize the properties of acids, bases, oxides and salts.
Equipment and reagents: rack with test tubes; sulfuric acid, phosphoric acid, zinc, iron, copper(II) oxide, sodium hydroxide, silver nitrate, barium chloride, sodium carbonate, sodium phosphate, copper(II) chloride, phenolphthalein.
Safety instructions:
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
| What they were doing | |
| Experience 1 |
|
| Experience 2 |
|
Work order
Experience 1. Carry out reactions that characterize the properties of a sulfuric acid solution:
a) acid + metal = salt + H 2
b) acid + basic oxide = salt + H 2 O
c) acid + base = salt + H 2 O
d) acid + salt = salt + acid
Experience 2. Carry out reactions characterizing the properties of copper (II) chloride:
a) salt + metal = salt + metal
b) salt + alkali = base ↓ + salt
c) salt + acid = salt + acid
d) salt + salt = salt + salt↓
Write down equations for the reactions performed in molecular and ionic form.
Practical work No. 7
on this topic: "Solving experimental problems»
Target: carry out the assigned tasks experimentally.
Equipment and reagents: rack with test tubes; copper(II) sulfate, sodium hydroxide, barium chloride, sodium sulfate, magnesium sulfate, sodium carbonate, hydrochloric acid, phenolphthalein.
Safety briefing
: NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder.
| What they were doing | Observations and equations of chemical reactions | Conclusion about the type of chemical reaction |
| Experience 1. |
||
| Experience 2. |
||
Work order
Experience 1. Carry out the reactions whose schemes are given:
a) Ba 2+ + SO 4 2- = BaSO 4
b) CO 3 2- + 2H + = H 2 O + CO 2
c) OH - + H + = H 2 O
In the table, write down the observations and reaction equations in full and abbreviated molecular and ionic form.
Experience 2. Using the solutions on the table, you will get:
a) copper(II) hydroxide
b) magnesium carbonate
Record your observations in the table. Write reaction equations in molecular, full and reduced ionic form.
FeSO4+
"9th grade"
Practical work No. 1
on this topic: "Carrying out a chain of chemical transformations»
Safety briefing.
Goal of the work: Solution of experimental problems consisting of a chain of transformations.
Equipment: Rack with test tubes.
Reagents (1st century): Magnesium sulfate MgSO 4, alkali NaOH, barium chloride BaCl 2.
Reagents (2v.): Copper sulfate CuSO 4, alkali NaOH, hydrochloric acid HCl, Fe (paper clip).
Option 1: MgSO 4 – MgCl 2 – Mg (OH) 2 - MgSO 4
| Reaction equations | ||
| MgSO4+ Mg 2+ + SO 4 2- + | ||
| MgCl2+ Mg 2+ + 2Cl - + | ||
| Mg(OH)2+ |
Conclusion:
Option 2: CuSO 4 –Cu (OH) 2 – CuO – Cu
| Reaction equations | ||
| CuSO4+ | ||
| Cu(OH)2 | ||
| CuO+ |
Conclusion:
Practical work No. 2
Description of material: The development of the entire practical course in chemistry in grade 9 is presented (Chemistry course program for grades 8-9 educational institutions. Authors: N.E. Kuznetsova, I.M. Titova, N.N. Gara). Samples of the design of practical work with possible answers from students, instruction cards for practical work are given. Each practical work is accompanied by safety rules. Proposed student responses are in italics.
List of used literature:
1. Textbook: Kuznetsova N.E., Titova I.M., Gara N.N.; edited by N. E. Kuznetsova. Chemistry. - M.: Ventana - Graf, 2011.
2. Marshanova G.L. Safety precautions in the school chemistry laboratory. Collection of instructions and recommendations. - M.: Arkti, 2002.
3. Gara N.N., Zueva M.V. In a chemical laboratory. Workbook for 9th grade students of general education institutions. - M.: Ventana - Graf, 2007.
Picture 1
Figure 2
.jpg)
Figure 3
.jpg)
This application contains instructions for practical work for 9th grade students.
“Practical work No. 1 - 9th grade”
| Practical work No. 1 Goal of the work: Experimentally prove the amphotericity of aluminum. Prove the qualitative composition of CaCO 3. Equipment: Rack with test tubes. Reagents: Option 1 Exercise 1.
Conclusion: Task 2
Conclusion: Task 3. Prove the quality composition of CaCL 2
Conclusion: | Practical work No. 1 Preparation of metal compounds and study of their properties Safety briefing. Goal of the work: Experimentally prove the amphotericity of aluminum. Prove the qualitative composition of FeSO 4. Equipment: Rack with test tubes. Reagents: AlCl 3, NaOH, HCl, FeSO 4, BaCl 2, K 3. Option 2 Exercise 1.: AlCl 3, NaOH, HCl, FeSO 4, BaCl 2, K 3.
Conclusion: Task 2. Study of the properties of obtained Al (OH)3.
