Materials of the Olympiad tasks of the qualifying stage of the Interregional Chemistry Olympiad for schoolchildren named after academician P.D. Sarkisova

XXXI Mendeleev Olympiad for Schoolchildren in Chemistry was held from May 3 to May 10, 1997 in Yerevan. The Mendeleev Olympiad, in accordance with the decision of the Council of the Federation of Chemical Societies of the CIS countries, has an international status. The direct organizers of the 1997 Olympiad were the Association for chemistry education(Russia) and the Ministry of Education and Science of the Republic of Armenia. The Olympiad received significant sponsorship from the Hayastan National Fund, Yerevan City Hall, Armenian Airlines, Menatep Bank and other organizations.

The work of the Organizing Committee of the Olympiad was carried out under the guidance of
A.R. Petrosyan, Minister of Education and Science of the Republic of Armenia,
P.D. Sarkisova, Academician of the Russian Academy of Sciences, Rector of the Russian Chemical Technical University named after D.I. Mendeleev
Yu.A. Ustynyuk, Professor of the Faculty of Chemistry, Moscow University
V.V. Lunina, corresponding member RAS, Dean of the Faculty of Chemistry, Moscow University

The jury of 19 people included representatives of Moscow, Yerevan and Belarusian State Universities, as well as a number of other chemical organizations in Moscow and Yerevan.

The jury of the Olympiad was headed by

• L.A. Sahakyan, Professor, Head of the Department of Chemistry, Yerevan State Medical University, Chairman of the Jury
• A.I. Zhirov, Associate Professor of the Faculty of Chemistry, Moscow University M.V. Lomonosov, Deputy jury chairman

All organizational concerns fell on the shoulders of a public organization " Olympic Movement Schoolchildren of Armenia" and the Association for Chemistry Education.
48 schoolchildren from Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia and Estonia took part in the Olympiad.
First theoretical tour was held in Tsakhkadzor in the House of Creativity of Writers of Armenia. In this round, students were offered to solve eight tasks in inorganic, organic and physical chemistry.

You can test your strength by trying to solve them yourself:

Second, experimental, tour passed in the laboratories of the Department of Chemistry of the Yerevan State Medical University after Mkhitar Heratsi. In Yerevan it was warm and sunny for everyone, both literally and figuratively.
The XXXII Mendeleev Olympiad is planned for May 1998 in Kyrgyzstan.
The winners of the Olympiad were awarded with Diplomas of I, II and III degrees

I degree diplomas received:

Diplomas of II degree received:
1. Druzhinin Sergey, Korolev, Moscow region, Russia
2. Anton Bogatyrev, Yekaterinburg, Russia
3. Verbitsky Dmitry, Baranovichi, Belarus
4. Zaitsev Alexander, Moscow, Russia
5. Piskunov Matvey, Vitebsk, Belarus
6. Agafontsev Alexander, Omsk, Russia
7. Alexander Romanenkov , Tula, Russia
8. Sizemskaya Valeria, Narva, Estonia
9. Oleg Vydrov, Minsk, Belarus
10. Rodionov Valentin, Moscow, Russia

The main goals and objectives of the sectoral Olympiad for schoolchildren is to identify gifted schoolchildren who are focused on engineering and technical specialties, capable of technical creativity and innovative thinking and planning their own professional activity in the gas industry.

The Olympics is being held educational organizations higher education among the leading universities Russian Federation jointly with PJSC Gazprom. The Chemistry Olympiad is held by the Russian State University of Oil and Gas (National Research University) named after I.M. Gubkin and Kazan National Research technological university. The face-to-face stages of the Olympiad are held at many regional venues.

This Olympiad is not a status Olympiad when entering universities. However, she provides unique opportunity test your strength before passing the exam, get necessary information about the conditions of study at the university, its winners are awarded with valuable prizes. The winners and prize-winners of the Olympiad will receive additional points for USE results, within the framework of accounting individual achievements applicant (up to 10 points).

The Olympiad is held in two stages:
- registration and the first (remote) stage - from 11/01/2017 to 01/10/2018;
- the second (final) stage is carried out in full-time during the period from February 1 to March 31, 2018. Winners and prize-winners of the first (qualifying) stage of the Olympiad are allowed to participate in it.
To get acquainted with examples of tasks and prepare for the qualifying round of the Olympiad, participants are invited to go through a preparatory round. Participation in it is not mandatory and the results are not taken into account in the future.

Russian University of Chemical Technology named after D.I. Mendeleev holds the Interregional Chemistry Olympiad named after academician P. D. Sarkisov for schoolchildren of grades 9-11...

The competition takes place in two stages. The qualifying round is held remotely. Completed tasks are checked with computer program and are not subject to appeal.

The final stage takes place in person at the university's sites in Moscow and the regions of Russia. Winners and prize-winners of the first stage are invited to it. When performing Olympiad tasks, the organizers allow the use of periodic system chemical elements by D. I. Mendeleev and the table of solubility and stress series of metals.

What's new

How to participate

1. Register for the Olympiad on the website of the organizers.
2. Complete the tasks of the qualifying stage. The results will be published on the website.
3. Choose a convenient venue for the full-time stage, register.
4. Complete the tasks of the final stage. Preliminary results will be published on the Olympiad website.
5. If you do not agree with the jury's assessment, file an appeal.
6. Look for the final results on the website of the organizers.

What's Special

How to prepare

Solve problems from previous years Deal with difficult passages with the teacher. Ask questions. The school is interested in your success - this increases its prestige.

Dear applicants!

In 2018-2019 on the basis of the Russian State University of Oil and Gas (National Research University) named after I.M. Gubkin will be held:

2. Interregional Olympiad for Schoolchildren in Chemistry named after Academician P.D. Sarkisova

Students of grades 10-11 are invited to participate in the Interregional Chemistry Olympiad for schoolchildren. The winners and prize-winners of the Olympiad receive 10 and 7 points, respectively, to the total USE score.

The organizers of the Olympiad are the Russian University of Chemical Technology named after D.I. Mendeleev and Russian State University oil and gas (national research university) named after I.M. Gubkin.

The Olympiad will be held in 2 stages: qualifying (on-line) and final (full-time). The qualifying stage (Internet tour) is held from November 10, 2018 to December 25, 2018 and includes tasks in chemistry. To participate in the qualifying stage, you must go through online registration on the site olimp.muctr.ru, which will be open from November 10, 2018. To do this, the participant activates his Personal Area by entering a login and password, fills in the unloaded and printed form of the questionnaire.

The final stage of the Interregional Chemistry Olympiad named after Academician P.D. Sarkisov will be held on March 3, 2019

You must have with you:

The passport;
- One 3x4 photo (color or black and white);
- Certificate of study from educational institution issued not earlier than September 1, 2018 (the certificate is transferred to the Organizing Committee and is not returned to the participant);
- Non-programmable (normal, non-engineering) calculator.

Winners and prize-winners of the qualifying stage, as well as winners and prize-winners of grades 9 and 10 of the Academician P.D. Sarkisov 2017/2018 academic year.

Regional venues for the Final Stage of the Interregional Chemistry Olympiad for schoolchildren named after Academician P.D. Sarkisov:

FGBOU VO "Russian University of Chemical Technology named after D.I. Mendeleev"

Address: Moscow, 1st Miusskaya street, 3

Russian State University of Oil and Gas (National Research University) named after I.M. Gubkin

Address: Moscow, Leninsky Prospekt, building 65
Start time: 10:00 (Moscow time).

Federal State Budgetary Educational Institution of Higher Education "Kemerovo Technological Institute" Food Industry(university)"

Address: Kemerovo, Builders Boulevard, 47

Federal State Budgetary Educational Institution of Higher Education "Altai State University"

Address: Barnaul, Lenina avenue, 61
Start time: 14:00 (local time).

MBOU " secondary school No. 144"

Address: Krasnoyarsk, street 40 years of Victory, house 24
Start time: 16:00 (local time).

3 . United Interuniversity Mathematical Olympiad

On the same site you can see the position and regulations of the Olympiad, as well as tasks from previous years.

Since 2009, an interuniversity olympiad in mathematics has been held for 11th graders on the initiative of a group of Moscow universities. Since 2009, OMMO has been included in the List of Olympiads of the Ministry of Education and Science of the Russian Federation, and its diplomas are officially taken into account when applying to universities.

In the List of the Olympiad 2018/19 academic year. OMMO-2019 has the second level. Decisions on benefits (admission without entrance examinations, and 100 points in a subject with a USE in mathematics (profile) of at least 75 points) are made by universities and must be announced within the time frame determined by the Ministry of Education and Science.

