Chemistry laboratory work 9.

Practical work No. 1.

The influence of various factors on the rate of a chemical reaction.

Goal: consider the influence of various factors on the rate of a chemical reaction.

Equipment and reagents:test tubes, alcohol lamp, holder, test tube rack, zinc, magnesium, iron: granules and powder, solutions of sulfuric (1: 5, 1:10) and hydrochloric acid, hydrogen peroxide, manganese (IV) oxide, copper (II) oxide.

Working process:

EXPERIENCE 1. Influence of the nature of the reacting substances.

EXPERIENCE 2. Influence of the concentration of reactants.

EXPERIENCE 3. Influence of the contact area of \u200b\u200bthe reacting substances.

EXPERIENCE 4. Influence of temperature.

Put a little black powder of copper (II) oxide in de test tubes, add a solution of sulfuric acid to both test tubes. Heat one of the tubes

EXPERIENCE 5. The influence of the catalyst.

2 O 2 2 ... In which test tube does the reaction go faster? Why?

Draw up the work in the form of a table:

The considered factor affecting the rate of chemical. reactions	Experiment Description	Observations to judge the reaction rate	Reaction equations	Conclusion
Experience 1. Influence of the nature of the reacting substances.	Pour 2 ml of hydrochloric acid solution into three tubes. Put 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 violently in a test tube containing 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 reducing properties.
Experience 2. Influence of the concentration of reactants.	In two test tubes, tilting them, lower them over the zinc granule, carefully pour the solutions of sulfuric acid: in the first test tube the acid solution is 1: 5, in the second - 1:10. In which of them does the reaction go faster?	In the first test tube, the gas is released more intensively.	Zn + H 2 SO 4 → ZnSO 4 + H 2	The higher the concentration of the reacting substances, the more often the collisions of their particles and the higher the rate of the chemical reaction.
Experience 3. Influence of the contact area of \u200b\u200bthe reactants.	Pour a little iron powder into one tube, put an iron clip into the other, and add 2 ml of diluted hydrochloric acid (1: 2) to both tubes.In which test tube does the reaction go faster? Why?	Gas evolution proceeds faster in a test tube with iron powder.	Fe + 2HCl → FeCl 2 + H 2	The larger the contact area of \u200b\u200bthe reactants, the higher the rate of the chemical reaction.
Experience 4. Influence of temperature.	Put a little black powder of copper (II) oxide in two test tubes, add a solution of sulfuric acid to both tubes. Heat one of the tubes. In which test tube does the reaction go faster? Why?	The dissolution of copper (II) oxide and the formation of a blue solution is faster when heated.	СuO + H 2 SO 4 CuSO 4 + H 2 O	As the temperature rises, the speed of particle motion and the speed of the chemical reaction increase.
Experience 5. Effect of the catalyst.	Pour 2 ml of hydrogen peroxide H into two test tubes2 O 2 , add a few crystals of manganese (IV) oxide MnO to one of the tubes2 ... In which test tube does the reaction go faster? Why?	In the presence of manganese (IV) oxide, a vigorous evolution of gas bubbles occurs.	2H 2 O 2 2H 2 O + O 2	Manganese (IV) oxide is a catalyst that accelerates the decomposition of hydrogen peroxide.

Conclusion: The rate of a chemical reaction depends on the conditions: on the nature of the reacting substances, on the contact area, on concentration, on temperature, on the presence of catalysts.

Practical work No. 2.

Solving experimental problems on the topic "Electrolytic dissociation".

Goal: learn to apply theoretical knowledge for experimental problem solving.

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.

Working process:

Remember the safety precautions 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 hold an open bottle close to your face.
In a chemical laboratory, even known substances are not tasted; they may contain impurities that are toxic to humans.
Acids are corrosive substances. They destroy and irritate the skin and mucous membranes.
If acid or alkali gets on the skin, rinse it immediately with plenty of running water.
Glass is a brittle material with low impact resistance and low flexural strength. It is strictly forbidden to use cookware with cracks or chipped edges.
Experiments should be carried out with such a number of substances, which are indicated in the methodological manual for each experiment.
Do not touch anything on the tables without the teacher's permission.
Be quiet while conducting an experiment or writing a report.
After work, clean up the workplace.

Task number 1. Define empirically the composition of solutions without labels: sulphuric acid, sodium chloride, sodium sulfate.

Substance reagent	H 2 SO 4	NaCl	Na 2 SO 4
litmus	red color	no change	no change
BaCl 2		no change	BaSO 4 ↓ white
AgNO 3		AgCl ↓ white cheesy
Tube number:

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 number 2. Confirm the qualitative composition of substances:

1) Hydrochloric acid.

