Municipal budgetary educational institution

“Secondary school No. 4, Shebekino, Belgorod region”

Features of solving and evaluating tasks 30-35 of the Unified State Exam in chemistry

Prepared by: Arnautova Natalya Zakharovna,

teacher of chemistry and biology

MBOU "Secondary school No. 4, Shebekino, Belgorod region"

2017

Methodology for assessing tasks with a detailed answer (main approaches to determining criteria and rating scales for completing tasks)

The basis of the methodology for assessing tasks with a detailed answer is a number of general provisions. The most important among them are the following:

Testing and evaluation of tasks with a detailed answer is carried out only through an independent examination based on the method of element-by-element analysis of the examinees' answers.

The use of the element-by-element analysis method makes it necessary to ensure that the wording of the task conditions clearly corresponds to the content elements being checked. The list of content elements tested by any assignment is consistent with the standard requirements for the level of preparation of high school graduates.

The criterion for assessing the completion of a task using the method of element-by-element analysis is to establish the presence in the answers of the examinees of the answer elements given
in the response model. However, another answer model proposed by the examinee may be accepted if it does not distort the essence of the chemical component of the task conditions.

The rating scale for task performance is established depending on the number of content elements included in the response model, and taking into account such factors as:

Level of complexity of the content being tested;

A specific sequence of actions that should be carried out when completing a task;

Unambiguous interpretation of the task conditions and possible options for wording the answer;

Compliance of the assignment conditions with the proposed assessment criteria for individual content elements;

Approximately the same level of difficulty for each of the content elements tested by the task.

When developing assessment criteria, the features of the content elements of all five long-answer tasks included in the examination paper are taken into account. It is also taken into account that the records of the examinees’ answers can be either very general, streamlined and not specific, or too brief
and insufficiently reasoned. Close attention is paid to highlighting the elements of the answer that are worth one point. This takes into account the inevitability of a gradual increase in the difficulty of obtaining each subsequent point
for a correctly formulated element of content.

When drawing up a scale for grading calculation problems (33 and 34), the possibility of different ways of solving them is taken into account, and therefore, the presence in the examinee’s answer of the main stages and results of completing the tasks indicated
in the evaluation criteria. Let us illustrate the methodology for assessing tasks with a detailed answer using specific examples.

2017-2018 academic year

Tasks

Maximum score

Job level

Task 30

2016-2017

Tasks 30 are aimed at testing the ability to determine the degree of oxidation of chemical elements, determine the oxidizing agent and the reducing agent, predict the products of redox reactions, establish the formulas of substances missed in the reaction scheme, draw up an electronic balance, and on its basis assign coefficients in reaction equations.

The scale for assessing the performance of such tasks includes the following elements:

 an electronic balance has been compiled – 1 point;

 the oxidizing agent and the reducing agent are indicated – 1 point.

 formulas of missing substances are determined and coefficients are assigned
in the equation of redox reaction – 1 point.

Example task:

Using the electron balance method, create an equation for the reaction

Na 2 SO 3 + … + KOH K 2 MnO 4 + … + H 2 O

Identify the oxidizing agent and the reducing agent.

Points

Possible answer

Mn +7 + ē → Mn +6

S +4 – 2ē → S +6

Sulfur in the +4 oxidation state (or sodium sulfite due to sulfur in the +4 oxidation state) is a reducing agent.

Manganese in oxidation state +7 (or potassium permanganate due to manganese
in the oxidation state +7) – oxidizing agent.

Na 2 SO 3 + 2KMnO 4 + 2KOH = Na 2 SO 4 + 2K 2 MnO 4 + H 2 O

The answer is correct and complete:

the degree of oxidation of elements that are, respectively, an oxidizing agent and a reducing agent in the reaction is determined;

oxidation and reduction processes were recorded, and an electronic (electron-ion) balance was compiled on their basis;

the missing substances in the reaction equation are determined, all the coefficients are placed

Maximum score

When assessing the examinee’s answer, it is necessary to take into account that there are no uniform requirements for the formatting of the answer to this task. As a result, the compilation of both electronic and electron-ion balances is accepted as the correct answer, and the indication of the oxidizing agent and reducing agent can be done in any clearly understandable way. However, if the answer contains elements of the answer that are mutually exclusive in meaning, then they cannot be considered correct.