Participation in the Olympiad is voluntary and free of charge. published rules of conduct Olympics and calendar for participants.

The first round is scheduled for in absentia from December 25, 2018 - January 29, 2019 (registration will open at the same time).

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1 Materials of the Olympiad tasks of the qualifying stage of the Interregional Chemistry Olympiad for schoolchildren named after Academician P.D. Sarkisov grade 9 Option Write the reaction equations (indicating the conditions for their implementation), with the help of which transformations can be carried out: Сu Cu (OH) 2 Cu (NO 3) 2 CuCl 2. Each stage can be carried out in one or more stages. 2 Write the reaction equations (indicating the conditions for their implementation), with the help of which transformations can be carried out: Р РН 3 Ca 3 (PO 4) 2 CaHPO 4. Each stage can be carried out in one or several stages. 3. Indicate which of the listed oxides CO, Cr 2 O 3, CaO, NO 2, FeO interact with caustic soda. Write the appropriate equations chemical reactions. 4. Indicate which of the listed oxides CO, Cr 2 O 3, CaO, NO 2, Fe 3 O 4 interact with a dilute solution of sulfuric acid. Write the appropriate equations for chemical reactions. 5. Write an equation for the oxidation of hydrogen sulfide with potassium permanganate in a neutral medium. 6. Determine the mass of sulfur that can be obtained by passing hydrogen sulfide through 200 ml of 5 wt. % KMnO 4 solution (density 1.04 g/ml) in a neutral medium (see task 5). 7. For chlorination of 22.0 g of a mixture of powders of aluminum and iron, 20.16 liters (n.o.) of chlorine were required. Calculate the mass fraction of iron in the initial mixture. 8. Determine what volume of hydrogen (n.o.) can be obtained by dissolving 22.0 g of a mixture of metals (see task 7) in an excess of hydrochloric acid. 9. 16 g of sulfur oxide (VI) was dissolved in 184 ml of water. Determine the mass fraction of the substance in the resulting solution. 10. Calculate how many ml. 10 wt. % potassium hydroxide solution (density 1.09 g / ml) will be required to neutralize the solution in task 9.

Option 2 Write the reaction equations (indicating the conditions for their implementation), with the help of which transformations can be carried out: Zn K 2 ZnO 2 ZnCl 2 Zn (NO 3) 2 Zn. Each stage can be carried out in one or more stages. 2. Write the reaction equations (indicating the conditions for their implementation), with the help of which transformations can be carried out: Si SiH 4 SiO 2 SiF 4 K 2. Each stage can be carried out in one or more stages. 3. Indicate which of the listed substances Mg(OH) 2, Cl 2, AgNO 3, NaHCO 3, Si interact with caustic potash. Write the appropriate equations for chemical reactions. 4. Indicate which of the listed substances Mg(OH) 2, Cl 2, AgNO 3, NaHCO 3, Si interact with an aqueous solution of hydrochloric acid. Write the appropriate equations for chemical reactions. 5. Write an equation for the oxidation of potassium iodide with potassium permanganate in an alkaline medium. 6. Determine the mass of iodine that is formed when excess KI is added to 200 ml of 5 wt. % solution of KMnO 4 (density 1.04 g/ml) in an alkaline medium. 7. To dissolve 22.2 g of a mixture of aluminum and iron powders in an excess of hydrochloric acid, 13.44 liters (n.o.) of hydrogen were obtained. Calculate the mass fraction of iron in the initial mixture. 8. Determine what volume of hydrogen (n.o.) can be obtained by dissolving 22.2 g of a mixture of metals (in task 7) in an excess of alkali g of phosphorus (v) oxide was dissolved in 1787 ml hot water. Find the mass fraction of the solute in the resulting solution 10. Determine how many ml of 20 wt. % NaOH solution (density 1.22 g / ml) will be required to completely neutralize the solution obtained in task 9.

3 10 class Option The laboratory has aqueous solutions of caustic soda, aluminum nitrate, sodium carbonate and calcium chloride. Write the equations for the chemical reactions that can take place between these substances. 2. Write the equations of chemical reactions: a) Zn + NaOH + H 2 O; b) KClO 3 ; c) Ca (HCO 3) 2 + Ca (OH) 2; d) H 2 S + SO 2; e) Fe 3 O 4 + HCl (conc.). 3. Write the reaction equations that make it possible to carry out transformations: Na NaNO 3 NaCl Na 2 SO 4 Na 2 S. 4. Determine which two substances and under what conditions entered into chemical reactions, if they resulted in the following products (indicated without coefficients) .?+?->fe(oh) 3 + Ca(NO 3) 2 + SO 2 ;?+?->Ca(OH) 2 + H 2 O;?+?->Ag 2 S + H 2 S + NaNO 3 ;?+?->CaCl 2 + S + HCl;?+?->CuO + P 2 O 5 + NO 2; 5. 8.96 l of ammonia (N.O.) was dissolved in 100 ml of 18 wt.% solution of phosphoric acid (density 1.089 g/ml). Determine the composition (wt.%) of the resulting solution. 6. Not organic matter contains 6.33 wt.% hydrogen, 15.19 wt.% carbon, 17.72 wt.% nitrogen and 60.76 wt.% oxygen. In 200 g of a 7.9 wt.% aqueous solution of this substance was dissolved 8.96 l (N.O.) of hydrogen chloride. Determine the mass fractions (in%) of the substances in the resulting solution. 7. Using only inorganic reagents at the first stage, propose a method for producing propane from methane. Write the equations of chemical reactions and indicate the conditions for their implementation. 8. Write the equations of chemical reactions: a) C 6 H 5 NO 2 + Zn + HCl b) ClCH 2 COOH + NH 3; c) CH 3 CH \u003d CH CH 3 + KMnO 4 d) C 6 H 5 -CH 2 -CH 3 + Cl 2 Cu e) C 2 H 5 OH 200 C. hν; ; HO C 9. Write the reaction equations for the following transformations: calcium carbide benzene ethylbenzene benzoic acid methyl ester. Specify the conditions for their implementation. 10. Combustion of 560 ml (N.O.) of hydrocarbon produced 2.8 L (N.O.) carbon dioxide and 1.8 g of water. Determine the formula of a hydrocarbon, and name and draw its possible isomers. Calculate the relative density of hydrocarbon from oxygen.

Option 4 The laboratory has carbon monoxide (IV) and aqueous solutions of zinc chloride, caustic potash and silver nitrate. Write the equations for the chemical reactions that can take place between these substances. 2. Write the equations of chemical reactions and arrange the coefficients: a) Al + NaOH; b) KClO 3 fusion; c) H 2 S + KMnO 4 + H 2 O; d) SO 2 + Br 2 + KOH; e) K 2 CO 3 + CO 2 + H 2 O. 3. Write the equations of chemical reactions that allow transformations: Cu CuCl 2 CuO CuSO 4 Cu 2 (OH) 2 CO Determine which two substances and under what conditions entered into chemical reactions, if the following products are obtained as a result of them (indicated without coefficients).?+?->fe(oh) 3;?+?->K 2 SO 4 + O 2;? H 2 O;? +?->BaSO 4 + (NH 4) 2 SO 4;? +?->CH 3 -C (O) -CH 3 (acetone). 5. 8.4 L (N.O.) of hydrogen chloride was dissolved in 375 g of water. Calculate the mass fraction of hydrochloric acid (in%) in the resulting solution. How many ml of 20 wt.% sodium hydroxide solution (density 1.2 g/ml) will be required to completely neutralize the acid solution? 6. 10.8 g of an alloy of sodium and potassium was dissolved in 120 g of water. As a result, 4.48 L (n.o.s.) of gas was released. Calculate the mass fraction (in %) of sodium in the original alloy. Determine what volume of a 20 wt.% solution of sulfuric acid (density 1.14 g/ml) will be required to completely neutralize the resulting solution. 7. Using only inorganic reagents at the first stage, suggest a method for obtaining 1,3-butadiene from methane. Write the equations of chemical reactions and indicate the conditions for their implementation. 8. Write the equations of chemical reactions and indicate the conditions for their implementation: BUT 2 a) CH 3 C CH + OH; b) C 6 H 5 OH + Br 2; C Hg c) C 2 H 5 OH; d) HC CH + H HSO 2 O + ; 2 4 (conc.) H HNO 3 (razb.) e) CH 3 -CH 2 -CH 3., p 9. Write the reaction equations (indicating the conditions for their implementation) that allow the transformations: acetylene acetic acid methane Specify the conditions for carrying out these reactions. 10. An unknown organic substance reacts with metallic sodium, with caustic soda and with soda. Write the reaction equations that make it possible to obtain this compound in the laboratory if it contains 68.85 wt.% carbon, 4.92 wt.% hydrogen and 26.23 wt.% oxygen. MnO2