Hydrochloric acid dissociates into ions:НCl → H + + Cl -

A qualitative reaction to a hydrogen cation is litmus. A red color is formed.

Qualitative reaction to chloride anion - interaction with silver nitrate, a white curdled precipitate is formed.

НCl + AgNO 3 → НNO 3 + AgCl ↓

Ag + + Cl - → AgCl ↓

2) Copper (II) sulfate.

Copper (II) sulfate dissociates into ions: CuSO4 → Cu 2+ + SO 4 2-

Qualitative reaction for sulfate ion is interaction with barium chloride. A white precipitate of barium sulfate forms:

CuSO 4 + BaCl 2 → CuCl 2 + BaSO 4 ↓

Ba 2+ + SO 4 2- → BaSO 4 ↓

Qualitative reaction for copper cation Cu2+ - 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.

Obtaining ammonia and studying its properties. Familiarization with chemical properties aqueous solution ammonia.

Goal: 1. To consolidate 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 receive and recognize ammonium salts.

Equipment and reagents:laboratory stand, alcohol lamp, stopper with gas outlet tube, spatula, porcelain mortar with 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.

Working process:

Remember the safety precautions 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 hold an open bottle close to your face.
In a chemical laboratory, even known substances are not tasted; they may contain impurities that are toxic to humans.
Acids are corrosive substances. They destroy and irritate the skin and mucous membranes.
Alkalis are corrosive substances. They destroy and irritate the skin and mucous membranes. From them, complete loss of vision is possible.
If acid or alkali gets on the skin, rinse it immediately with plenty of running water.
Ammonia requires careful handling due to physiological activity and damages the airways (dehydration). Ammonia, which will be released during the interaction of ammonium salts with alkalis, is very soluble in water, and hence 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 the spirit lamp immediately after removing the cap, a film of alcohol on the neck of the spirit lamp ignites exactly where the cap adjoins the neck. The flame penetrates under the tube disc and the alcohol vapor inside the reservoir ignites. Explosion and ejection of the disc together with the wick may occur. To avoid this, lift the disc with the wick for a few seconds to remove the vapor. If vapors ignite, quickly set aside objects (notebook for practical work) and call the teacher.

Light the spirit lamp only with matches, extinguish with a lid or cap, covering from above.
It is forbidden to transfer a lighted spirit lamp and light one spirit lamp from another.
When heating a substance in a test tube, it must first be warmed up; the opening of the test tube during heating should be directed away from yourself and the neighbor.
Glass is a brittle material with low impact resistance and low flexural strength. It is strictly forbidden to use cookware with cracks or chipped edges.
Experiments should be carried out with such a number of substances, which are indicated in the methodological manual for each experiment.
Do not touch anything on the tables without the teacher's permission.
Be quiet while conducting an experiment or writing a report.
After work, clean up the workplace.

P. 116-117

Experience name	What they were doing	Observations, drawings	Reaction equations	Conclusion
Experience 1. Getting ammonia and dissolving it in water.	In a porcelain mortar, stir equal volumes of solid ammonium chloride NH4 Cl and calcium hydroxide Ca (OH)2 ... Pour the prepared mixture into a test tube for 1/3 of its volume. Close the tube with a stopper with a gas outlet tube. Secure the 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, covering the bottom with a cotton swab. Heat the mixture: first the whole tube, then the reaction mixture. Why is ammonia collected in an upside-down test tube? When you smell ammonia, plug the tube with your finger and, without inverting, immerse it in a crystallizer with water. What are you seeing? What caused this phenomenon? Invert the test tube with the solution, test with phenolphthalein. What are you seeing? Make a conclusion.	picture ris1.jpg Water vapor condenses at the plug. There is a smell of ammonia. Rapid suction of water into a test tube. The appearance of a raspberry color.	Ca (OH) 2 + 2NH 4 C1 CaCl 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 to prevent water droplets from dripping onto the warmer walls of the 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, a vacuum is created in the test tube. The medium is alkaline.
Experience 2. Interaction of ammonia with acids.	Dip the gas outlet tube into в test tubes filled with solutions of hydrochloric acid with sulfuric acid. What are you seeing?	Above the surface of acid solutions, "white smoke" appears — 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)	Put a little crystalline ammonium sulfate in a test tube, add 2 ml of sodium hydroxide solution, heat slightly. How do you feel? Bring wet litmus paper to the opening of the test tube. What are you seeing? Draw a conclusion on how to recognize ammonium salts.	Gas is emitted with a pungent odor. It 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 medium is alkaline. A qualitative reaction to ammonium salts is their interaction with alkalis when heated.