2018 format tasks

1. Task 30 (2 points)

To complete the task, use the following list of substances: potassium permanganate, hydrogen chloride, sodium chloride, sodium carbonate, potassium chloride. It is permissible to use aqueous solutions of substances.

From the proposed list of substances, select substances between which an oxidation-reduction reaction is possible, and write down the equation for this reaction. Make an electronic balance, indicate the oxidizing agent and reducing agent.

Explanation.

Let's write the reaction equation:

Let's create an electronic balance:

Chlorine in oxidation state −1 is a reducing agent. Manganese in the oxidation state +7 is an oxidizing agent.TOTAL 2 points

substances are selected, the equation of the redox reaction is written, and all the coefficients are set.

oxidation and reduction processes were recorded, and an electronic (electron-ion) balance was compiled on their basis; which are respectively the oxidizing agent and the reducing agent in the reaction;

There was an error in only one of the response elements listed above

There were errors in two of the above response elements

All elements of the answer are written incorrectly

Maximum score

2018 format tasks

1. Task 31 (2 points)

To complete the task, use the following list of substances: potassium permanganate, potassium bicarbonate, sodium sulfite, barium sulfate, potassium hydroxide. It is permissible to use aqueous solutions of substances.

Explanation.

Possible answer:

2. Task 31

To complete the task, use the following list of substances: hydrogen chloride, silver(I) nitrate, potassium permanganate, water, nitric acid. It is permissible to use aqueous solutions of substances.

From the proposed list of substances, select substances between which an ion exchange reaction is possible. Write down the molecular, complete and abbreviated ionic equations for this reaction.

Explanation.

Possible answer:

Task 32. 2018 format tasks

In the condition of task 32, testing knowledge of the genetic relationship of various classes of inorganic substances, a description of a specific chemical experiment is proposed, the progress of which the examinees will have to illustrate using the equations of the corresponding chemical reactions. The grading scale for the task remains, as in 2016, equal to 4 points: each correctly written reaction equation is scored 1 point.

Example task:

Iron was dissolved in hot concentrated sulfuric acid. The resulting salt was treated with an excess of sodium hydroxide solution. The brown precipitate that formed was filtered and calcined. The resulting substance was heated with iron.

Write equations for the four reactions described.

Contents of the correct answer and assessment instructions(other wording of the answer is allowed that does not distort its meaning)

Points

Possible answer

Four equations for the described reactions are written:

1) 2Fe + 6H 2 SO 4
Fe 2 (SO 4 ) 3 + 3SO 2 + 6H 2 O

2) Fe 2 (SO 4 ) 3 + 6NaOH = 2Fe(OH) 3 + 3Na 2 SO 4

3) 2Fe(OH) 3
Fe 2 O 3 + 3H 2 O

4) Fe 2 O 3 + Fe = 3FeO

All reaction equations are written incorrectly

Maximum score

It should be noted that the absence of coefficients (at least one) before the formulas of substances in reaction equations is considered an error. No points are awarded for such an equation.

Task 33. 2018 format tasks

Tasks 33 test the assimilation of knowledge about the relationship of organic substances and include checking five elements of content: the correctness of writing five reaction equations corresponding to the diagram - a “chain” of transformations. When writing reaction equations, examinees must use the structural formulas of organic substances. The presence of each checked content element in the answer is scored 1 point. The maximum number of points for completing such tasks is 5.

Example task:

Write the reaction equations that can be used to carry out the following transformations:

When writing reaction equations, use the structural formulas of organic substances.

Contents of the correct answer and assessment instructions
Other wording of the answer is allowed that does not distort its meaning)

Points

Possible answer

Five reaction equations have been written corresponding to the transformation scheme:

Five reaction equations written correctly

Four reaction equations written correctly

Three reaction equations written correctly

Two reaction equations written correctly

One reaction equation written correctly

All elements of the answer are written incorrectly

Maximum score

Let us note that in the examinee’s answer it is permissible to use structural formulas of different types (expanded, contracted, skeletal), which unambiguously reflect the bond order of atoms and the relative arrangement of substituents and functional groups
in a molecule of organic matter.

