How many points are given for each task of the exam in chemistry. Criteria for evaluating the exam in chemistry 2019: points and grades, a translation table, as well as the structure of the exam, the test methodology and the main changes in the new year. In 2019, tasks for the exam in chemistry began to contain more mathematical elements, calculations of physical quantities, and the verification of the main 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 assessment scale has changed, for the 2019 USE in chemistry the primary score has become lower - by 4 units.

All tasks are evaluated in different ways, for difficult tasks you can earn up to 5 points. Therefore, for admission to specialized universities, it is necessary to study the subject as deeply as possible.

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

Job number	Maximum score
35	3

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

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

Conversion table for the 2019 exam in chemistry from points to grades:

Number of points	Grade

The structure of USE assignments in chemistry in 2019 includes 29 questions with a short answer, as well as 5 with a detailed one.

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

But usually the total passing score in prestigious universities is 400-470 (at least less for the chemistry department, more for the medical department), and admission to the same Moscow State University does not depend on chemistry alone, so if there are not enough points, you can get it in mathematics, biology, Russian and internal entrance examinations.

Significant changes in the USE are also observed in other subjects.

To successfully pass chemistry, it is recommended that you devote most of your time to solving problems and the equation. During delivery, you can use a calculator, periodic table and salt solubility. The electrochemical series of metal voltages is also permitted.

The criteria for evaluating the exam in chemistry 2019 are described quite clearly in the regulations, but each graduate has the right to appeal.

Table of transfers of points to assessments of the OGE-2019 in chemistry

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

Table of transfers of points in chemistry for the OGE-2019

Despite the seeming simplicity, it is not so easy to get 9 points for the minimum passing grade. You need to be able to solve problems, navigate formulas, at least have a minimal knowledge of theory. Those who pass for a deuce will stay for the second year if they fail the retake too.

Score table for assignments:

Job number
	2 (1 - if partially solved)
	2 (1 - if partially solved)
	2 (1 - if true by 2/3)
	2 (1 - if true by 2/3)

Many schoolchildren, in order to play it safe, begin to solve immediately with difficult tasks. If you solve them all without mistakes, you can get 19 points at once, that is, for the "four". However, this implies a complete solution to the task, otherwise it will be estimated at 1 point, or even not at all.

The criteria for assessing testing in chemistry change every year, the rules become stricter, as there is an idea among the government about insufficient quality education. This, of course, is unfounded, because schoolchildren do worse not because of the program, but mostly because of overload.

What will go to the certificate? What if the exam in chemistry is written with a two?

If the exam in chemistry is not passed, and in mathematics and Russian there are normal grades, the student will simply be given a certificate. And they will also give a USE certificate, where chemistry simply will not be entered. In this case, the exam can be retaken in a year. There is only one minus here - the total score for admission may not be enough, and if the university requires chemistry without fail, then documents will not be accepted at all. Accordingly, the student is wasting time, and young men may even be taken into the army, after which it will be even more difficult to retake.

If a grade is 4 or 5 for a year, and the USE in chemistry is passed at 3 or 4 (that is, a decrease in the score), what will go to the certificate? The annual mark will go. If the exam is passed for 5, and for a year 3, then it also does not affect the certificate. But each specific school, where they were obliged to count the arithmetic mean.

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

But! It must be remembered that no one needs marks in the certificate upon admission, and especially in chemistry. They look today in 99% of cases only at the USE certificate.

In 2018, in the main period, more than 84.5 thousand people took part in the USE in chemistry, which is more than 11 thousand people more than in 2017.The average score on the examination work did not practically change and amounted to 55.1 points (in 2017 - 55.2). The share of graduates who did not overcome 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-scorers (81-100 points): in 2018, the increase was 1.9% compared to 2017 (in 2017 - 2.6% compared to 2016). There was also a certain increase in 100 points: in 2018 it amounted to 0.25%. The results obtained may be due to a more targeted preparation of high school students for certain models of tasks, first of all, of a high level of complexity, included in part 2 of the examination option. Another reason is the participation in the USE in chemistry of the winners of the Olympiads, who give the right to out-of-competition admission, provided that the examination work is more than 70 points. The placement in the open bank of assignments of a larger number of samples of assignments included in the examination options could also play a certain role in improving the results. Thus, one of the main tasks for 2018 was to strengthen the differentiating ability of individual tasks and the examination option as a whole.