Conclusion: We studied the properties of ammonia, learn how to receive and recognize ammonium salts.

Practical work No. 4.

Obtaining carbon monoxide (IV) and studying its properties. Recognition of carbonates.

Goal: 1. Consolidate knowledge about the properties of carbon dioxide and carbonates.

2. Learn to receive carbon dioxide by exchange reaction and recognize it.

Equipment and reagents:laboratory tripod, stopper with gas tube, beaker, test tubes, litmus, solutions of hydrochloric acid, sodium chloride, sodium carbonate, sodium sulfate, barium chloride, silver nitrate, marble, lime water.

Working process:

Remember the safety precautions when performing a chemical experiment.

In a chemical laboratory, even known substances are not tasted; they may contain impurities that are toxic to humans.
Acids are corrosive substances. They destroy and irritate the skin and mucous membranes.
If acid or alkali gets on the skin, rinse it immediately with plenty of running water.
Barium compounds should be handled in such a way as to prevent ingestion, as they are toxic. To obtain severe poisoning, a dose weighing less than 0.5 g is sufficient. After completing work, wash hands thoroughly with soap and running water.

Glass is a brittle material with low impact resistance and low flexural strength. It is strictly forbidden to use cookware with cracks or chipped 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 such a number of substances, which are indicated in the methodological manual for each experiment.
Do not touch anything on the tables without the teacher's permission.
Be quiet while conducting an experiment or writing a report.
After work, clean up the workplace.

Test 1 ... Obtaining carbon monoxide (IV) and studying its properties.P. 158-159

What they were doing

Observations, drawings

Reaction equations

Conclusion

Assemble the gas generating device. Check it for leaks. Place a few pieces of marble in a test tube and add 2 ml dil. of hydrochloric acid.

What are you seeing?

Close the tube with a stopper with a gas outlet tube and pass the evolved gas through lime water. What do youwatching?

Continue passing gas for a few minutes. What are you seeing?

Place the end of the gas outlet tube into 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 seeing?

figure ris2

Violent gas evolution.

Turbidity of lime water.

The formed 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 obtain carbon dioxide, carbonates are treated with a strong acid.

Lime water is used to detect carbon dioxide.

With an excess of carbon dioxide, insoluble carbonates are converted into soluble bicarbonates.

When carbon dioxide dissolves, carbonic acid is formed. 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.

Test 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	Na 2 SO 4	Na 2 CO 3
	no change	no change	"Boiling" CO 2
BaCl 2	no change	BaSO 4 ↓ white
AgNO 3	AgCl ↓ white cheesy
Tube number:

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. It is possible to recognize substances 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.

Goal:learn to empirically determine the qualitative composition of organic substances.

Equipment and reagents:laboratory stand, spirit lamp, stopper with gas outlet tube, test tubes, anhydrous copper (II) sulfate, copper (II) oxide, petroleum jelly, lime water.

Working process:

Remember the safety precautions when performing a chemical experiment.

Alkalis are corrosive substances. They destroy and irritate the skin and mucous membranes. From them, complete loss of vision is possible.
If acid or alkali gets on the skin, rinse it immediately with plenty of running water.
If you light the spirit lamp immediately after removing the cap, a film of alcohol on the neck of the spirit lamp ignites exactly where the cap adjoins the neck. The flame penetrates under the tube disc and alcohol vapors inside the reservoir ignite. Explosion and ejection of the disc together with the wick may occur. To avoid this, lift the disc with the wick for a few seconds to remove the vapor. If vapors ignite, quickly set aside the objects (practice notebook) and call the teacher.

Light the spirit lamp only with matches, extinguish with a lid or cap, covering from above.
It is forbidden to transfer a lighted spirit lamp and light one spirit lamp from another.
Glass is a brittle material with low impact resistance and low flexural strength. It is strictly forbidden to use cookware with cracks or chipped edges.
Experiments should be carried out with such a number of substances, which are indicated in the methodological manual for each experiment.
Do not touch anything on the tables without the teacher's permission.
Be quiet while conducting an experiment or writing a report.
After work, clean up the workplace.

P. 184

What they were doing

Observations, drawings

Reaction equations

Conclusion

Assemble the device.

At the bottom of the test tube, place (about a pea) petroleum jelly, copper (II) oxide (take 3 times more), mix. On the inside of the tube, close to the hole, place anhydrous copper (II) sulfate - powder with a spatula white... Pour lime water solution into the receiving tube and lower the gas outlet tube into it. Warm up the whole tube first, then the bottom of the tube.