Task 34. 2018 format tasks

Tasks 34 are calculation problems. Their implementation requires knowledge of the chemical properties of substances and involves the implementation of a certain set of actions to ensure that the correct answer is obtained. Among such actions we name the following:

– drawing up equations of chemical reactions (according to the data of the problem conditions) necessary to perform stoichiometric calculations;

– performing calculations necessary to find answers to questions
in the problem statement there are questions;

– formulating a logically substantiated answer to all questions posed in the task conditions (for example, establishing a molecular formula).

However, it should be borne in mind that not all of the named actions must necessarily be present when solving any calculation problem, and in some cases some of them can be used more than once.

The maximum score for completing the task is 4 points. When checking, you should first of all pay attention to the logical validity of the actions performed, since some tasks can be solved in several ways. At the same time, in order to objectively evaluate the proposed method for solving the problem, it is necessary to check the correctness of the intermediate results that were used to obtain the answer.

Example task:

Determine the mass fractions (in%) of iron(II) sulfate and aluminum sulfide
in a mixture if, when 25 g of this mixture is treated with water, a gas is released, which completely reacts with 960 g of a 5% solution of copper sulfate.

In your answer, write down the reaction equations that are indicated in the problem statement,
and provide all the necessary calculations (indicate the units of measurement of the required physical quantities).

Points

Possible answer

The reaction equations were compiled:

The amount of hydrogen sulfide is calculated:

The amount of substance and mass of aluminum sulfide and iron(II) sulfate are calculated:

The mass fractions of iron(II) sulfate and aluminum sulfide in the initial mixture were determined:

ω(FeSO 4 ) = 10 / 25 = 0.4, or 40%

ω(Al 2 S 3 ) = 15 / 25 = 0.6, or 6 0%

The answer is correct and complete:

the answer correctly contains the reaction equations corresponding to the conditions of the task;

calculations have been carried out correctly using the necessary physical quantities specified in the task conditions;

a logically substantiated relationship between the physical quantities on the basis of which calculations are carried out is demonstrated;

in accordance with the task conditions, the required physical quantity is determined

There was an error in only one of the response elements listed above

All elements of the answer are written incorrectly

Maximum score

When checking the answer, the examinee must take into account the fact that if the answer contains an error in calculations in one of the three elements (second, third or fourth), which led to an incorrect answer, the mark for completing the task is reduced by only 1 point.

Task 35. 2018 format tasks

Tasks 35 involve determining the molecular formula of a substance. Completing this task includes the following sequential operations: carrying out the calculations necessary to establish the molecular formula of an organic substance, writing the molecular formula of an organic substance, drawing up a structural formula of a substance that uniquely reflects the order of bonds of atoms in its molecule, writing a reaction equation that meets the conditions of the task.

The grading scale for task 35 in part 2 of the examination paper will be 3 points.

Tasks 35 use a combination of tested content elements - calculations, on the basis of which they come to determine the molecular formula of a substance, compile a general formula of a substance, and then determine the molecular and structural formula of a substance on its basis.

All these actions can be performed in different sequences. In other words, the examinee can come to the answer in any logical way available to him. Therefore, when assessing a task, the main attention is paid to the correctness of the chosen method for determining the molecular formula of a substance.

Example task:

When a sample of some organic compound weighing 14.8 g is burned, 35.2 g of carbon dioxide and 18.0 g of water are obtained.

It is known that the relative vapor density of this substance with respect to hydrogen is 37. During the study of the chemical properties of this substance, it was established that when this substance interacts with copper(II) oxide, a ketone is formed.

Based on the data of the task conditions:

1) make the calculations necessary to establish the molecular formula of an organic substance (indicate the units of measurement of the required physical quantities);

write down the molecular formula of the original organic substance;

2) draw up a structural formula of this substance, which unambiguously reflects the order of bonds of atoms in its molecule;

3) write the equation for the reaction of this substance with copper(II) oxide using the structural formula of the substance.