Conclusion: Task 3. Prove the quality composition of FeSO 4
Conclusion: |
FeSO4+
“Practical work No. 2 - 9th grade”
| Practical work No. 2 Safety briefing. Goal of the work: Solution of experimental problems consisting of a chain of transformations. Equipment: Rack with test tubes. Reagents Option 1: MgSO 4 – MgCl 2 – Mg (OH) 2 - MgSO 4
Conclusion: | Practical work No. 2 Carrying out a chain of chemical transformations of metals Safety briefing. Purpose of work s: Solving experimental problems consisting of a chain of transformations. Equipment: Rack with test tubes. Reagents: Copper sulfate CuSO 4, alkali NaOH, hydrochloric acid HCl, Fe (paper clip). Option 2: CuSO 4 –Cu (OH) 2 – CuO – Cu
Conclusion: |
FeSO4+
“Practical work No. 3 - 9th grade”
| "Practical work No. 3" Safety briefing. Goal of the work Equipment: Reagents : NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder. Exercise 1. Task2. 4 . Task 3. |
| "Practical work No. 3" Solving experimental problems on the topic “Oxygen subgroup” Safety briefing. Goal of the work: To consolidate theoretical knowledge of qualitative reactions in practice. Equipment: Rack with test tubes, evaporation cup, holder, alcohol lamp. Reagents: Phenolphthalein indicator, AgNO 3, BaCl 2, NaOH, H 2 SO 4, HCl, NaCl, KI, ZnSO 4. : NaOH, K 2 CO 3, BaCl 2, indicator paper, H 2 SO 4, aluminum powder. Exercise 1. Determine in which test tube which of the substances is NaOH, H 2 SO 4, HCl. Task2. Give qualitative reactions for the substances NaCl, KI, ZnSO 4 . Task 3. Obtain from CuO, CuSO 4, and CuSO 4 ∙5H 2 O. |
FeSO4+
“Practical work No. 5 -9 grades”
Practical work No. 5.
Production of carbon monoxide ( IV ) and study of its properties.
Goal of the work: _________________________________________________________________
_____________________________________________________________________
Equipment: ________________________________________________________________
Reagents:
| Name | |
| Hydrochloric acid | |
| Lime water | |
| Sodium carbonate |
Precautionary measures: _____________________________________________________________
_____________________________________________________________________________________
Progress: Present the results of your work in the form of a table
| Experience name | What they were doing? | What did you observe? | Chemical reaction equation (in molecular, complete, abbreviated ionic form) |
| Obtaining carbon dioxide and studying its properties | CaCO 3 + HCl = H 2 O + CO 2 ↔ H 2 CO 3 + Ca(OH) 2 = |
||
| Experience No. 2. Interconversion of carbonates and bicarbonates | CO 2 + Ca(OH) 2 = CaCO 3 + CO 2 + H 2 O ↔ Ca(HCO 3 ) 2 t˚C → |
||
| Experience No. 3. Carbonate recognition | Na 2 CO 3 + HCl = |
Conclusion (fill the gaps):
Carbon monoxide (IV) can be obtained in the laboratory_____________________________________________
_____________________________________________________________________________________
The following properties of CO 2 were discovered:
Physical __________________________________________________________________________Chemical __________________________________________________________________________
_____________________________________________________________________________________
When carbon dioxide is passed through lime water, it first forms _____________ calcium carbonate, which ________________ in excess of carbon dioxide.
Calcium bicarbonate is thermally ____________________, when heated _______________ to form ______________________.
All carbonates can react with ________________ acids to form _________________, this reaction is ___________________________________________________________________________________.
FeSO4+
“Practical work No. 4 - 9th grade”
Practical work No. 4. (9th grade)
Subject:“Obtaining ammonia and studying its properties”
Goal: Obtain ammonia and get acquainted with the properties aqueous solution ammonia.
Equipment and reagents:
Instructions for performing practical work.
Repeat the questions from the textbook: preparation and properties of ammonia, ammonia water and ammonium salts. After that, get to work.
Experience No. 1. Ammonia production .
Assemble a device for producing ammonia.
Place four scoops of ammonium chloride and two scoops of calcium hydroxide into a porcelain cup. Mix the mixture with a spatula and pour into a dry test tube. Close it with a stopper with a gas outlet tube and secure it in the tripod leg (pay attention to the tilt of the test tube with the mixture). Place a dry test tube on the gas outlet tube to collect ammonia and close the hole with a cotton swab.
Warm the test tube with a mixture of ammonium chloride and calcium hydroxide slightly (2-3 movements of the flame), and then heat it in the place where the mixture is located. To detect ammonia, hold a damp phenolphthalein paper to the opening of an upside-down test tube. Having found ammonia, bring a glass rod moistened with a solution of hydrochloric acid to the opening of the test tube. What are you observing? What chemical composition particulate matter (smoke) generated? Write the reaction equation.