5 11 class Option Using sulfur, air and water, suggest a method for obtaining ammonium sulfate. Any equipment and catalysts are at your disposal. Write reaction equations indicating the conditions for their implementation. 2. Compare the strength of two acids HF and HI. Which one is stronger in aqueous solution and why? Explain the reason. 3. The BF 3 molecule is non-polar, the NF 3 molecule is polar. Explain the reason for this difference in the properties of these molecules. 4. Two test tubes without labels contain aqueous solutions of potassium sulfide and potassium sulfate. What reactions can be used to identify each of these substances? Write the equations for these reactions. 5. Write the reaction equations (indicating the conditions for their implementation), with the help of which the following transformation can be carried out: H 3 PO 4 PH When a mixture of powdered beryllium and magnesium was calcined in air, its mass increased by 2 times. Determine the mass fraction of beryllium in the initial mixture. 7. Suggest a method for producing acetic acid using only inorganic reagents at the first stage. Write reaction equations indicating the conditions for their implementation. 8. Write the reaction equations (indicating the conditions for their implementation), with the help of which the following transformations can be carried out: CaC 2 C 2 H 4 HO-CH 2 -CH 2 -OH. 9. Complete the left parts of the reaction equations, indicate the conditions for their implementation and arrange the coefficients: a) CH 4 + Na 2 CO 3; b) CH 2 \u003d CH 2 + KBr + H 2 O; c) CH 3 C SAg + NH 3 + H 2 O; d) CH 3 COONa + C 2 H 5 OH; e) CH 3 CHO + H 2 O + Cu. 10. Calculate the mass fraction of CaC 2 in technical calcium carbide, if from 1 ton of calcium carbide such an amount of acetylene was obtained that was required for the synthesis of 260 kg of benzene. The yield of benzene during its production from acetylene was 80%.

Option 6 Using limestone, air and water, propose a method for obtaining ammonium carbonate. Any equipment and catalysts are at your disposal. Write reaction equations indicating the conditions for their implementation. 2. Compare the strength of the two bases Fe(OH) 2 and Fe(OH) 3. Which one is stronger and why? Explain the reason. 3. Determine the structure of SO 2 and CO 2 molecules. Explain the reason for the difference in the structure of these molecules. Which of these molecules is polar and why? 4. Two unlabeled tubes contain crystalline sodium bicarbonate and its carbonate. What reactions can be used to identify each of these substances? Write the equations for these reactions. 5. Write the reaction equations (indicating the conditions for their implementation), with the help of which the following transformation can be carried out: KCl KClO When calcining a mixture of sodium and potassium bicarbonates, its mass decreased by one and a half times. Determine the mass fraction of sodium bicarbonate in the initial mixture. 7. Suggest a method for producing ethanol using only inorganic reagents. Write reaction equations indicating the conditions for their implementation. 8. Write the reaction equations (indicating the conditions for their implementation), with the help of which the following transformations can be carried out: C 2 H 5 OH CH 3 COOH NH 2 CH 2 COOH. 9. Complete the left parts of the reaction equations, indicate the conditions for their implementation and arrange the coefficients: a) ... [C 6 H 5 NH 3] + Cl; b) CH C-CH 3 + KBr + H 2 O; c) HCHO + H 2 O + Cu; d) CH 4 + AlCl 3; e) HO-CH 2 - CH 2 -OH + MnO 2 + KOH, 01 mole of unsaturated hydrocarbon discolors 32 g of a 10.0 wt.% solution of bromine in CC1 4. When this hydrocarbon is passed through an aqueous solution of sulfuric acid containing HgSO 4, formed organic compound having in the composition of 22.2 wt.% oxygen. Determine the structure of the initial hydrocarbon and write the equations of the mentioned reactions.

Option 7 Using water and potassium chloride, suggest a method for obtaining potassium perchlorate. Any equipment and catalysts are at your disposal. Write reaction equations indicating the conditions for their implementation. 2. There are two bases Sr(OH) 2 and Ba(OH) 2. Which of these bases is stronger? Explain why. 3. Determine the structure of the H 2 O and H 2 Te molecules. Explain why the angle between chemical bonds in the H 2 Te molecule is close to 90 o, and in the H 2 O molecule this angle is 104.5 o. 4. Two test tubes without labels contain aqueous solutions of magnesium chloride and zinc chloride. What reactions can be used to identify each of these substances? Write the equations for these reactions. 5. Write the reaction equations (indicating the conditions for their implementation), with the help of which the following transformations can be carried out: H 2 SiO 3 SiH As a result of the interaction of a mixture of powdered magnesium and calcium with an excess of chlorine, its mass increased by 3 times. Determine the mass fraction of magnesium in the initial mixture of metals. 7. Suggest a method for producing butane using only inorganic reagents at the first stage. Write reaction equations indicating the conditions for their implementation. 8. Write the reaction equations (indicating the conditions for their implementation), with which you can carry out the following transformations: C 2 H 6 C 2 H 5 OH C 2 H 5 OS 2 H Supplement the left parts of the reaction equations, indicate the conditions for their implementation and arrange the coefficients : a) C 6 H 5 NO 2 + H 2 O; b) CH 2 =CH-CH=CH 2 + H 2 + H 2 O; c) HC CH + Ca (OH) 2; d) C 2 H 5 OH + CO 2; e) CH 3 COOH + Ag. 10. The gas obtained by burning 1.68 l (n.o.) of saturated hydrocarbon completely reacted with 67.8 ml of 15 wt.% sodium hydroxide solution (the density of this solution is 1.18 g / cm 3). As a result of this reaction, sodium bicarbonate was obtained. Determine the molecular formula of the hydrocarbon.

Option 8 Using limestone, sodium chloride and water, suggest a method for producing bleach. Any equipment and catalysts are at your disposal. Write reaction equations indicating the conditions for their implementation. 2. Compare the strength of the two acids HClO and HIO. Which one is stronger in aqueous solution and why? Explain the reason. 3. In the series H 2 Te H 2 Se H 2 S, when going from H 2 Te to H 2 S, the boiling point of the compounds decreases monotonically. Explain why there is a sharp increase in the boiling point when going from hydrogen sulfide to water. 4. Two unlabeled tubes contain crystalline ammonium chloride and calcium chloride. What reactions can be used to identify each of these substances? Write the equations for these reactions. 5. Write the reaction equations (indicating the conditions for their implementation), with the help of which the following transformations can be carried out: NaCl NaHCO 3 Na 2 CO When a mixture of magnesium and calcium carbonates was calcined, its mass decreased by 2 times. Determine the mass fraction of magnesium carbonate in the initial mixture. 7. Suggest a method for the production of chlorobenzene using only inorganic reagents at the first stage. Write reaction equations indicating the conditions for their implementation. 8. Write the reaction equations (indicating the conditions for their implementation), with the help of which the following transformations can be carried out: CaC 2 C 2 H 2 CH 3 COOH. 9. Complete the left parts of the reaction equations, indicate the conditions for their implementation and arrange the coefficients: a) C 2 H 5 -O-C 2 H 5 + H 2 O; b) C 6 H 6 + H 2; c) C 2 H 5 NO 2 + H 2 O; d) C 2 H 6 + Na 2 CO 3; e) C 4 H 10 + NaBr. 10. Ester monobasic carboxylic acid and limit monohydric alcohol contains 32.0 wt.% oxygen. The ether was heated with an excess of aqueous sodium hydroxide solution. The alcohol formed as a result of hydrolysis was distilled off and heated with concentrated sulfuric acid. As a result, a gas with a relative hydrogen density of 14 was obtained. Determine the structure of the ester.