Contents of the correct answer and assessment instructions

(other wording of the answer is allowed that does not distort its meaning)

Points

Possible answer

The amount of combustion product substance found:

The general formula of the substance is C x H y O z

n(CO2) = 35.2 / 44 = 0.8 mol; n (C) = 0.8 mol

n(H 2 O) = 18.0 / 18 = 1.0 mol; n(H) = 1.0 ∙ 2 = 2.0 mol

m(O) = 14.8 – 0.8 ∙ 12 – 2 = 3.2 g; n(O) = 3.2 ⁄ 16 = 0.2 mol

The molecular formula of the substance was determined:

x:y:z = 0.8:2:0.2 = 4:10:1

The simplest formula is C 4 H 10 O

M simple (C 4 H 10 O) = 74 g/mol

M source (C x H y O z ) = 37 ∙ 2 = 74 g/mol

Molecular formula of the starting substance – C 4 H 10 O

The structural formula of the substance has been compiled:

The equation for the reaction of a substance with copper(II) oxide is written:

The answer is correct and complete:

the calculations necessary to establish the molecular formula of a substance have been correctly performed; the molecular formula of the substance is written down;

the structural formula of an organic substance is written down, which reflects the bond order and relative arrangement of substituents and functional groups in the molecule in accordance with the assignment conditions;

the equation of the reaction, which is indicated in the task conditions, is written using the structural formula of an organic substance

There was an error in only one of the response elements listed above

There were errors in two of the above response elements

There were errors in three of the above response elements

All elements of the answer are written incorrectly

All elements of the answer are written incorrectly

Maximum score

TOTAL part 2

2+2+ 4+5+4 +3=20 points

Bibliography

1. Methodological materials for chairmen and members of subject commissions of the constituent entities of the Russian Federation on checking the completion of tasks with a detailed answer of the 2017 Unified State Examination papers. Article “Methodological recommendations for assessing the performance of Unified State Examination tasks with a detailed question.” Moscow, 2017.

2. FIPI project of control and measuring materials for the Unified State Exam 2018.

3. Demo versions, specifications, codifiers of the Unified State Exam 2018. FIPI website.

4. Information about planned changes to the 2018 CMM. FIPI website.

5.Site “I will solve the Unified State Exam”: chemistry, for an expert.

How many points are given for each Unified State Examination task in chemistry? Evaluation criteria for the Unified State Exam in Chemistry 2019: points and grades, conversion table, as well as the structure of the exam, testing methodology and main changes in the new year. In 2019, tasks for the Unified State Exam in chemistry began to contain a larger number of mathematical elements, calculations of physical quantities, and the testing of the basic theoretical course of chemistry became deeper. At the same time, the number of tasks has decreased, now instead of 40 questions, the student will have to solve 35 (according to other sources, 34). Accordingly, the rating scale has changed; for the Unified State Examination in Chemistry 2019, the primary score has become lower – by 4 units.

All tasks are scored differently, and you can earn up to 5 points for difficult tasks. Therefore, to enter specialized universities, it is necessary to study the subject as deeply as possible.

Table of criteria for assessing USE 2019 tasks in chemistry, taking into account the new requirements:

Job number	Maximum score
35	3

Assessment of tasks is carried out according to an established methodology, while for complex tasks where logic is required, points are assigned using special analytical tables. If the answer best meets the requirements of the analysis, you can get up to 5 points for it. If the student has only partially developed the topic, the number of points is reduced. For an uncompleted task, 0 points are awarded.

Complex assignments are checked by two experts. If there is a strong discrepancy in scores, then a third specialist is involved. This ensures the most effective and objective assessment of graduates’ knowledge.

Conversion table for the Unified State Exam 2019 in chemistry from points to grades:

Number of points	Grade

The structure of the Unified State Examination tasks in chemistry in 2019 includes 29 questions with a short answer, as well as 5 with an extended answer.

The duration of the exam is 210 minutes; according to the standard, simple questions should take about 3 minutes, complex ones - up to 15. As for the minimum score for admission to specialized universities, each higher educational institution sets its own requirements. For example, to enter the Faculty of Chemistry of Moscow State University or the prestigious Moscow Medical University, you must score at least 50 points.