Stop heating the mixture. Carefully remove the test tube in which the ammonia is collected from the gas outlet tube, holding it upside down (immediately after removing the test tube with ammonia from it, cover the end of the gas outlet tube with a piece of wet cotton wool).
Immediately close the opening of the removed test tube with your thumb and lower it into a vessel with water. Remove your finger only under water. What are you observing? Why did the water rise in the test tube? Close the hole of the test tube under water again with your finger and remove it from the vessel.
Answer the questions
1. Why does a test tube with a mixture of substances to obtain ammonia need to be secured in the tripod leg at an angle with a raised bottom?
2. Why is ammonia collected in a test tube turned upside down? What other gases can be collected this way?
3. How to prove that an aqueous solution of ammonia contains hydroxide ions?
Perform the following experiments with the resulting aqueous ammonia solution.
Studying the properties of an aqueous solution of ammonia
Experience No. 1. Pour 2-3 ml of aqueous ammonia solution into a test tube and add 2-3 drops of phenolphthalein. What is the color of the solution? Heat this solution to a boil. How will the color of the solution change? What caused this change?
Experience No. 2. Pour 2-3 ml of aqueous ammonia solution into a test tube. Add 2-3 drops of phenolphthalein and add sulfuric acid solution drop by drop until the crimson color disappears. Why did the color disappear? Write the ionic equations for the reaction.
Write a report on your work. Draw a conclusion.
| Name of the experience. | Observations. Drawings. | Reaction equations | |
All video experiments on this work can be viewed on the Digital Educational Resources website.
FeSO4+
“Practical work 9th grade equipment and reagents”
Practical work 9th grade
| Job title | Equipment and reagents |
|
| Preparation of metal compounds and study of their properties | Equipment: Rack with test tubes. Reagents: AlCl 3, NaOH, HCl, CaCL 2, AgNO 3. |
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| Carrying out a chain of chemical transformations of metals | Equipment: Rack with test tubes. Reagents: Magnesium sulfate MgSO 4, alkali NaOH, barium chloride BaCl 2. |
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| Oxygen subgroup | Equipment: Rack with test tubes, evaporation cup, holder, alcohol lamp. Reagents: Phenolphthalein indicator, AgNO 3, BaCl 2, NaOH, H 2 SO 4, HCl, NaCl, KI, ZnSO 4. |
|
| Obtaining ammonia and studying its properties | Equipment and reagents: alcohol lamp, metal stand, stopper with gas outlet tube, spatula, porcelain cup, glass rod, 5 test tubes, cotton swab, crystallizer half filled with water, phenolphthalein paper; ammonium chloride, calcium hydroxide, ammonia solution (1%), sulfuric acid solution (1:5), hydrochloric acid solution (1:3). |
|
| Obtaining carbon dioxide, studying its properties | Equipment: rack with test tubes, stopper with gas outlet tube Reagents: marble, hydrochloric acid, lime water, sodium carbonate |
Practical work No. 1.
The influence of various factors on the rate of a chemical reaction.
Target: consider the influence of various factors on the rate of a chemical reaction.
Equipment and reagents:test tubes, alcohol lamp, holder, stand for test tubes, zinc, magnesium, iron: granules and powder, solutions of sulfuric (1:5, 1:10) and hydrochloric acid, hydrogen peroxide, manganese (IV) oxide, copper (II) oxide.
Progress:
EXPERIMENT 1. Influence of the nature of the reacting substances.
EXPERIMENT 2. Effect of concentration of reactants.
EXPERIMENT 3. Effect of contact area of reacting substances.
EXPERIMENT 4. Effect of temperature.
Place some black copper (II) oxide powder in each test tube and pour a sulfuric acid solution into both test tubes. Heat one of the test tubes
EXPERIMENT 5. Effect of catalyst.