9 Criteria for evaluating the Olympiad tasks of the qualifying stage of the Interregional Chemistry Olympiad for schoolchildren named after Academician P.D. Sarkisova 11th grade. Task 1. The maximum score is 10 points. A method for obtaining the required substance is described. All reactions are given with coefficients and indicating the conditions for their implementation 10 points. A method for obtaining the required substance is described. All reactions are given with coefficients without specifying the conditions for their implementation 8 points. A method for obtaining the required substance is described. All reactions are given without coefficients and without specifying the conditions for their implementation. 6 points. Only some of the reactions used to obtain the desired substance are given with coefficients and conditions for their implementation of 4 points. Only some of the reactions used to obtain the required substance are given without coefficients and without specifying the conditions for their implementation. 2 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Task 2. The maximum score is 10 points. A substance (acid, base) is determined, which is stronger in an aqueous solution. Based on the radii of atoms (ions) and electrostatic concepts, an explanation of the nature of dissociation in a solution of 10 points is given. A substance (acid, base) is determined, which is stronger in an aqueous solution. On the basis of only the radii of atoms (ions), an explanation of the nature of dissociation in a solution of 5 points is given. A substance (acid, base) is determined, which is stronger in an aqueous solution. On the basis of only electrostatic concepts, an explanation of the nature of dissociation in a solution of 5 points is given. A substance (acid, base) is determined, which is stronger in an aqueous solution without explanation 2 points. Task 3. The maximum score is 10 points. The structure of molecules of given substances is determined. The properties of substances are described and an explanation is given using the theory of covalent bonds 10 points. The structure of molecules of given substances is given. The properties of substances are described without using the theory of covalent bonds 5 points. The properties of substances are described without determining the structure of molecules 5 points. Task 4. Maximum score 10 points. Both substances have been identified. Correctly written all the equations of chemical reactions with coefficients and indicating the conditions for their implementation 10 points. Both substances have been identified. All equations of chemical reactions are correctly written with coefficients without specifying the conditions for their implementation 8 points. Both substances have been identified. All equations of chemical reactions are correctly written without coefficients and without specifying the conditions for their implementation 6 points. One of the substances proposed for determination was determined; equations of chemical reactions are written with coefficients and indicating the conditions for their implementation 5 points. One of the substances proposed for determination was determined; the equations of chemical reactions are written without coefficients or without specifying the conditions for their implementation 3 points. One of the substances proposed for determination was determined without specifying the conditions for conducting reactions and without coefficients of 2 points.

10 One of the substances was identified without specifying the conditions for its implementation 2 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Task 5. The maximum score is 10 points. Correct writing all equations of the chain of chemical transformations with coefficients and indicating the conditions for their implementation 10 points. Correct writing of all equations of the chain of chemical transformations with coefficients, but without specifying the conditions for their implementation 8 points. Correct spelling of 4 equations 8 points. Writing all the equations of the chain of chemical transformations without coefficients and without specifying the conditions for their implementation 6 points. Correct spelling of two equations 4 points. Correct spelling of one equation 2 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Exercise. 6 Maximum score 10 points. Correctly solved problem with writing all reaction equations indicating the dimension of all used quantities 10 points. Correctly solved problem with writing all reaction equations with the absence of dimensions of the quantities used minus 2 points. A correctly solved problem without writing the equations of ongoing chemical reactions with the absence of dimensions of the quantities used minus 2 points. A correctly solved problem without writing the equations of ongoing chemical reactions with the absence of dimensions of the quantities used minus 4 points. Arithmetic error in the calculation of molar masses minus 5 points. Arithmetic error when converting one dimension to another minus 5 points. Correct move of the solution, but wrong answer as a result of other arithmetic errors minus 5 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Task 7. Maximum score 10 points. A method for obtaining the required substance is described. All reactions are given with coefficients and indicating the conditions for their implementation 10 points. A method for obtaining the required substance is described. All reactions are given with coefficients without specifying the conditions for their implementation 8 points. A method for obtaining the required substance is described. All reactions are given without coefficients and without specifying the conditions for their implementation. 6 points. Only some of the reactions used to obtain the desired substance are given with coefficients and conditions for their implementation of 4 points. Only some of the reactions used to obtain the required substance are given without coefficients and without specifying the conditions for their implementation. 2 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Task 8. Maximum score 10 points. Correct writing of all equations of the chain of chemical transformations with coefficients and indicating the conditions for their implementation 10 points. Correct writing of all equations of the chain of chemical transformations with coefficients, but without specifying the conditions for their implementation 8 points.

11 Correct spelling of 4 equations 8 points. Writing all the equations of the chain of chemical transformations without coefficients and without specifying the conditions for their implementation 6 points. Correct spelling of two equations 4 points. Correct spelling of one equation 2 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Task 9. Maximum score 10 points. Correct writing of all equations of chemical reactions with coefficients and indicating the conditions for their implementation 10 points. Correct writing of 4 equations of chemical reactions with coefficients and indicating the conditions for their implementation 8 points. Correct writing of 3 equations of chemical reactions with coefficients and indicating the conditions for their implementation 6 points. Correct writing of 2 equations of chemical reactions with coefficients and indicating the conditions for their implementation 4 points. Correct writing of one equation of chemical reactions with coefficients and indicating the conditions for their implementation 2 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Exercise. 10 Maximum score 10 points. Correctly solved problem with writing all reaction equations indicating the dimension of all used quantities 10 points. Correctly solved problem with writing all reaction equations with the absence of dimensions of the quantities used minus 2 points. A correctly solved problem without writing the equations of ongoing chemical reactions with the absence of dimensions of the quantities used minus 2 points. A correctly solved problem without writing the equations of ongoing chemical reactions with the absence of dimensions of the quantities used minus 4 points. Arithmetic error in the calculation of molar masses minus 5 points. Arithmetic error when converting one dimension to another minus 5 points. Correct move of the solution, but wrong answer as a result of other arithmetic errors minus 5 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. The total maximum score is 100 points. Grade 10. Task 1, 2, 4 and 8. The maximum score is 10 points. Correct writing of all equations of chemical reactions with coefficients and indicating the conditions for their implementation 10 points. Correct writing of 4 equations of chemical reactions with coefficients and indicating the conditions for their implementation 8 points. Correct writing of 3 equations of chemical reactions with coefficients and indicating the conditions for their implementation 6 points. Correct writing of 2 equations of chemical reactions with coefficients and indicating the conditions for their implementation 4 points. Correct writing of one equation of chemical reactions with coefficients and indicating the conditions for their implementation 2 points.

12 With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Task 3 and 9. Maximum score 10 points. Correct writing of all equations of the chain of chemical transformations with coefficients and indicating the conditions for their implementation 10 points. Correct writing of all equations of the chain of chemical transformations with coefficients without specifying the conditions for their implementation 7 points. Correct writing of all equations of the chain of chemical transformations without coefficients, indicating the conditions for their implementation 6 points. Correct spelling of four transformations with coefficients and indicating the conditions for its implementation 8 points. Correct spelling of three transformations with coefficients and indicating the conditions for its implementation 6 points. Correct spelling of two transformations with coefficients and indicating the conditions for its implementation 4 points. Correct spelling of one transformation with coefficients and indicating the conditions for its implementation 2 points. With the correct spelling of the reaction products, but errors in the coefficients, one point is taken off for each reaction. Task 5, 6 and 10. Maximum score 10 points. Correctly solved problem with writing all reaction equations indicating the dimension of all used quantities 10 points. Correctly solved problem with writing all reaction equations with the absence of dimensions of the quantities used minus 2 points. A correctly solved problem without writing the equations of the ongoing chemical reactions of the used values ​​minus 2 points. A correctly solved problem without writing the equations of ongoing chemical reactions with the absence of dimensions of the quantities used minus 4 points. The correct course of the solution, but the arithmetic error in the calculation of molar masses minus 5 points. The correct course of the solution, but an arithmetic error when converting one dimension to another minus 5 points. Correct move of the solution, but wrong answer as a result of other arithmetic errors minus 5 points. Task 7. Maximum score 10 points. A method for obtaining the required substance is described. All reactions are given with coefficients and indicating the conditions for their implementation 10 points. A method for obtaining the required substance is described. All reactions are given with coefficients without specifying the conditions for their implementation 8 points. A method for obtaining the required substance is described. All reactions are given without coefficients and without specifying the conditions for their implementation. 6 points. Only some of the reactions used to obtain the desired substance are given with coefficients and conditions for their implementation of 4 points. Only some of the reactions used to obtain the required substance are given without coefficients and without specifying the conditions for their implementation. 2 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. The total maximum score is 100 points.