But usually the overall passing score for prestigious universities is 400-470 (at least less for the chemistry department, more for the medical department), and admission to Moscow State University does not depend on chemistry alone, so if you don’t have enough points, you can get in mathematics, biology, Russian and internal entrance exams.

Significant changes in the Unified State Exam are also observed in other subjects.

To successfully pass chemistry, it is recommended to spend most of your time solving problems and equations. During the test, you can use a calculator, periodic table and salt solubility. The electrochemical voltage series of metals is also allowed.

The evaluation criteria for the Unified State Exam in Chemistry 2019 are described quite clearly in the regulations, but each graduate has the right to appeal.

Table of conversion of points to OGE-2019 grades in chemistry

Graduates of 9th grade have their own assessment criteria. According to all KIM and GIA, the maximum you can score is 34 points. But if a graduate wants to go to a medical college, a specialized class, or some other specialized secondary education related to chemistry, pharmacy and medicine, he needs to score 23 points or higher.

Chemistry score conversion table for OGE-2019

Despite its apparent simplicity, scoring 9 points for the minimum passing grade is not so easy. You need to be able to solve problems, navigate formulas, and have at least a minimal knowledge of theory. Those who pass with a bad mark will remain for the second year if they fail the retake.

Scoring table for assignments:

Job number
	2 (1 – if partially resolved)
	2 (1 – if partially resolved)
	2 (1 – if 2/3 correct)
	2 (1 – if 2/3 correct)

Many schoolchildren, to be on the safe side, start solving difficult tasks right away. If you solve them all without errors, you can score 19 points at once, that is, a “four”. However, this implies a complete solution to the task, otherwise it will be scored 1 point, or even not at all.

The assessment criteria for chemistry tests change every year, the rules become stricter, since there is an idea among the government that education is not of sufficient quality. This, of course, has no basis, because schoolchildren study worse not because of the program, but mostly because of overload.

What will go into the certificate? What to do if the Unified State Examination in chemistry is written as a bad mark?

If the Unified State Exam in chemistry is not passed, but the grades in mathematics and Russian are normal, the student will simply be given a certificate. And they will also give you a Unified State Exam certificate, where chemistry simply won’t be included. However, the exam can be retaken after a year. There is only one minus here - the overall score may not be enough for admission, and if the university requires chemistry without fail, then they will not accept documents at all. Accordingly, the student loses time, and young men may even be drafted into the army, after which it will be even more difficult to retake the test.

If the grade for the year is 4 or 5, and the Unified State Exam in Chemistry is passed with a 3 or 4 (that is, a decrease in the score), what will go into the certificate? The one year mark will be reached. If the Unified State Examination is passed with a 5, and in a year 3, then it also does not affect the certificate. But every specific school where they are required to calculate the arithmetic average.

Why is this happening? Because no one checks this calculation later. Based on this, it is better to resolve the issue in advance with the chemistry teacher and class teacher; usually in normal schools, teachers try to meet the graduates halfway. If a child has a 4, but he pushed himself and passed the Unified State Exam with a 5, why not help him?

But! We must remember that no one needs grades on the admission certificate, especially in chemistry. Today in 99% of cases they look only at the Unified State Examination certificate.

The work consists of two parts:
- part 1 - tasks with a short answer (26 - basic level, 9 advanced),
- part 2 - tasks with detailed answers (5 high-level tasks).
The maximum number of primary points remains the same: 64.
However, some changes will be made:

1. In tasks of basic difficulty level(formerly Part A) will include:
a) 3 tasks (6,11,18) with multiple choice (3 out of 6, 2 out of 5)
b) 3 tasks with an open answer (calculation problems), the correct answer here will be the result of the calculations, recorded with a specified degree of accuracy;
Like other basic level assignments, these assignments will be worth 1 initial point.

2. Advanced level tasks (formerly Part B) will be of one type: compliance assignments. They will be scored 2 points (if there is one error - 1 point);

3. The question on the topic: “Reversible and irreversible chemical reactions. Chemical equilibrium. Shift of equilibrium under the influence of various factors” has been moved from basic level tasks to advanced ones.
However, the issue of nitrogen-containing compounds will be checked at a basic level.