2 O 2 2 . In which test tube does the reaction proceed faster? Why?
Present your work in the form of a table:
The considered factor influencing the rate of chemical. reactions | Description of the experiment | Observations to judge the speed of the reaction | Reaction equations | Conclusion |
Experience 1. Influence of the nature of reacting substances. | Pour 2 ml of hydrochloric acid solution into three test tubes. Place a piece of magnesium in the first glass, a zinc granule in the second glass, and a piece of iron in the third. Observe the speed of the three reactions. Which reaction is the fastest and why? | Gas evolution occurs most rapidly in a test tube with magnesium. | Mg + 2HCl → MgCl 2 +H 2 Zn + 2HCl → ZnCl 2 + H 2 Fe + 2HCl → FeCl 2 + H 2 | The rate of a chemical reaction depends on the nature of the reactants. Magnesium has the most powerful restorative properties. |
Experience 2. Effect of concentration of reactants. | In two test tubes, tilt them, lower a zinc granule, carefully pour sulfuric acid solutions: into the first test tube, an acid solution of 1:5, into the second - 1:10. In which of them is the reaction faster? | In the first test tube, gas is released more intensely. | Zn + H 2 SO 4 → ZnSO 4 + H 2 | The higher the concentration of reactants, the more often their particles collide and the higher the rate of the chemical reaction. |
Experience 3. Influence of the contact area of reacting substances. | Pour a little iron powder into one test tube, put an iron clip into the other, and pour 2 ml of diluted hydrochloric acid (1:2) into both test tubes.In which test tube does the reaction proceed faster? Why? | Gas evolution occurs faster in a test tube with iron powder. | Fe + 2HCl → FeCl 2 + H 2 | The larger the contact area of the reacting substances, the higher the rate of the chemical reaction. |
Experience 4. Effect of temperature. | Place some black copper(II) oxide powder in two test tubes and pour a sulfuric acid solution into both test tubes. Heat one of the test tubes. In which test tube does the reaction proceed faster? Why? | The dissolution of copper (II) oxide and the formation of a blue solution occurs faster when heated. | СuO + H 2 SO 4 CuSO 4 + H 2 O | As the temperature increases, the speed of particle movement and the rate of chemical reaction increase. |
Experience 5. The influence of the catalyst. | Pour 2 ml of hydrogen peroxide H into two test tubes 2 O 2 , add several crystals of manganese (IV) oxide MnO to one of the test tubes 2 . In which test tube does the reaction proceed faster? Why? | In the presence of manganese (IV) oxide, rapid evolution of gas bubbles occurs. | 2H 2 O 2 2H 2 O + O 2 | Manganese (IV) oxide is a catalyst that accelerates the decomposition reaction of hydrogen peroxide. |
Conclusion: The rate of a chemical reaction depends on the conditions: the nature of the reacting substances, the contact area, the concentration, the temperature, and the presence of catalysts.
Practical work No. 2.
Solving experimental problems on the topic “Electrolytic dissociation”.
Target: learn to apply theoretical knowledge to experimentally solve problems.
Equipment and reagents:test tubes, solutions of sulfuric acid, sodium chloride, sodium sulfate, hydrochloric acid, silver nitrate, barium chloride, indicators, copper (II) sulfate, sodium hydroxide.
Progress:
Remember the safety rules when performing a chemical experiment.
- Many substances can cause burns if they come into contact with the skin. Never handle substances with your hands.
- Some substances have an unpleasant odor, and their vapors can cause poisoning. Do not bring an open bottle close to your face.
- In a chemical laboratory, even known substances are not tasted; they may contain impurities that are poisonous to humans.
- Acids are caustic substances. They destroy and irritate the skin and mucous membranes.
- If acid or alkali gets on the skin, it should be washed immediately with plenty of running water.
- Glass is a brittle material with low impact resistance and low bending strength. It is strictly forbidden to use cookware that has cracks or broken edges.
- Experiments should be carried out with the number of substances specified in the methodological manual for each experiment.
- Do not touch anything on the tables without the teacher's permission.
- Keep quiet while conducting an experiment or writing a report.
- After work, clean up your work place.
Task No. 1. Determine experimentally the composition of solutions found without labels: sulfuric acid, sodium chloride, sodium sulfate.
Substance reagent | H2SO4 | NaCl | Na2SO4 |
litmus | Red color | no changes | no changes |
BaCl2 | no changes | BaSO 4 ↓ white |
|
AgNO3 | AgCl↓ white curd | ||
Tube No.: |
H 2 SO 4 → 2H + + SO 4 2-
Ba 2+ + SO 4 2- → BaSO 4 ↓
NaCl + AgNO 3 → NaNO 3 + AgCl↓
Ag + + Cl - → AgCl ↓
Task No. 2. Confirm the quality of the substances:
1) Hydrochloric acid.
Hydrochloric acid dissociates into ions:НCl → H + + Cl -
Qualitative reaction for hydrogen cation - litmus. A red color is formed.
A qualitative reaction to the chloride anion is interaction with silver nitrate, a white cheesy precipitate is formed.
НCl + AgNO 3 → НNO 3 + AgCl↓
Ag + + Cl - → AgCl ↓
2) Copper (II) sulfate.
Copper(II) sulfate dissociates into ions: CuSO 4 → Cu 2+ + SO 4 2-
A qualitative reaction to sulfate ion is interaction with barium chloride. A white precipitate of barium sulfate is formed:
CuSO 4 + BaCl 2 → CuCl 2 + BaSO 4 ↓
Ba 2+ + SO 4 2- → BaSO 4 ↓
Qualitative reaction to copper cation Cu 2+ - interaction with sodium hydroxide solution. A blue gelatinous precipitate of copper (II) hydroxide is formed:
CuSO 4 + 2NaOH → Na 2 SO 4 + Cu(OH) 2 ↓
Cu 2+ + 2OH - → Cu(OH) 2 ↓
Conclusion:
Practical work No. 3.
Preparation of ammonia and study of its properties. Familiarization with chemical properties aqueous ammonia solution.
Target: 1. Strengthen the ability to receive gases and collect them, taking into account the relative density in the air.