13 9th grade. Task 1 and 2. The maximum score is 10 points. Correct writing of all equations of the chain of chemical transformations with coefficients and indicating the conditions for their implementation 10 points. Correct writing of all equations of the chain of chemical transformations with coefficients, but without specifying the conditions for their implementation 8 points. Correct spelling of 4 equations 8 points. Writing all the equations of the chain of chemical transformations without coefficients and without specifying the conditions for their implementation 6 points. Correct spelling of two equations 4 points. Correct spelling of one equation 2 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. Task 3 and 4. Maximum score 10 points. Correct writing of all equations of chemical reactions with coefficients and indicating the conditions for their implementation 10 points. Correct writing of all equations of chemical reactions with coefficients without specifying the conditions for their implementation 8 points. Correct writing of all equations of chemical reactions without coefficients and without specifying the conditions for their implementation 6 points. With the correct spelling of the reaction products, but errors in the coefficients (without specifying the conditions), one point is deducted for each reaction. With the correct spelling of the reaction products, but errors in the coefficients and without specifying the conditions, two points are deducted for each reaction. Task 5 Maximum score 10 points. Correct spelling of the equation of a chemical reaction with coefficients and with the preparation of an electronic balance, as well as indicating that the molecules of the medium do not participate as starting substances 10 points. Correct spelling of the chemical reaction equation with coefficients, but without electronic balance 8 points. Correct spelling of the chemical reaction equation without coefficients and without electronic balance 5 points. Task The maximum score is 10 points. Correctly solved problem with writing all reaction equations indicating the dimension of all used quantities 10 points. Correctly solved problem with writing all reaction equations with the absence of dimensions of the quantities used minus 2 points. A correctly solved problem without writing the equations of ongoing chemical reactions with the absence of dimensions of the quantities used minus 2 points. A correctly solved problem without writing the equations of ongoing chemical reactions with the absence of dimensions of the quantities used minus 4 points. The correct course of the solution, but the arithmetic error in the calculation of molar masses minus 5 points. The correct course of the solution, but an arithmetic error when converting one dimension to another minus 5 points. Correct move of the solution, but wrong answer as a result of other arithmetic errors minus 5 points. The total maximum score is 100 points.

14 Materials of the Olympiad tasks of the final stage of the Interregional Chemistry Olympiad for schoolchildren named after Academician P.D. Sarkisov Grade 9 Option Write five equations of various chemical reactions with which copper (II) oxide can be obtained in the laboratory, indicating the conditions for their implementation. 2. Write five equations for various chemical reactions that can be used to obtain sulfur (IV) oxide in the laboratory, indicating the conditions for their implementation. 3. There are aqueous solutions of sodium sulfide and sodium sulfate in unlabeled jars in the laboratory. Suggest methods for determining each substance and the presence of all ions in these solutions. Write the appropriate equations for chemical reactions. 4. The following substances are available in the chemical laboratory: Cl 2, CO 2 and NaOH. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 5. In an aqueous solution, the interaction of AlCl 3 with Na 2 S fails to obtain aluminum sulfide. Explain why. How to get aluminum sulfide? Write the equations for the corresponding chemical reactions. 6. Write the equations of chemical reactions: Zn + NaOH + H 2 O; Ca(HCO 3) 2 + NaOH; Fe 3 O 4 + HCl(conc.) ; ; Al(NO 3) 3 KI (crystal) + H 2 SO 4 (conc.). 7. Write the reaction equations that make it possible to carry out transformations indicating the conditions for their implementation: Na 2 SO 4 NaNO 3 NaCl Na 2 S. 8. An unknown substance precipitated when pouring aqueous solutions of potassium carbonate and copper nitrate. Establish the formula of this substance if, after calcination, its mass decreased by 1.3875 times, and gas and water were released. Write the equations for the corresponding chemical reactions. 9. The inorganic material contains 6.33 wt% hydrogen, 15.19 wt% carbon, 17.72 wt% nitrogen, and 60.76 wt% oxygen. Determine chemical formula this substance. How does it decompose when heated? Write the equation for the ongoing chemical reaction. 10. 212.4 ml of 14 wt% calcium chloride solution (density 1.12 g/ml) and 369 g of 20 wt% sodium phosphate solution were mixed. Calculate the mass of the precipitate formed and the mass fraction of salts in the resulting solution

15 Option Write five equations for various chemical reactions that can be used to obtain magnesium oxide in the laboratory, indicating the conditions for their implementation. 2. Write five equations for various chemical reactions that can be used to obtain carbon monoxide (IV), indicating the conditions for their implementation. 3. There are aqueous solutions of magnesium and aluminum sulfates in unlabeled jars in the laboratory. Suggest methods for determining each substance and the presence of all ions in these solutions. Write the appropriate equations for chemical reactions. 4. In the chemical laboratory there are the following substances: H 2 S, KOH and SO 2. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 5. Two unlabeled tubes contain crystalline potassium bicarbonate and its carbonate. What reactions can be used to identify each of these substances and all its cations and anions? Write the equations for these reactions. 6. Write the equations of chemical reactions: K 2 + H 2 SO 4 (excess); Ca(HCO 3) 2 + KOH; H 2 O 2 + KMnO 4 + H 2 O; Hg(NO 3) 2 KH 2 PO 4;. 7. Write the reaction equations that make it possible to carry out transformations indicating the conditions for their implementation: Ca Ca (HCO 3) 2 CaCO 3 CaOCl As a result of prolonged calcination in air of a mixture of powdered magnesium and its hydroxide, the mass of this mixture did not change. Calculate the mass fraction of magnesium in the initial mixture. 9. The inorganic substance contains 5.0 wt.% hydrogen, 35.0 wt.% nitrogen and 60.0 wt.% oxygen. Determine the chemical formula of this substance. How, depending on the conditions, does it decompose when heated? Write the equations of the chemical reactions that take place in this case. 10. 50 g of sulfuric anhydride was dissolved in 200 ml of water. Calculate the mass fraction of the substance in the resulting solution. How many grams of caustic potash will be required to completely neutralize this solution? Determine the mass of salt that is in the sediment, if it saturated solution contains 10.0 wt.% of the substance.

16 Grade 10 Option Explain why chlorine exhibits odd valences in most of its compounds. Draw the graphical formulas of the molecules of oxygen acids of chlorine. Which of these acids is the strongest? Give an explanation. 2. The laboratory has aqueous solutions of sodium hydroxide, aluminum chloride, sodium carbonate and calcium chloride. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 3. Write the equations of chemical reactions: ; a) MgHPO 4 b) Na + H 2 SO 4 (excess); c) H 2 S + KMnO 4 + H 2 O; d) Fe 3 O 4 + HNO 3 (conc.). e) Hydrolysis of CuSO 4 ; 4. Write the reaction equations for the transformations: K KHCO 3 KNO 3 KCl K 2 S. 5. 8.96 l of ammonia (n.o.) was dissolved in 100 ml of 18 wt.% orthophosphoric acid solution (density 1.089 g / ml ). Determine the composition (wt.%) of the resulting solution. 6. The inorganic matter contains 6.33 wt.% hydrogen, 15.19 wt.% carbon, 17.72 wt.% nitrogen and 60.76 wt.% oxygen. In 200 g of a 7.9 wt.% aqueous solution of this substance was dissolved 8.96 l (N.O.) of hydrogen chloride. Determine the mass fractions (in%) of the substances in the resulting solution. 7. Using only inorganic reagents, suggest a method for producing propane from methane. Write the equations of chemical reactions and indicate the conditions for their implementation. 8. Write the equations of chemical reactions: a) C 6 H 5 NO 2 + Zn + HCl b) ClCH 2 COOH + NH 3; c) CH 3 CH \u003d CH CH 3 + KMnO 4 d) C 6 H 5 -CH 2 -CH 3 + Cl 2 Cu e) c 2 H 5 OH 200 C. hν; ; HO C 9. Write the equations of the reactions that make it possible to carry out the transformations: calcium carbide benzene ethylbenzene benzoic acid methyl ester 10. Combustion of 560 ml of vapor (n.o.) 8 g of water. Determine the formula of a hydrocarbon and name its possible isomers. Calculate the relative vapor density of this hydrocarbon from oxygen.

Option 17 Write five equations for the chemical reactions of thermal decomposition. inorganic substances that proceed without changing the oxidation states of their constituent elements? 2. The laboratory contains chlorine, iron, sulphuric acid and sulfur. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 3. Write the equations of chemical reactions: a) Al + KMnO 4 + KOH; b) KHSO 3 ; c) Hydrolysis of Fe 2 (SO 4) 3; d) С1 2 + Ba(OH) 2 ; e) H 2 S + SO 2;. 4. Write the equations of the reactions that make it possible to carry out transformations: P. PH 3 P 2 O 5 Ca 3 (PO 4) 2 CaHPO As a result of dehydration of sodium sulfite crystalline hydrate, its mass decreased by 2 times. Set the formula of this crystalline hydrate. Write the reaction equation for the interaction of sodium sulfite with potassium permanganate in a neutral medium. 6. A mixture of calcium and calcium carbide was treated with an excess of mineral acid. The resulting gases reacted with each other without residue over a heated catalyst to form a substance whose oxygen density is 0.9375. Calculate the mass fraction of calcium in the initial mixture. 7. Using only inorganic reagents, suggest a method for obtaining acetic acid ethyl ester. Write the equations of chemical reactions and indicate the conditions for their implementation. 8. Write the equations of chemical reactions: HgSO4 a) CH 3 C C CH 3 + H 2 O; H + b) CH 3 OH + KMnO 4 + H 2 SO 4; c) NH 2 CH 2 COONa + HCl (wt); KOH d) C 3 H 7 Cl; alcohol, e) CH 2 \u003d CH CH 3 + KMnO 4 + H 2 SO Write the equations of the reactions that make it possible to carry out transformations: propanoic acid ethane ethylene ethylene glycol. 10. During the combustion of 1.7 g of hydrocarbon, the vapor density of which in terms of oxygen is 2.125, 2.8 l (n.o.) of carbon dioxide and 1.8 g of water were obtained. Determine the formula of a hydrocarbon and draw possible graphical formulas for its isomers.