More detailed analytical and methodological materials of the USE 2018 are available here.

Our website contains about 3000 tasks for preparing for the exam in chemistry in 2018. The general outline of the examination work is presented below.

THE EXAMINATION PLAN OF THE USE IN CHEMISTRY 2019

Designation of the level of difficulty of the task: B - basic, P - increased, C - high.

Verifiable content items and activities	Difficulty level of the task	Maximum score for completing the task	Estimated time to complete the task (min.)
Exercise 1. The structure of the electron shells of atoms of the elements of the first four periods: s-, p- and d-elements. Electronic configuration of the atom. Ground and excited state of atoms.
Task 2. Regularities of changes in the chemical properties of elements and their compounds by periods and groups. General characteristics of metals of groups IA – IIIIA in connection with their position in the Periodic Table of Chemical Elements Mendeleev and the structural features of their atoms. Characterization of transition elements - copper, zinc, chromium, iron - by their position in the Periodic Table of Chemical Elements D.I. Mendeleev and the peculiarities of the structure of their atoms. General characteristics of non-metals of IVА – VIIА groups 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. Covalent bond characteristics (polarity and bond energy). Ionic bond. Metallic bond. Hydrogen bond. Substances of molecular and non-molecular structure. Crystal lattice type. 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. Typical chemical properties of simple substances-metals: alkali, alkaline earth, aluminum; transition metals: copper, zinc, chromium, iron. Typical chemical properties of simple non-metal substances: hydrogen, halogens, oxygen, sulfur, nitrogen, phosphorus, carbon, silicon. Typical chemical properties of oxides: basic, amphoteric, acidic
Task 7. Characteristic chemical properties of bases and amphoteric hydroxides. Characteristic chemical properties of acids. Typical chemical properties of salts: medium, acidic, basic; complex (for example, hydroxo compounds of aluminum and zinc). Electrolytic dissociation of electrolytes in aqueous solutions. Strong and weak electrolytes. Ion exchange reactions
Task 8. Typical chemical properties of inorganic substances: - simple substances-metals: alkali, alkaline earth, magnesium, aluminum, transition metals (copper, zinc, chromium, iron); - acids;
Task 9. Typical chemical properties of inorganic substances: - simple substances-metals: 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, sour, basic; complex (for example, hydroxo compounds of aluminum and zinc)
Task 10. The relationship of inorganic substances
Task 11. Classification of organic substances. Organic Nomenclature (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. Typical chemical properties of hydrocarbons: alkanes, cycloalkanes, alkenes, dienes, alkynes, aromatic hydrocarbons (benzene and homologues of benzene, styrene). The main methods of obtaining hydrocarbons (in the laboratory)
Task 14. Typical chemical properties of saturated monohydric and polyhydric alcohols, phenol. Typical chemical properties of aldehydes, saturated carboxylic acids, esters. The main methods of obtaining oxygen-containing organic compounds (in the laboratory).
Task 15. Typical chemical properties of nitrogen-containing organic compounds: amines and amino acids. The most important ways to obtain amines and amino acids. Biologically important substances: fats, carbohydrates (monosaccharides, disaccharides, polysaccharides), proteins
Task 16. Typical chemical properties of hydrocarbons: alkanes, cycloalkanes, alkenes, dienes, alkynes, aromatic hydrocarbons (benzene and homologues of benzene, styrene). The most important ways to obtain hydrocarbons. Ionic (V.V. Markovnikov's rule) and radical reaction mechanisms in organic chemistry
Task 17. Typical chemical properties of saturated monohydric and polyhydric alcohols, phenol, aldehydes, carboxylic acids, esters. The most important methods for the production of oxygen-containing organic compounds
Task 18. The relationship of 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. Salt hydrolysis. The environment of aqueous solutions: acidic, neutral, alkaline
Task 24. Reversible and irreversible chemical reactions. Chemical equilibrium. Equilibrium shift under the influence of various factors
Task 25. Qualitative reactions to inorganic substances and ions. Qualitative reactions of organic compounds
Task 26. Laboratory rules. Laboratory glassware and equipment. Safety rules when working with caustic, flammable and toxic substances, household chemicals. Scientific methods for the study of chemicals and transformations. Methods for separation of mixtures and purification of substances. The concept of metallurgy: general methods of obtaining metals. General scientific principles of chemical production (on 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 a solution"
Task 28. Calculations of volumetric ratios of gases in chemical reactions. Calculations by thermochemical equations
Task 29. Calculations of the mass of a substance or the volume of gases for 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 of various classes of inorganic substances
Task 33 (C4). Reactions confirming the relationship of organic compounds
Task 34 (C5). Calculations using the concepts "solubility", "mass fraction of a substance in a solution". Calculations of the mass (volume, amount of a substance) of the 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 solute. Calculations of the mass or volume fraction of the yield of the reaction product from the theoretically possible. Calculations of the mass fraction (mass) of a chemical compound in a mixture
Task 35 (C6). Determination of the molecular and structural formula of a substance