2. Study the properties of ammonia and ammonia water, learn to obtain and recognize ammonium salts.
Equipment and reagents:laboratory stand, alcohol lamp, stopper with gas outlet tube, spatula, porcelain mortar and pestle, crystallizer with water, splinter, cotton swab, test tubes, litmus paper, ammonium chloride, ammonium sulfate, calcium hydroxide, 1% ammonia solution, solutions of hydrochloric and sulfuric acids , sodium hydroxide.
Progress:
Remember the safety rules when performing a chemical experiment.
- Many substances can cause burns if they come into contact with the skin. Never handle substances with your hands.
- Some substances have an unpleasant odor, and their vapors can cause poisoning. Do not bring an open bottle close to your face.
- In a chemical laboratory, even known substances are not tasted; they may contain impurities that are poisonous to humans.
- Acids are caustic substances. They destroy and irritate the skin and mucous membranes.
- Alkalis are caustic substances. They destroy and irritate the skin and mucous membranes. They can cause complete loss of vision.
- If acid or alkali gets on the skin, it should be washed immediately with plenty of running water.
- Ammonia requires careful handling due to its physiological activity and affects the respiratory tract (dehydration).Ammonia, which will be released when ammonium salts interact with alkalis, is very soluble in water, and therefore in the moisture of the mucous membrane of the eyes. They may become irritated. If this happens, rinse your eyes with water.
- If you light a spirit lamp immediately after removing the cap, the film of alcohol on the neck of the spirit lamp lights up exactly at the place where the cap is adjacent to the neck. The flame penetrates under the disk with the tube, and the alcohol vapor inside the tank ignites. An explosion may occur and the disc may be ejected along with the wick. To avoid this, lift the wick disc for a few seconds to release the vapor. If vapors ignite, quickly set the items aside (practice book) and call the teacher.
- Light the alcohol lamp only with matches, extinguish it with a lid or cap, covering it on top.
- It is prohibited to transfer a lit alcohol lamp or light one alcohol lamp from another.
- When heating a substance in a test tube, it must first be heated; the opening of the test tube during heating must be directed away from itself and its neighbor.
- Glass is a brittle material with low impact resistance and low bending strength. It is strictly forbidden to use cookware that has cracks or broken edges.
- Experiments should be carried out with the number of substances specified in the methodological manual for each experiment.
- Do not touch anything on the tables without the teacher's permission.
- Keep quiet while conducting an experiment or writing a report.
- After work, clean up your work place.
Page 116-117
Experience name | What they were doing | Observations, drawings | Reaction equations | Conclusion |
Experience 1. Obtaining ammonia and dissolving it in water. | In a porcelain mortar, mix equal volumes of solid ammonium chloride NH 4 Cl and calcium hydroxide Ca(OH) 2 . Pour the prepared mixture into a test tube to fill 1/3 of its volume. Close the test tube with a stopper with a gas outlet tube. Secure the test tube at an angle so that the bottom is slightly higher than the stopper. Explain why? Place a dry test tube on the end of the gas outlet tube, closing the hole at the bottom with a cotton swab. Heat the mixture: first the entire test tube, then the reaction mixture. Why is ammonia collected in a test tube turned upside down? When you smell ammonia, plug the test tube with your finger and, without inverting, immerse it in a crystallizer with water. What are you observing? What causes this phenomenon? Invert the test tube with the solution and test with phenolphthalein. What are you observing? Draw a conclusion. | drawing ris1.jpg Water vapor condenses at the plug. There is a smell of ammonia. Rapid absorption of water into a test tube. Appearance of crimson color. | Ca(OH) 2 + 2NH 4 C1 CaC1 2 + 2NH 3 + 2H 2 O NH 3 + H 2 O ⇄ NH 3 H 2 O ⇄ NH 4 + +OH - | The neck of the test tube is tilted slightly downward so that drops of water do not flow onto the hotter walls of the test tube, otherwise it may crack. Ammonia is a gas, almost 2 times lighter than air, so it is collected in a test tube turned upside down. Ammonia dissolves very well in water, creating a vacuum in the test tube. The environment is alkaline. |
Experience 2. Reaction of ammonia with acids. | Lower the gas outlet tube into test tubes ¼ filled with solutions of hydrochloric and sulfuric acids. What are you observing? | “White smoke” appears above the surface of acid solutions - crystalline ammonium chloride and sulfate. | NH 3 + HCl → NH 4 Cl NH 3 + H 2 SO 4 → (NH 4 ) 2 SO 4 | Ammonia reacts actively with acids. |
Experience 3. Interaction of ammonium salts with alkalis (recognition of ammonium salts) | Place some crystalline ammonium sulfate in a test tube, add 2 ml of sodium hydroxide solution, heat slightly. How do you feel? Apply wet litmus paper to the opening of the test tube. What are you observing? Conclude how to recognize ammonium salts. | A gas with a pungent odor is released. She turns blue. | (NH 4 ) 2 SO 4 + 2NaOH →Na 2 SO 4 + 2NH 3 + 2H 2 O NH 3 + H 2 O ⇄ NH 3 H 2 O ⇄ NH 4 + +OH - | The environment is alkaline. A qualitative reaction to ammonium salts is their interaction with alkalis when heated. |
Conclusion: We studied the properties of ammonia, learned how to obtain and recognize ammonium salts.