Option 18 Aqueous solutions of caustic potash, zinc nitrate, sodium carbonate and calcium chloride are available in the laboratory. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 2. Write five equations for chemical reactions of thermal decomposition of nitric acid salts. Which of these reactions should be carried out in a fume hood and why? 3. Write the equations of chemical reactions: a) KI + KMnO 4 + KOH; b) KHSO 4 ; c) Hydrolysis of BaS; d) Al + KOH (fusion); e) FeO + HNO 3 (conc.). 4. Write the reaction equations that allow the transformations: H 2 S S SO 2 H 2 SO 4 S. 5. 5.6 l of sulfur oxide (IV) (n.o.) was dissolved in 115 ml of 8 wt.% sodium hydroxide solution ( density 1.087 g/ml). Determine the mass fractions of substances (in%) in the resulting solution, 8 g of an alloy of sodium and potassium was dissolved in 120 g of water. As a result, 4.48 L (n.o.s.) of gas was released. Calculate the mass fraction (in %) of sodium in the original alloy. Determine what volume of a 20 wt.% solution of sulfuric acid (density 1.14 g/ml) will be required to completely neutralize the resulting solution. 7. Using only inorganic reagents, suggest a method for producing ethylene glycol. Write the equations of chemical reactions and indicate the conditions for their implementation. 8. Write the equations of chemical reactions: a) C 2 H 5 C CH + H 2 O; HgSO H 4 + b) C 2 H 5 OH + KMnO 4 + H 2 SO 4; c) CH 3 CH 2 C CH + OH; HO 2 d) C 6 H 5 NH 2 + Br 2; e) C 6 H 5 COOK + KOH (solid). 9. Write the reaction equations that make it possible to carry out transformations: calcium carbide benzene ethylbenzene potassium benzoate. 10. When processing 8.35 g of a mixture of phenol and limiting monohydric alcohol with an excess alkali metal 1.4 l (n.o.) of gas is released, when the same amount of the mixture is treated with an excess of bromine water, 8.275 g of precipitate precipitates. Determine the formula of alcohol and its mass and mole fraction in the initial mixture (in %).

19 Variant Aqueous solutions of silver nitrate, caustic potash, aluminum chloride and sodium carbonate are available in the laboratory. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 2. Write five equations for the chemical reactions of the thermal decomposition of ammonium salts that proceed without changing the oxidation states of their constituent atoms. 3. Write the equations of chemical reactions: ; a) Hg (NO 3) 2 b) Si + KOH (fusion); c) Hydrolysis of Fe 2 (SO 4) 3; d) Al 2 O 3 + Na 2 CO 3 fusion e) FeSO 4 + K 2 Cr 2 O 7 + H 2 SO 4. ; 4. Write the equations of the reactions that make it possible to carry out the transformations: Al. Al (OH) 3 Al (NO 3) 3 Al 2 O 3 KAlO When a mixture of iron and aluminum is treated with an excess of an aqueous solution of alkali, two times less hydrogen is released than when this mixture is dissolved in an excess of hydrochloric acid. Determine the mass fraction of iron in the mixture of metals under consideration. 6. Determine what volume of 100 wt.% sulfuric acid (density 1.84 g / ml) must be dissolved in 250 ml of a 20 wt.% solution of H 2 SO 4 (density 1.14 g / ml) to obtain 75 wt. % solution of H 2 SO Using only inorganic reagents, propose a method for obtaining toluene. Write the equations of chemical reactions and indicate the conditions for their implementation. 8. Write the equations of chemical reactions: a) C 2 H 5 OH + KMnO 4 + H 2 SO 4; b) C 3 H 7 COONa + NaOH (solid) c) CH 3 CH \u003d CH 2 + KMnO 4 d) C 6 H 5 NH 2 + H 2 SO 4; e) CH 3 C C CH 3 + H 2 O HO C; ; HgSO H Write the equations of the reactions that make it possible to carry out the transformations: benzoic acid benzene aniline 2,4,6-tribromaniline. 10. An unknown organic substance reacts with metallic sodium, with caustic soda and with soda. Write the reaction equations that make it possible to obtain this compound in the laboratory if it contains 68.85 wt.% carbon, 4.92 wt.% hydrogen and 26.23 wt.% oxygen.

20 Grade 11 Option Explain why phosphorus (V) fluoride exists and a similar nitrogen fluoride has not been obtained. What is the valency of nitrogen in a nitric acid molecule? Draw a graphical formula for the nitric acid molecule. 2. The chemical laboratory has distilled water and crystalline substances: Al, NaOH, K 2 HPO 4. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 3. Salts of which acids are thermally unstable and easily decompose when heated? Write five equations for chemical reactions of thermal decomposition of various salts, which are accompanied by a change in the oxidation states of their constituent elements. 4. What two substances entered into a chemical reaction and under what conditions, if the following products were obtained as a result of it (indicated without coefficients).? +?->KIO 3 + Cl 2? +?-> CaSO 4 + (NH 4) 2 SO 4 + CO 2 + H 2 O;? +?-> Fe (OH) 3 + Ca (NO 3) 2 + SO 2;? +?-> CaCl 2 + S + HCl;? +?->Cu 3 (PO 4) 2 + CuO + NO 2; Write the equations of these reactions indicating the conditions for their implementation, 6 g of iron oxide Fe 3 O 4 was dissolved in 160 ml of a 36 wt.% solution of hydrochloric acid (density 1.1775 g / ml). Calculate the mass fraction of substances in the resulting solution. 6. When an aqueous solution of substance A is evaporated, crystals of substance B precipitate. When substance B is calcined, its mass decreases by 1.5625 times and substance A is obtained. When sodium carbonate solution is added to a solution of substance A, a precipitate of substance C precipitates. When substance C is calcined, substance C is obtained G is black, the molar mass of which is half the molar mass of substance A. In this case, gas D and water are released. Determine the formulas of substances A, B, C, D, E and write the equations of all chemical reactions. 7. Write five equations of chemical reactions, as a result of which ethyl alcohol is formed, indicating the conditions for their implementation. 8. Write the equations of chemical reactions: hν C 6 H 5 -CH 2 -CH 3 + Cl 2; CH 3 CH 2 -C CH + OH; C2H5OH; C HSO 2 4 (conc.) CH 3 -CH 2 -C CH + H 2 O HgSO4 + ; CH 3 -CH=CH-CH 3 +KMnO 4 +H 2 O H. HO C 9. Write the reaction equations that make it possible to carry out the transformations, indicating the P conditions for their implementation: cyclopropane 1-bromopropane toluene sodium benzoate. 10. The vapor density of a mixture of two isomeric hydrocarbons that do not have cis- and trans-isomers is equal to the density of a mixture of neon and krypton containing 21.875 vol.% neon. 10.5 g of this mixture were reacted with HBr to give 15.1 g of the corresponding monobromo derivative. Determine the structure of the isomeric hydrocarbons under consideration, the mass fraction (in%) of each in the initial mixture and its nitrogen density.