Note the signs of reactions occurring:

a) with a mixture of petroleum jelly and copper oxide (II);

b) with white powder of copper (II) sulfate;

c) with lime water.

figure ris3

a) Formation of red plaque on a mixture of petroleum jelly and copper (II) oxide.

b) White powder CuSO4 becomes blue.

c) Lime water becomes cloudy.

FROM15 H32 + 46CuO → 15CO2 + 16H2 O + 46Cu

CuSO4 + 5H2 O → CuSO4 5H2 ABOUT

CO2 + Ca (OH)2 → CaCO3 ↓ + H2 O

Reduction of CuO to copper occurs. CuO is an oxidizing agent, petroleum jelly is a reducing agent.

The oxidation of vaseline CuO produces water vapor, which reacts with anhydrous CuSO4 ... So petrolatum contains hydrogen.

The oxidation of Vaseline CuO produces carbon dioxide, which reacts with lime water. So petroleum jelly contains carbon.

Conclusion:Vaseline contains carbon and hydrogen atoms. 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".

Goal:study the properties of metals and their compounds.

Equipment and reagents:

Option 1: a rack for test tubes, 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: a rack for test tubes, test tubes, solutions of nitric and hydrochloric acid, iron (III) chloride, sodium hydroxide, potassium thiocyanate, sodium phosphate, zinc sulfate, sodium bromide,silver nitrate.

Working process:

Remember the safety precautions when performing a chemical experiment.

In a chemical laboratory, even known substances are not tasted; they may contain impurities that are toxic to humans.
Acids are corrosive substances. They destroy and irritate the skin and mucous membranes.
Alkalis are corrosive substances. They destroy and irritate the skin and mucous membranes. From them, complete loss of vision is possible.
If acid or alkali gets on the skin, rinse it immediately with plenty of running water.
Copper compounds in the form of dust in 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. Causes skin darkening on contact.
Rodanides are compounds with increased physiological activity. When working with them, you should use personal protective equipment, observe the rules of personal hygiene.Do not allow drugs to enter the body!

Glass is a brittle material with low impact resistance and low flexural strength. It is strictly forbidden to use cookware with cracks or chipped 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 such a number of substances, which are indicated in the methodological manual for each experiment.
Do not touch anything on the tables without the teacher's permission.
Be quiet while conducting an experiment or writing a report.
After work, clean up the workplace.

P. 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. We place iron shavings in a sulfuric acid solution.	Gas evolution.	Fe + H2 SO4 → FeSO4 + H2 Fe + 2H+ → Fe2+ + H2
2. After a while, add a few drops of alkali to the resulting solution.	A greenish gelatinous precipitate is formed.	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 nickel (II) sulfate solution.	A light green precipitate is formed.	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 a test tube to the resulting sediment with conc. alkali solution.	No changes.

Conclusion:Nickel (II) hydroxide is a light green precipitate that exhibits basic properties.

Task 3.Suggest the most rational way to determine salts, solutions of which are in numbered test tubes: KCl, K2 CO3 , CuCl2 , FeCl2. ↓ blue gelatinous

Fe (OH)2 ↓ greenish gelatinous

HCl

no change

"Boiling" CO2

AgNO3

AgCl ↓

white

cheesy

Tube number:

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 required reagents and equipment, perform the following transformations

FeCl3 → Fe (OH)↓

2. Add a nitric acid solution to the resulting precipitate.

The precipitate dissolves, 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 coloration.

Fe (NO3 ) 3 + 3KCNS → Fe (CNS)3 + 3KNO3

Fe3+ + 3CNS- ↔ Fe (CNS)3

Conclusion:The transformations of chemical reactions were carried out experimentally.

Task 2.Prepare iron (III) hydroxide and research its properties.

What they were doing	Observations	Reaction equations
1. Add a few drops of alkali to the iron (III) chloride solution.	A brown precipitate is formed.	FeCl3 + 3NaOH → Fe (OH)3 ↓ + 3NaCl Fe3+ + 3OH- → Fe (OH)3 ↓
2. The resulting sediment is divided into 2 parts. In oneadd hydrochloric acid solution to the test tube.	The precipitate dissolves.	Fe (OH)3 + 3HCl → FeCl3 + 3H2 O Fe (OH)3 + 3H+ → Fe3+ + 3H2 O
3. To anotheradd a test tube to the resulting sediment with conc. 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 PO4