Practical work No. 4.
Preparation of carbon monoxide (IV) and study of its properties. Recognition of carbonates.
Target: 1. Consolidate knowledge about the properties of carbon dioxide and carbonates.
2. Learn to produce carbon dioxide by metabolic reaction and recognize it.
Equipment and reagents:laboratory stand, stopper with gas outlet tube, beaker, test tubes, litmus, solutions of hydrochloric acid, sodium chloride, sodium carbonate, sodium sulfate, barium chloride, silver nitrate, marble, lime water.
Progress:
Remember the safety rules when performing a chemical experiment.
- In a chemical laboratory, even known substances are not tasted; they may contain impurities that are poisonous to humans.
- Acids are caustic substances. They destroy and irritate the skin and mucous membranes.
- If acid or alkali gets on the skin, it should be washed immediately with plenty of running water.
- It is necessary to work with barium compounds in such a way as to prevent them from entering the mouth, as they are toxic. To obtain severe poisoning, a dose weighing less than 0.5 g is sufficient. After completing work, wash your hands thoroughly with soap and running water.
- Glass is a brittle material with low impact resistance and low bending strength. It is strictly forbidden to use cookware that has cracks or broken edges.
- The test tube is fixed in the holder so that there is a distance of 1 - 1.5 cm from the neck of the test tube to the holder.
- Experiments should be carried out with the number of substances specified in the methodological manual for each experiment.
- Do not touch anything on the tables without the teacher's permission.
- Keep quiet while conducting an experiment or writing a report.
- After work, clean up your work place.
Experience 1 . Preparation of carbon monoxide (IV) and study of its properties. Page 158-159
What they were doing | Observations, drawings | Reaction equations | Conclusion |
Assemble a device for producing gases. Check it for leaks. Place several pieces of marble in a test tube and add 2 ml of dil. of hydrochloric acid. What are you observing? Close the test tube with a stopper with a gas outlet tube and pass the released gas through lime water. What do you are you watching? Continue passing the gas for a few minutes. What are you observing? Place the end of the gas outlet tube in a test tube with 2-3 ml of distilled water and a few drops of litmus and pass carbon dioxide through it. What are you observing? | drawing ris2 Violent gas release. Cloudiness of lime water. The resulting precipitate dissolves. Litmus turns red. | CaCO 3 + 2HCl →CaCl 2 + CO 2 + H 2 O CaCO 3 + 2H + →Ca 2+ + CO 2 + H 2 O CO 2 + Ca(OH) 2 → CaCO 3 ↓ + H 2 O CaCO 3 + H 2 O + CO 2 → Ca(HCO 3 ) 2 CaCO 3 + H 2 O + CO 2 → Ca 2+ +2HCO 3 - CO 2 +H 2 O ↔ H 2 CO 3 | In the laboratory, to produce carbon dioxide, carbonates are treated with a strong acid. Lime water is used to detect carbon dioxide. When there is an excess of carbon dioxide, insoluble carbonates turn into soluble bicarbonates. When carbon dioxide dissolves, carbonic acid is formed, i.e. carbon dioxide is an acidic oxide. |
Conclusion: 1. In the laboratory, carbon dioxide is produced by the action of hydrochloric acid on carbonates.
2. A qualitative reaction to carbon dioxide is the turbidity of lime water.
Experience 2 . Recognition of carbonates.
Three test tubes contain solutions of the following substances: sodium chloride, sodium sulfate, sodium carbonate. Recognize these substances by determining the sequence of operations.
Substance reagent | NaCl | Na2SO4 | Na 2 CO 3 |
no changes | no changes | “boiling” of CO 2 |
|
BaCl2 | no changes | BaSO 4 ↓ white | |
AgNO3 | AgCl↓ white curd | ||
Tube No.: |
Na 2 CO 3 + 2HCl → 2NaCl + CO 2 + H 2 O
2H + + CO 3 2- → CO 2 + H 2 O
Na 2 SO 4 + BaCl 2 → 2NaCl + BaSO 4 ↓
Ba 2+ + SO 4 2- → BaSO 4 ↓
NaCl + AgNO 3 → NaNO3 + AgCl↓
Ag+ + Cl- → AgCl ↓
Conclusion:1.Substances can be recognized using qualitative reactions.
2. Qualitative reaction to carbonate ion - interaction of carbonates with strong acids.
Practical work No. 5.
Determination of the qualitative composition of organic matter.
Target:learn to experimentally determine the qualitative composition of organic substances.
Equipment and reagents:laboratory stand, alcohol lamp, stopper with gas outlet tube, test tubes, anhydrous copper (II) sulfate, copper (II) oxide, petroleum jelly, lime water.