21 Choice Which acid is the strongest in an aqueous solution of HF, HCl or HBr? Explain why the acid properties change most sharply when going from HF to HCl? 2. In the chemical laboratory there are the following substances: KOH, SO 2 and Cl 2. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 3. Salts of which acids are thermally unstable and easily decompose when heated? Write five equations for chemical reactions of thermal decomposition of various salts that occur without changing the oxidation states of their constituent elements. 4. What two substances entered into a chemical reaction and under what conditions, if the following products were obtained as a result of it (indicated without coefficients).?+?->ag 2 S + H 2 S + NaNO 3 ;?+?->Ca( OH) 2 + H 2 O;? +?-> KCl + P 2 O 5;? +?->NaCl + S + SO 2 + H 2 O;?+?->Cr(OH) 3; Write the equations for these reactions, indicating the conditions for their implementation, 6 l (n.o.) of carbon dioxide reacted with 440 ml of 8 wt.% ammonia solution (density 0.96591 g/ml). Calculate the mass fraction of substances in the resulting solution. 6. When a yellow substance A is calcined, its mass is halved, and water and two nitrogen-containing gaseous compounds B and C are released. The molar mass of the green substance G obtained after calcination is molar mass starting substance A. Determine substances A, B, C and D if, when dilute sulfuric acid is added to a yellow aqueous solution of substance A, the color of the solution changes to orange, and the oxidation of substance B without a catalyst leads to the formation of substance C. Write the equations of all chemical reactions. 7. Write five equations of chemical reactions that form acetic acid, indicating the conditions for their implementation. 8. Write the equations of chemical reactions: Cu C 2 H 5 OH + CuO; 200 C HO 2 C 6 H 5 OH + Br 2 C 2 H 5 OH; 140 C HSO ; 2 4(conc.); HgSO + H CH 3 -C C-CH 3 + H 2 O 4 C 6 H 5 CH 2 CH 3 + KMnO 4 + H 2 SO 4; 9. Write the reaction equations that make it possible to carry out transformations, indicating the conditions for their implementation: 2-bromopropane propene Na benzene hexachlorocyclohexane. 10. Phenol, obtained from the acid-catalyzed hydrolysis of 15.9 g of the ester of the homologue of benzoic acid, forms 21.1 g of a precipitate upon treatment with excess bromine water. Determine the structure of the ester if it is known that the yield of the ester hydrolysis reaction is 85%.

22 Variant Ferric and aluminum sulfates interact differently in aqueous solutions with potassium sulfide. Write the equations for these reactions and explain the reason for their difference. 2. Crystalline aluminum sulfate, sodium carbonate, barium chloride and water are available in the laboratory. Write the maximum possible number of equations for chemical reactions that can occur between these substances. 3. Salts of nitric acid decompose when heated. Write five equations for the reactions of thermal decomposition of nitrates, in which products of various nature are formed. 4. What two substances entered into a chemical reaction and under what conditions, if the following products were obtained as a result of it (indicated without coefficients).? +? Ba (OH) 2 + H 2 O;? +? KCl + P 2 O 5;? +? K 2 SO 4 + S + SO 2 + H 2 O;? +? BaCl2 + S + HCl;? +? Cr (OH) 3 + Mg (NO 3) 2 + SO 2. Write the equations of these reactions indicating the conditions for their implementation, 6 g of iron oxide Fe 3 O 4 was dissolved in 160 ml of 36 wt.% solution of hydrochloric acid (density 1.1775 g/ml). Calculate the mass fraction of substances in the resulting solution. 6. The inorganic material contains 5.263 wt% hydrogen, 18.421 wt% nitrogen, 34.211 wt% chromium, and 42.105 wt% oxygen. Determine the chemical formula of this substance. How does it decompose when heated? Write an equation for the chemical reaction that takes place. 7. Write five equations of chemical reactions, as a result of which methyl alcohol is formed, indicating the conditions for their implementation. 8. Write the equations of chemical reactions: C 6 H 5 C 2 H 5 + KMnO 4 + H 2 O C 2 H 5 COONa + NaOH (solid) C 3 H 7 OH; C HSO 2 4 (conc.) HgSO + H CH 3 -CH 2 -C CH + H 2 O 4; ; CH 3 -CH=CH-CH 3 +KMnO 4 +H 2 O. HO C 9. Write the reaction equations that make it possible to carry out transformations, indicating the conditions for their implementation: carbon benzene ethylbenzene ethyl ester of benzoic acid. 10. For the complete hydrolysis of 45 g of a phenol ester and a limiting monobasic carboxylic acid, 200 ml of a 15 wt.% solution of caustic potash (density 1.12 g/ml) was required. Determine the structure of the initial ether and calculate the mass fractions of substances in the solution obtained after hydrolysis.

23 Variant In an aqueous solution, it is not possible to obtain iron (III) sulfide by carrying out the exchange reaction. Explain why. What reactions take place: a) when a solution of sodium sulfide is added to a solution of iron sulfate (III); b) when adding a solution of iron (III) sulfate to a solution of sodium sulfide? Write the equations for the corresponding chemical reactions. 2. In the chemical laboratory there are the following substances: KOH, SO 2 and Cl 2. Write the maximum possible number of equations of chemical reactions that can be carried out using these substances and indicate the conditions for their implementation. 3. Ammonium salts are thermally unstable and easily decompose when heated. Write five equations for chemical reactions of thermal decomposition of various ammonium salts, which are accompanied by a change in the oxidation states of their constituent elements. 4. What two substances entered into a chemical reaction and under what conditions, if the following products were obtained as a result of it (indicated without coefficients).? +? BaSO 4 + (NH 4) 2 SO 4 + CO 2 + H 2 O;? +? Cr(OH)3;? +? Zn 3 (PO 4) 2 + ZnO + NO 2;? +? KNO 3 + Ag 2 S + H 2 S;? +? KIO 3 + Cl 2. Write the equations of these reactions indicating the conditions for their implementation. 5. Salt of oxygen acid of phosphorus contains 19.167 wt.% sodium, 1.667 wt.% hydrogen and 53.333 wt. % oxygen. Determine the chemical formula of this substance. How does it decompose when heated? Write an equation for the chemical reaction that takes place. 6. After calcining a mixture of bicarbonate and sodium carbonate in air, it was found that the mass of this mixture decreased by 1.44 times. Determine the mass fraction of sodium bicarbonate (in%) in the initial mixture. 7. Write five equations of chemical reactions that ethanol can enter into, indicating the conditions for their implementation. 8. Write the equations of chemical reactions: HO 2 CH 3 -CH \u003d CH 2 + KMnO 4 + H 2 O; 0-20 C NH 2 CH 2 COOK + H 2 SO 4 (w) ; CH 3 C CH + OH; C 2 H 5 COONa + NaOH (solid) ; C 6 H 5 CH 3 + KMnO 4 + H 2 O. 9. Write the reaction equations that make it possible to carry out transformations, indicating the conditions for their implementation: carbon acetylene .. acetic acid chloroacetic acid. 10. It took 12 g of NaOH to neutralize the mixture of phenol and acetic acid. Treatment of the same amount of the mixture with an excess of sodium carbonate results in the release of 4.4 g (n.o.) of gas. Determine the mass fraction of phenol (in%) in the initial mixture of substances.

18 Key to option 1 Write the reaction equations corresponding to the following sequences of chemical transformations: 1. Si SiH 4 SiО 2 H 2 SiО 3 ; 2. Cu. Cu (OH) 2 Cu (NO 3) 2 Cu 2 (OH) 2 CO 3; 3. Methane

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CODE Part 1 Part 2 С1 С2 С3 С4 С5 С6 Final score (out of 100 points) Introductory work for applicants to 10 FH and HB classes Part 1 Circle the number of one correct answer with a circle. With the correct answer

Summer assignments in chemistry: 1. What chemical amount of CO 2 substance contains as many oxygen atoms as there are in 160 g of SO 3 substance? 2. What is the chemical amount of substance CH 4 contains

1. Which of the following elements is the most typical non-metal? 1) Oxygen 2) Sulfur 3) Selenium 4) Tellurium 2. Which of the following elements has the highest electronegativity? 1) Sodium

1. What reaction corresponds to the brief ionic equation H + + OH - \u003d H 2 O? 1) ZnCl 2 + 2NaOH = Zn(OH) 2 + 2NaCl, 2) H 2 SO 4 + CuSO 4 = CuSO 4 + 2H 2 O, 3) NaOH + HNO 3 = NaNO 3 + H 2 O 4) H 2 SO four

Chemical properties of salts (medium) QUESTION 12 Salts are complex substances consisting of metal atoms and acid residues Examples: Na 2 CO 3 sodium carbonate; FeCl 3 iron (III) chloride; Al 2 (SO 4) 3

18. Ionic reactions in solutions Electrolytic dissociation. Electrolytic dissociation is the breakdown of molecules in solution to form positively and negatively charged ions. The extent of decay depends

4.3 Tasks of the Internet tour (second wave) The Internet tour was held on-line using the electronic platform http://ege.psu.ru of the Perm State National Research University.