APPROXIMATE SCALE 2019

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

The basis for the changes in the 2016 examination model was the need to increase the objectivity of the assessment of the educational achievements of the examinees in accordance with the requirements of the Federal State Educational Standard for the preparation of high school graduates.

The main emphasis was placed on strengthening the activity basis and practice-oriented orientation of CMM. The formulation of these tasks led to the adjustment of approaches to the construction of individual tasks. As a result, some tasks were presented in the examination paper in a new format, due to which their focus on checking the formation, first of all, of those skills (educational actions) that are most indicative from the point of view of the completeness and success of mastering the subject was achieved. Among them, the skill deserves special attention. apply knowledge in the system, which involves the implementation of various actions in the process of mastering the subject: revealing classification signs of substances and reactions; explanation the essence of a particular process; establishment the relationship between the composition, structure and properties of substances; self-assessment the correctness of the chosen method of completing the task, etc.

Let us illustrate how the described approach was implemented in relation to the construction of specific tasks.

In part 1 of the 2016 examination paper, the format of six tasks of the basic level of difficulty has been changed. These are the following tasks:

· No. 6, the implementation of which provides for the application of generalized knowledge about the classification and nomenclature of inorganic substances. The result of this task is the establishment of three correct answers out of six proposed options;

· № 11 and № 18, their implementation provides for the use of generalized knowledge about the genetic relationship of inorganic and organic substances. The result of the tasks is the establishment of two correct answers out of five proposed options;

· No. 24, No. 25, No. 26 - these are calculation tasks. The answer to these problems, presented in a new form, is a number with a given degree of accuracy.

The main result of the change in the format of these tasks was that their implementation provides for a more varied sequence of educational actions than in the case of traditional tasks with a choice of answer. So, in particular, in order to select the correct answer, which is not specified in the form of ready-made options, but must be established independently, it requires the mandatory use of generalized knowledge of key concepts and patterns in interconnection. This is clearly illustrated by the following examples of changes in the format of assignments in 2015.

Task number 6

Among the listed substances:

Write down the numbers under which they are indicated.

Similarly, the format of tasks with serial number 18 has been changed, which are focused on checking the content element "genetic connection of organic substances".

Task number 24 (design problem)

The mass of potassium nitrate, which should be dissolved in 150 g of a solution with a mass fraction of this salt of 10% to obtain a solution with a mass fraction of 12%, is

1)

0.3 g

2)

2.0 g

3)

3.0 g

4)

3.4 g

Answer:

The number of one of the proposed answer options is recorded.

Calculate the mass of potassium nitrate (in grams), which should be dissolved in 150 g of a solution with a mass fraction of this salt of 10% to obtain a solution with a mass fraction of 12%.

Answer: ___________________ g (Write the number down to tenths.)

The tasks with serial numbers 25 and 26 are presented in a similar format.