Progress:
Remember the safety rules when performing a chemical experiment.
- Alkalis are caustic substances. They destroy and irritate the skin and mucous membranes. They can cause complete loss of vision.
- If acid or alkali gets on the skin, it should be washed immediately with plenty of running water.
- If you light a spirit lamp immediately after removing the cap, the film of alcohol on the neck of the spirit lamp lights up exactly at the place where the cap is adjacent to the neck. The flame penetrates under the disk with the tube, and the alcohol vapor inside the tank ignites. An explosion may occur and the disc may be ejected along with the wick. To avoid this, lift the wick disc for a few seconds to release the vapor. If vapors ignite, quickly set the items aside (practice book) and call the teacher.
- Light the alcohol lamp only with matches, extinguish it with a lid or cap, covering it on top.
- It is prohibited to transfer a lit alcohol lamp or light one alcohol lamp from another.
- Glass is a brittle material with low impact resistance and low bending strength. It is strictly forbidden to use cookware that has cracks or broken edges.
- Experiments should be carried out with the number of substances specified in the methodological manual for each experiment.
- Do not touch anything on the tables without the teacher's permission.
- Keep quiet while conducting an experiment or writing a report.
- After work, clean up your work place.
Page 184
What they were doing | Observations, drawings | Reaction equations | Conclusion |
Assemble the device. Place a pea-sized amount of petroleum jelly and copper (II) oxide (take 3 times more) at the bottom of the test tube and mix. Using a spatula, place anhydrous copper (II) sulfate, a white powder, on the inside of the test tube, closer to the hole. Pour a solution of lime water into the receiver tube and lower the gas outlet tube into it. First heat the entire test tube, then the bottom of the test tube. Note signs of reactions occurring: a) with a mixture of petroleum jelly and copper (II) oxide; b) with white copper (II) sulfate powder; c) with lime water. | figure ris3 a) Formation of a red coating on a mixture of petroleum jelly and copper (II) oxide. b) White CuSO powder4 turns blue. c) Lime water becomes cloudy. | WITH15 N32 + 46CuO →15CO2 +16H2 O+46Cu CuSO4 +5H2 О→ CuSO4 5H2 ABOUT CO2 +Ca(OH)2 →CaCO3 ↓+H2 O | . CuO is reduced to copper. CuO is an oxidizing agent, Vaseline is a reducing agent. When Vaseline is oxidized by CuO, water vapor is formed, which reacts with anhydrous CuSO4 . That. Vaseline contains hydrogen. When Vaseline oxidizes with CuO, carbon dioxide is formed, which reacts with lime water. That. Vaseline contains carbon. |
Conclusion:Vaseline contains carbon and hydrogen atoms, because As a result of the oxidation of petroleum jelly with copper (II) oxide, carbon dioxide and water are formed.
Practical work No. 6.
Solving experimental problems on the topic “Metals”.
Target:study the properties of metals and their compounds.
Equipment and reagents:
Option 1: test tube rack, test tubes, iron, solutions of nitric acid, sulfuric acid, hydrochloric acid, sodium hydroxide, potassium chloride, potassium carbonate, copper (II) chloride, iron (II) chloride, nickel (II) sulfate,silver nitrate.
Option 2: test tube rack, test tubes, solutions of nitric and hydrochloric acid, iron (III) chloride, sodium hydroxide, potassium thiocyanate, sodium phosphate, zinc sulfate, sodium bromide,silver nitrate.
Progress:
Remember the safety rules when performing a chemical experiment.
- In a chemical laboratory, even known substances are not tasted; they may contain impurities that are poisonous to humans.
- Acids are caustic substances. They destroy and irritate the skin and mucous membranes.
- Alkalis are caustic substances. They destroy and irritate the skin and mucous membranes. They can cause complete loss of vision.
- If acid or alkali gets on the skin, it should be washed immediately with plenty of running water.
- Copper compounds in the form of dust, if they come into contact with the skin, especially in places of microtrauma, can cause irritation and lead to mild allergies.
- All nitrates have a burning effect on the skin and mucous membranes. Silver nitrate (lapis) decomposes when exposed to sunlight. Upon contact with skin, it causes darkening.
- Rodanide compounds are compounds with increased physiological activity. When working with them, you should use personal protective equipment and observe personal hygiene rules.Do not allow drugs to enter the body!
- Glass is a brittle material with low impact resistance and low bending strength. It is strictly forbidden to use cookware that has cracks or broken edges.
- The test tube is fixed in the holder so that there is a distance of 1 - 1.5 cm from the neck of the test tube to the holder.
- Experiments should be carried out with the number of substances specified in the methodological manual for each experiment.
- Do not touch anything on the tables without the teacher's permission.
- Keep quiet while conducting an experiment or writing a report.
- After work, clean up your work place.
Page 255
Option I
Exercise 1.