4. The time for the unified exam in chemistry will be increased from 3 hours to 3.5 hours(from 180 to 210 minutes).

In 2018, during the main period, more than 84.5 thousand people took part in the Unified State Examination in Chemistry, which is more than 11 thousand people more than in 2017. The average score for the examination work remained virtually unchanged and amounted to 55.1 points (in 2017 - 55.2). The share of graduates who did not pass the minimum score was 15.9%, which is slightly higher than in 2017 (15.2%). For the second year, there has been an increase in the number of high-scoring students (81-100 points): in 2018, the increase was 1.9% compared to 2017 (in 2017 - 2.6% compared to 2016). A certain increase in 100-point scores was also noted: in 2018 it amounted to 0.25%. The results obtained may be due to more targeted preparation of high school students for certain models of tasks, primarily those of a high level of complexity, included in part 2 of the exam version. Another reason is the participation of winners of Olympiads in the Unified State Exam in Chemistry, which gives the right to non-competitive admission provided they complete the examination work with more than 70 points. A certain role in increasing the results could also have been played by the placement in the open task bank of a larger number of sample tasks included in the exam options. Thus, one of the main tasks for 2018 was to strengthen the differentiating ability of individual tasks and the exam version as a whole.

More detailed analytical and methodological materials for the 2018 Unified State Exam are available here.

Our website contains about 3,000 tasks to prepare for the Unified State Exam in Chemistry in 2018. The general outline of the examination work is presented below.

EXAMINATION PLAN FOR THE USE OF CHEMISTRY 2019

Designation of the level of difficulty of the task: B - basic, P - advanced, V - high.