Fe (OH)3 ↓

brown

Zn (OH)2 ↓

white

no change

AgNO3

Ag3 PO4 ↓

yellow

AgBr ↓

yellowish

cheesy

Tube number:

FeCl3 + 3NaOH → Fe (OH)3 ↓ + 3NaCl

Fe3+ + 3OH- → Fe (OH)3 ↓

ZnSO4 + 2NaOH → Zn (OH)2 ↓ + Na2 SO4

Zn2+ + 2OH- → Zn (OH)2 ↓

Na3 PO4 + 3AgNO3 → 3NaNO3 + Ag3 PO4 ↓

3Ag+ + PO4 3- → Ag3 PO4 ↓

NaBr + AgNO3 → NaNO3 + AgBr ↓

Ag+ + Br- → AgBr ↓

Conclusion:Substances can be recognized using qualitative reactions.

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The manual is part of the educational-methodical package for the 9th grade of O.S. Gabrielyan. The notebook contains instructions for 17 laboratory experiments and practical work provided by the program.

Familiarization with physical properties metals.
Goal. Get acquainted with the physical properties of simple substances - metals.
Equipment and reagents: metal samples (magnesium, aluminum, zinc, iron, lead, copper).
Content and order of the experiment
1. Study the physical properties of the substances given out using the following plan.
1. State of aggregation at room temperature.
2. Color.
3. Shine.
4. Plasticity.
5. Thermal conductivity (make a conclusion about this property of metals, observing the experience shown by the teacher).
6. Electrical conductivity (make a conclusion about this property of metals, observing the experience shown by the teacher).
7. Hardness according to the relative hardness scale - Mohs scale - (Appendix 1)
8. Density (Appendix 2).
9. Melting and boiling points (Appendix 2).
2. Prepare the report by completing Table 1.

Foreword.
Signs denoting safety rules when performing chemical experiments, and their decoding.
LABORATORY EXPERIENCES
Laboratory experiment No. 7
Obtaining zinc hydroxide and studying its properties
Laboratory experiment No. 2
Acquaintance with the physical properties of metals.
Laboratory experiment No. 3
Interaction of metals with solutions of acids and salts.
Laboratory experiment No. 4
Acquaintance with samples of natural metal compounds.
Laboratory experiment No. 5
Obtaining aluminum hydroxide and its
interaction with solutions of acids and alkalis.
Laboratory experiment no. B
Qualitative reactions to Fe2 + and Fe3 + ions.
Laboratory experiment No. 7
Qualitative reaction to chloride ion.
Laboratory experiment No. 8
Qualitative reaction to sulfate ion.
Laboratory experiment No. 9
Recognition of ammonium salts.
Laboratory experiment No. 10
Obtaining carbon dioxide and its recognition.
Laboratory experiment No. 11
Qualitative reaction to carbonate ion.
Laboratory experiment No. 12
Acquaintance with natural silicon compounds.
Laboratory experiment No. 13
Acquaintance with the products of the silicate industry.
Laboratory experiment No. 14
Making models of hydrocarbon molecules.
Laboratory experiment No. 15
Glycerin properties.
Laboratory experiment No. 16
Interaction of glucose with copper (II) hydroxide
without heating and with ammonia solution
silver oxide when heated.
Laboratory experiment No. 17
Interaction of starch with iodine.
PRACTICAL WORKS
Practical work No. 1
Implementation of a chain of chemical transformations of metals
Practical work number 2
Obtaining and properties of metal compounds.
Practical work number 3
Solving experimental problems for recognition
and obtaining substances.
Practical work No. 4 Experimental tasks
on the topic "Oxygen subgroup".
Practical work No. 5 Experimental tasks
on the topic “Subgroups Nitrogen and Carbon”.
Practical work number 6
Receiving, collecting and recognizing gases.
Applications
1. Determination of the hardness of substances on the Mohs scale.
2. Density, melting point
and boiling of certain substances and minerals.
3. The names of natural compounds of some chemical elements and the formulas of their main constituent part.
4. Recommendations for the implementation of chains of transformations.
5. Classification of chemical reactions.
6. Determination of ions.

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Notebook for assessing the quality of knowledge in chemistry for the textbook of O.S. Gabrielyan "Chemistry. Grade 9 ", Gabrielyan O.S., Kuptsova A.V., 2014
Chemistry, grade 9, workbook for the textbook of O.S. Gabrielyan "Chemistry, grade 9", Gabrielyan O.S., Sladkov S.A., 2014
Chemistry workbook, grade 9, to the textbook of O.S. Gabrielyan "Chemistry. Grade 9 ", Mikityuk A.D., 2014

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