Using the necessary reagents and equipment, perform the following transformations:
Fe → FeSO4 →Fe(OH)2 → Fe(NO3 ) 2
What they were doing | Observations | Reaction equations |
1. Place iron filings in a solution of sulfuric acid. | Gas release. | Fe + H2 SO4 →FeSO4 + N2 Fe + 2H+ →Fe2+ + N2 |
2. After some time, add a few drops of alkali to the resulting solution. | A greenish gelatinous precipitate forms. | FeSO4 + 2NaOH → Fe(OH)2 ↓+Na2 SO4 Fe2+ +2OH- →Fe(OH)2 ↓ |
3. | The precipitate dissolves.Reaction equations |
|
1. Add a few drops of alkali to the solution of nickel (II) sulfate. | A light green precipitate forms. | NiSO4 + 2NaOH → Ni(OH)2 ↓+Na2 SO4 Ni2+ +2OH- →Ni(OH)2 ↓ |
| The precipitate dissolves. | Ni(OH)2 + 2HCl → NiCl2 + 2H2 O Ni(OH)2 + 2H+ → Ni2+ + 2H2 O |
3. To anotheradd conc. to the resulting precipitate in a test tube. alkali solution. | No changes. |
Conclusion:Nickel (II) hydroxide is a light green precipitate that exhibits basic properties.
Task 3.Offer the most rational way determination of salts whose solutions are in numbered test tubes: KCl, K2 CO3 , CuCl2 , FeCl2. ↓ blue gelatinous
Fe(OH)2 ↓ greenish gelatinous
HCl
no changes
“boiling” of CO2
AgNO3
AgCl↓
white
curdled
Tube No.:
CuCl2 + 2NaOH → Cu(OH)2 ↓ + 2NaCl
Cu2+ +2OH- → Cu(OH)2 ↓
FeCl2 + 2NaOH → Fe(OH)2 ↓ + 2NaCl
Fe2+ +2OH- →Fe(OH)2 ↓
K2 CO3 + 2HCl → 2KCl + CO2 +H2 O
2H+ + CO3 2- → CO2 +H2 O
KCl + AgNO3 → KNO3 + AgCl↓
Ag+ + Cl- → AgCl ↓
Conclusion:Substances can be recognized using qualitative reactions.
Option II:
Exercise 1.
Using the necessary reagents and equipment, perform the following transformations
FeCl3 →Fe(OH)↓
2. Add a solution of nitric acid to the resulting precipitate.
The precipitate dissolves and a yellow solution is formed.
Fe(OH)3 +3HNO3 → Fe(NO3 ) 3 + 3H2 O
Fe(OH)3 + 3H+ → Fe3+ + 3H2 O
3. Add a few drops of potassium thiocyanate to the solution of iron (III) nitrate.
The appearance of a blood-red color.
Fe(NO3 ) 3 + 3KCNS → Fe(CNS)3 + 3KNO3
Fe3+ + 3CNS- ↔Fe(CNS)3
Conclusion:The transformations of chemical reactions were experimentally carried out.
Task 2.Prepare iron(III) hydroxide and study its properties.
What they were doing | Observations | Reaction equations |
1. Add a few drops of alkali to the solution of iron (III) chloride. | A brown precipitate forms. | FeCl3 + 3NaOH → Fe(OH)3 ↓ + 3NaCl Fe3+ +3OH- →Fe(OH)3 ↓ |
2. The resulting precipitate is divided into 2 parts. In oneAdd a solution of hydrochloric acid to the resulting precipitate in a test tube. | The precipitate dissolves. | Fe(OH)3 + 3HCl → FeCl3 + 3H2 O Fe(OH)3 + 3H+ → Fe3+ + 3H2 O |
3. To anotheradd conc. to the resulting precipitate in a test tube. alkali solution, heat. | The precipitate dissolves. | t Fe(OH)3 + 3NaOH → Na3 Fe(OH)3 +3OH- → 3- |
Conclusion:Iron (III) hydroxide is a brown precipitate that exhibits amphoteric properties.
Task 3.Suggest the most rational way to determine salts, solutions of which are in numbered test tubes: Na3 P.O.4
Fe(OH)3 ↓
brown
Zn(OH)2 ↓
white
no changes
AgNO3
Ag3 P.O.4 ↓
yellow
AgBr↓
yellowish
curdled
Tube No.:
FeCl3 + 3NaOH → Fe(OH)3 ↓ + 3NaCl
Fe3+ +3OH- →Fe(OH)3 ↓
ZnSO4 + 2NaOH → Zn(OH)2 ↓+Na2 SO4
Zn2+ +2OH- → Zn(OH)2 ↓
Na3 P.O.4 + 3AgNO3 → 3NaNO3 +Ag3 P.O.4 ↓
3Ag+ +PO4 3- → Ag3 P.O.4 ↓
NaBr + AgNO3 → NaNO3 + AgBr↓
Ag+ +Br- → AgBr ↓
Conclusion:Substances can be recognized using qualitative reactions.