26 Key to option 1 1. Write the electronic formulas of aluminum and sulfur atoms. Determine the oxidation states of the sulfur atom in the following compounds: A1 2 S 3, A1 2 (SO 4) 3, Na 2 SO 3, Na 2 S 2 O 3, S 8. Al:

Grade 10 1. Determine the volume (in liters) of 35.0 g of ethylene at n.o.s. 2. Determine the serial number of a chemical element if the density of its gaseous oxide coincides with the density of nitrogen. Answer enter

TASK 3 Examples of problem solving Example 1. Four unlabeled test tubes contain solutions of the following substances: sodium sulfate, sodium carbonate, sodium nitrate and sodium iodide. Show with what

Chemistry test Grade 11 ( a basic level of) Test "Types of chemical reactions (chemistry grade 11, basic level) Option 1 1. Complete the reaction equations and indicate their type: a) Al 2 O 3 + HCl, b) Na 2 O + H 2 O,

Grade 10 Option 10-3 1. Explain why chlorine exhibits odd valencies in most of its compounds. Draw the graphic formulas of the molecules of the existing oxy-acids of chlorine. Which of these

Collection of problems in chemistry for 9 medical grade compiler Gromchenko I.A. Moscow Education Center 109 2012 Mass fraction of the dissolved substance. 1. 250 g of solution contains 50 g of sodium chloride. Determine

Option 4 1. What type of salts can be attributed to: a) 2 CO 3, b) FeNH 4 (SO 4) 2 12H 2 O, crystalline hydrate, c) NH 4 HSO 4? Answer: a) 2 CO 3 basic salt, b) FeNH 4 (SO 4) 2 12H 2 O double

Repetition of A9 and A10 (properties of oxides and hydroxides); A11 Characteristic Chemical properties salts: medium, acidic, basic; complex (on the example of aluminum and zinc compounds) A12 The relationship of inorganic

1 Olympiad "Lomonosov-2007" Option 1 1. Write one equation for reactions in which chlorine gas is: 2. Write the equation for the reaction that occurs when 0.2 mol of nitric acid is added to 0.1 mol

Bank of tasks 11th grade chemistry 1. The electronic configuration corresponds to the ion: 2. The particles and and and and have the same configuration 3. The magnesium and

Option 11-1 1. Calculate the mass (in grams) of 26.6 NL of silane. Enter your answer as a whole number without specifying the dimension. 2. The mass fraction of divalent metal in its sulfate is 40%. Determine

Instructions for the work: CHEMISTRY 3 hours (180 minutes) are given for the examination work in chemistry. The work consists of 2 parts and includes 35 tasks. Part 1 includes 20 tasks (A1 A20). To everyone

1. What is the charge of the nucleus of a carbon atom? 1) 0 2) +6 3) +12 4) -1 2. What do atoms 12 6C and 11 6C have in common? 1) Mass number 2) Number of protons 3) Number of neutrons 4) Radioactive properties Entrance tests for

1. Which of the following statements is true for saturated solutions? 1) a saturated solution can be concentrated, 2) a saturated solution can be diluted, 3) a saturated solution cannot

Class 9 tasks 1. Nitrogen shows a positive oxidation state in the compound: 1. NO 3. Na 3 N 2. NH 3 4. N 2 H 4 2. Metallic sodium does not react with: 1. HCl 2. O 2 3. To the main oxides include:

CONTROL MATERIALS FOR THE DISCIPLINE "CHEMICAL AND PHYSICO-CHEMICAL METHODS OF ANALYSIS OF NUCLEAR MATERIALS" INPUT CONTROL Questions of input control in the form of tests are intended to assess basic knowledge

Conditions for the tasks of the qualifying stage (online tour) of the Open Chemistry Olympiad 2016/2017 academic year Qualifying stage. Online tour. Grade 9 Terms. Task 1.1. The mass of an atom of element X is 1.66 10-24

Control test for applicants to the 10th physical and chemical class (chemical specialization), 2013 ANSWERS (highlighted in bold) Part 1 A1. What is the formula of the highest oxide of the element, electronic configuration

Salts Definition Salts are complex substances formed by a metal atom and an acid residue. Classification of salts 1. Medium salts, consist of metal atoms and acidic residues: NaCl sodium chloride. 2. Sour

Russian University of Chemical Technology DI. Mendeleev Qualifying (correspondence) stage of the All-Russian Chemistry Olympiad for schoolchildren Step into the future Option 1 1. As a result of calcining a mixture of carbonate

Topic ELECTROLYTIC DISSOCIATION. ION EXCHANGE REACTIONS Content element to be tested Task form Max. score 1. Electrolytes and non-electrolytes VO 1 2. Electrolytic dissociation of VO 1 3. Conditions for irreversible

Option 3 2 1. XO 4 ion contains 50 electrons. Determine the unknown element and write the interaction equation X in the form a simple substance with hot concentrated nitric acid. (6 points) Solution.

C1 Chemistry. Grade 11. Variant XI1060 1 Evaluation criteria for tasks with a detailed answer Using the electronic balance method, write the reaction equation: Cu 2 O + = SO 2 + + H 2 O Determine the oxidizing agent

1. The main properties are exhibited by the external oxide of the element: 1) sulfur 2) nitrogen 3) barium 4) carbon 2. Which of the formulas corresponds to the expression of the degree of dissociation of electrolytes: =

Grade 9 1. During the dissociation of 1 mol of what substances is formed the largest number(in moles) ions? 1. Sodium sulfate 2. Iron (III) chloride 3. Sodium phosphate 4. Cobalt (II) nitrate

REDOX PROCESSES OF THE BASIS OF ELETROCHEMISTRY the correct answer is underlined) 1 Which substances are strong reducing agents: A) manganese oxide IV), carbon monoxide IV) and silicon oxide IV);

Option 10-1 1. Determine the volume (in liters) of 28.849 g of phosphine at N.C. Enter your answer as a whole number without specifying the dimension. 2. Determine the ordinal number of the element whose mass fraction in its oxide is

2016 1. 4.2 g of lithium was dissolved in 250 ml of water, then 200 g of a 20% solution of copper(ii) sulfate was added. Determine the mass fraction of salt in the resulting In response, write down the reaction equations that are indicated in

Test (solution) Add 1. Chemical element A type of atom with the same nuclear charge. 2. A mole is the amount of a substance containing as many particles as there are atoms in 12 grams of carbon (12

MKOU HMR SOSH with. Elizarov compounds of NITROGEN Chemistry teacher: Kasyanova I.A. Nitrogen forms several strong compounds with hydrogen, of which ammonia is the most important. Electronic formula of the ammonia molecule

TASKS for the 2nd stage of the Olympiad "First steps in medicine" in chemistry Full name CLASS SCHOOL ADDRESS, TELEPHONE Option 4 (60 points) Part 1 (12 points) When completing the tasks of this part in the answer form 1 under the number

Training option examination work to prepare for the GIA for students in grade 9. Rudnichenko G.N., teacher of chemistry, secondary school 5 of the Kopeysk urban district of the Chelyabinsk region Purpose: to introduce students

Questions for intermediate certification in chemistry in grades 8-9 for the 2012-2013 academic year Textbook G.E. Rudzitis, F.G. Feldman "Chemistry Grade 8", "Chemistry Grade 9" Moscow 2009 1. Periodic law and periodic

Chemistry Olympiad, option 1 for the following molecules: NH 3, C 2 H 4. Rb 2 HPO 4, K 2 SO 3. Indicate a weak electrolyte or dissociation stage corresponding to c) Write the equations of hydrolysis processes: A1

Olympiad for schoolchildren "Conquer Sparrow Hills!" Chemistry Full-time tour Year 01 1. Calculate the mass of seven phosphorus atoms. M (P) 31 m 7 7 = 3.0 10 g. N 3 A.010 Answer: 3.0 10 g. ROSTOV Option 11. Gas mixture

Keys to the Olympiad tasks of the final stage of the Interregional Chemistry Olympiad for schoolchildren named after Academician P.D. Sarkisov Grade 9 Option 9-3 When checking the work, the score was reduced if not indicated

short information on conducting a verification work in chemistry of the 9th grade. The verification work consists of two parts, including 22 tasks. Part 1 contains 19 short answer tasks, part 2 contains

1. What is the charge of the nucleus of an oxygen atom? 1) 2 2) +6 3) +7 4) +8 2. What is common in atoms 1 1H, 2 1H, 3 1H? 1) Mass number 2) Number of protons 3) Number of neutrons 4) Radioactive properties Entry tests

Lesson 10 Redox reactions. Electrolysis Test 1 1. The oxidation process is reflected by the scheme 1) CO 2 3 CO 2 3) CO 2 CO 2) A1 3 C 4 CH 4 4) CH 4 CO 2 2. In the reaction of chromium oxide (sh) with aluminum

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Option 1 1. Make molecular and ion-molecular equations of reactions occurring before the formation of medium salts between substances: a) zinc nitrate + potassium hydroxide; b) calcium hydroxide + sulfuric

Code Part 1 Part 2 C1 C2 C3 C4 C5 C6 Ʃ Final score Final score (out of 100 points) (out of 10 points) Introductory work for applicants to the 10th FH and HB classes Decision (correct answers are in bold)_