Content elements and activities tested	Task difficulty level	Maximum score for completing the task	Estimated task completion time (min.)
Exercise 1. The structure of the electronic shells of atoms of elements of the first four periods: s-, p- and d-elements. Electronic configuration of an atom. Ground and excited states of atoms.
Task 2. Patterns of changes in the chemical properties of elements and their compounds by periods and groups. General characteristics of metals of groups IA–IIIA in connection with their position in the Periodic Table of Chemical Elements D.I. Mendeleev and the structural features of their atoms. Characteristics of transition elements - copper, zinc, chromium, iron - according to their position in the Periodic Table of Chemical Elements D.I. Mendeleev and the structural features of their atoms. General characteristics of non-metals of groups IVA–VIIA in connection with their position in the Periodic Table of Chemical Elements D.I. Mendeleev and the structural features of their atoms
Task 3. Electronegativity. Oxidation state and valence of chemical elements
Task 4. Covalent chemical bond, its varieties and mechanisms of formation. Characteristics of covalent bonds (polarity and bond energy). Ionic bond. Metal connection. Hydrogen bond. Substances of molecular and non-molecular structure. Type of crystal lattice. Dependence of the properties of substances on their composition and structure
Task 5. Classification of inorganic substances. Nomenclature of inorganic substances (trivial and international)
Task 6. Characteristic chemical properties of simple metal substances: alkali, alkaline earth, aluminum; transition metals: copper, zinc, chromium, iron. Characteristic chemical properties of simple nonmetallic substances: hydrogen, halogens, oxygen, sulfur, nitrogen, phosphorus, carbon, silicon. Characteristic chemical properties of oxides: basic, amphoteric, acidic
Task 7. Characteristic chemical properties of bases and amphoteric hydroxides. Characteristic chemical properties of acids. Characteristic chemical properties of salts: medium, acidic, basic; complex (using the example of hydroxo compounds of aluminum and zinc). Electrolytic dissociation of electrolytes in aqueous solutions. Strong and weak electrolytes. Ion exchange reactions
Task 8. Characteristic chemical properties of inorganic substances: - simple substances-metals: alkali, alkaline earth, magnesium, aluminum, transition metals (copper, zinc, chromium, iron); - acids;
Task 9. Characteristic chemical properties of inorganic substances: – simple metal substances: alkali, alkaline earth, magnesium, aluminum, transition metals (copper, zinc, chromium, iron); - simple non-metal substances: hydrogen, halogens, oxygen, sulfur, nitrogen, phosphorus, carbon, silicon; - oxides: basic, amphoteric, acidic; - bases and amphoteric hydroxides; - acids; - salts: medium, acidic, basic; complex (using the example of hydroxo compounds of aluminum and zinc)
Task 10. Interrelation of inorganic substances
Task 11. Classification of organic substances. Nomenclature of organic substances (trivial and international)
Task 12. Theory of the structure of organic compounds: homology and isomerism (structural and spatial). Mutual influence of atoms in molecules. Types of bonds in molecules of organic substances. Hybridization of carbon atomic orbitals. Radical. Functional group
Task 13. Characteristic chemical properties of hydrocarbons: alkanes, cycloalkanes, alkenes, dienes, alkynes, aromatic hydrocarbons (benzene and homologues of benzene, styrene). Main methods of producing hydrocarbons (in the laboratory)
Task 14. Characteristic chemical properties of saturated monohydric and polyhydric alcohols, phenol. Characteristic chemical properties of aldehydes, saturated carboxylic acids, esters. The main methods for obtaining oxygen-containing organic compounds (in the laboratory).
Task 15. Characteristic chemical properties of nitrogen-containing organic compounds: amines and amino acids. The most important methods for obtaining amines and amino acids. Biologically important substances: fats, carbohydrates (monosaccharides, disaccharides, polysaccharides), proteins
Task 16. Characteristic chemical properties of hydrocarbons: alkanes, cycloalkanes, alkenes, dienes, alkynes, aromatic hydrocarbons (benzene and homologues of benzene, styrene). The most important methods for producing hydrocarbons. Ionic (V.V. Markovnikov’s rule) and radical reaction mechanisms in organic chemistry
Task 17. Characteristic chemical properties of saturated monohydric and polyhydric alcohols, phenol, aldehydes, carboxylic acids, esters. The most important methods for obtaining oxygen-containing organic compounds
Task 18. The relationship between hydrocarbons, oxygen-containing and nitrogen-containing organic compounds
Task 19. Classification of chemical reactions in inorganic and organic chemistry
Task 20. Reaction speed, its dependence on various factors
Task 21. Redox reactions.
Task 22. Electrolysis of melts and solutions (salts, alkalis, acids)
Task 23. Hydrolysis of salts. Aqueous solution environment: acidic, neutral, alkaline
Task 24. Reversible and irreversible chemical reactions. Chemical balance. Shift of equilibrium under the influence of various factors
Task 25. Qualitative reactions to inorganic substances and ions. Qualitative reactions of organic compounds
Task 26. Rules for working in the laboratory. Laboratory glassware and equipment. Safety rules when working with caustic, flammable and toxic substances, household chemicals. Scientific methods for studying chemical substances and transformations. Methods for separating mixtures and purifying substances. The concept of metallurgy: general methods of producing metals. General scientific principles of chemical production (using the example of industrial production of ammonia, sulfuric acid, methanol). Chemical pollution of the environment and its consequences. Natural sources of hydrocarbons, their processing. High molecular weight compounds. Polymerization and polycondensation reactions. Polymers. Plastics, fibers, rubbers
Task 27. Calculations using the concept of “mass fraction of a substance in solution”
Task 28. Calculations of volumetric ratios of gases during chemical reactions. Calculations using thermochemical equations
Task 29. Calculation of the mass of a substance or volume of gases based on a known amount of a substance, mass or volume of one of the substances participating in the reaction
Task 30 (C1). Redox reactions
Task 31 (C2). Electrolytic dissociation of electrolytes in aqueous solutions. Strong and weak electrolytes. Ion exchange reactions.
Task 32 (C3). Reactions confirming the relationship between various classes of inorganic substances
Task 33 (C4). Reactions confirming the relationship of organic compounds
Task 34 (C5). Calculations using the concepts of “solubility”, “mass fraction of a substance in solution”. Calculations of the mass (volume, amount of substance) of reaction products, if one of the substances is given in excess (has impurities), if one of the substances is given in the form of a solution with a certain mass fraction of the dissolved substance. Calculations of the mass or volume fraction of the yield of the reaction product from the theoretically possible. Calculation of the mass fraction (mass) of a chemical compound in a mixture
Task 35 (C6). Establishing the molecular and structural formula of a substance

APPROXIMATE 2019 SCALE

Correspondence between minimum primary scores and 2019 minimum test scores. Order on amendments to Appendix No. 1 to the order of the Federal Service for Supervision in Education and Science.

What to pay attention to when preparing for the Unified State Exam 2017

In 2016, 75,096 graduates took the chemistry exam, which is approximately the same as in the previous two years.

Did not cross the established minimum threshold for the number of points scored (less than 34) - 13.2%, passed satisfactorily (up to 60) - 47.3%, good (up to 80) - 33.7%, excellent (up to 100) - 5, 8%.

There were 40 tasks in total: 35 with a short answer made up the first part, five with a detailed answer - the second.

In the examination paper in chemistry in 2016 (compared to 2015), changes were made to six tasks. Instead of choosing one answer, you had to choose 2-3 or give the answer as a number with a given degree of accuracy. In two tasks of increased complexity (34 and 35), instead of multiple choice, it was necessary to establish correspondences between elements of two sets. Unfortunately, these changes resulted in poor results in completing the listed tasks.

The tasks of increased complexity turned out to be too difficult for the examinees, and the percentage of those who coped with them was small. This was, for example, task 39. It turned out that only a few well-prepared graduates can carry out calculations using reaction equations. Even among the guys who had good training, only 19.6% were able to cope with this task. Apparently, those who are now preparing for the Unified State Exam 2017 need to pay special attention to such tasks and work out the algorithm for completing them.

At the same time, another task of increased complexity (number 36) on redox reactions based on electronic balance was completed by 61.5% of the examinees.

In 2017, some changes are planned for the chemistry exam. This is caused by the desire to more objectively check the success of mastering the subject.

Fewer tasks are expected: instead of 40, as in 2016, only 34. The primary score from 64 in 2016 will decrease to 58-60.

Graduates need to be prepared to demonstrate not only successful mastery of the general education program in the subject, but also the ability to apply acquired knowledge, skills, and abilities in educational situations. For example, classify organic and inorganic substances, describe their chemical properties. In the task, it may be necessary to indicate the numbers of acids from the listed substances, that is, it is necessary to show knowledge of the characteristics of this class of substances - the presence of only hydrogen ions as cations. Or, for example, the following task: with which of the listed substances will phosphorus and magnesium react (the main thing here is to remember that these two substances can be reducing agents, and therefore can react with an oxidizing substance).

There will also be tasks to establish correspondence between the two groups of proposed substances. For example, determine which substances from one group can react with substances from another.

From these examples it is clear that nothing overly difficult, beyond the school curriculum, will be required from the graduate, but the knowledge must be systematic, and not fragmentary - this is the main factor for successfully passing any exam, not only in chemistry.

Familiarize yourself with the codifier of tested content elements and specifications posted on the FIPI website, and let your child try the demo version of the Unified State Exam. After this, together honestly assess your chances of passing this very difficult exam. You won't be able to beat it in one sitting even to the minimum point. If you completed the demo version with a low score, it may be worth looking for other options for continuing your studies, and therefore choosing other disciplines, the scores for which are passing to the newly chosen university, taking into account your real abilities and acquired knowledge base.

Yes, high scores on the Unified State Exam in chemistry will open the doors of many prestigious educational institutions. However, in this case, before cutting off, that is, deciding to take chemistry, you need to measure not just seven times, but seventy-seven. After all, the child’s future depends on success in the exam. As they say, whatever you studied for, that’s what you were good for. In the eleventh grade it is too late to start studying this complex subject from scratch. To repeat - yes, but to teach as a completely new, completely unfamiliar discipline - no. Be realistic.

But if the child still chooses to take the Unified State Exam in Chemistry, it is necessary to make every effort to thoroughly master the educational program for this course, which will be rewarded by receiving the maximum number of points, admission to the chosen university and successful studies there.