Along with the change in the presentation format of some tasks in the examination paper in 2016, an adjustment was made regarding the distribution of tasks by difficulty levels and types of tested skills and methods of action. This adjustment resulted in the following changes.

In part 1 of the work, the format of two tasks of an increased level of complexity (their serial numbers 34 and 35) has been changed, which test the assimilation of knowledge of the characteristic chemical properties of hydrocarbons and oxygen-containing organic substances. In the work of 2015, these were “multiple choice” tasks and, as the practice of the USE showed, they did not fully meet the criteria for tasks of an increased level of complexity. In the work of 2016, these tasks are presented in the format of tasks that are more complex and more informative - “to establish a correspondence between the elements of two sets”. Thanks to this, the existing contradiction between the content of the task and the form of its presentation has been eliminated. The following are examples of these typical 2015 and 2016 assignments.

An example of adjusting the difficulty level of tasks with serial numbers 34 and 35.

Phenol reacts with

Answer:

Establish a correspondence between the starting substances and the products that are predominantly formed during their interaction with bromine.

Answer:	A	B	V	G

Another example of adjusting the level of difficulty of tasks was the change in the form of presentation of the task, focused on checking the assimilation of the content element “Chemical equilibrium; shift of chemical equilibrium ". This is one of the key concepts in the structure of the content line "Chemical reaction" and therefore the verification of its assimilation should be carried out taking into account the depth of study of this material in the course of chemistry. The tasks of the basic level of complexity, which in 2015 were focused on checking this element of content, did not adequately fulfill the above requirement. Therefore, based on the analysis of the results of such tasks, the expediency of checking this element of content was justified only with tasks of an increased level of complexity (their serial number in the work is 31).

Task number 31 (KIM USE 2016)

Establish a correspondence between the equation of a chemical reaction
and the direction in which the chemical equilibrium shifts with increasing pressure in the system.

EQUATION OF REACTION		DIRECTION OF DISPLACEMENT OF CHEMICAL EQUILIBRIUM
A) N 2 (g) + 3H 2 (g) 2NH 3 (g) B) 2H 2 (g) + O 2 (g) 2H 2 O (g) V) H 2 (g) + Cl 2 (g) 2НCl (g) G) SO 2 (g) + Cl 2 (g) SO 2 Cl 2 (g)		1) shifts towards reaction products 2) shifts towards the starting materials 3) practically does not shift
Answer:	A	B	V	G

Note that this approach to improving the CMM provides opportunities for a more objective and differentiated assessment of the educational achievements of the examinees at different levels. Namely:

· At the level of mastering the conceptual apparatus of the course of chemistry, general laws and methods of studying substances and reactions;

· At the level of application of knowledge of chemistry in the context of everyday life;

· At the level of development of intellectual skills, allowing to comprehend real situations, use their experience to gain new knowledge, find and explain the necessary solutions.

Demonstration version of control measuring materials
unified state examination

The demo is a sample of a CMM made according to the specification. Using his example, any future exam participant and the general public can familiarize themselves with what tasks and in what quantity are included in the examination work, what rules must be followed when completing tasks, what requirements are imposed on recording answers to tasks. The demo version provides an opportunity to get acquainted with the system for assessing the performance of tasks. Its structure contains instructions for checking and grading multiple choice questions, with short and detailed answers. Attached to it are the answers to all the tasks of the demo version.

When familiarizing yourself with the demo version of the CMM, it is important to keep in mind that it is not an exact copy of any version of the 2015 examination paper, but includes only typical tasks, moreover, only those that have already been used in the exam of previous years and have been successfully completed by graduates.

Materials of the FIPI website (http://www.fipi.ru)

The FIPI website contains the following regulatory, analytical, educational, methodological and informational materials that can be used in organizing the educational process and preparing students for the Unified State Exam.

- documents defining the structure and content of the KIM USE in chemistry in 2016;

- teaching materials for members and chairpersons of regional subject commissions to check the fulfillment of tasks with a detailed answer;

- methodological letters of the past;

- training computer program "Expert Unified State Examination";

- training tasks from the open segment of the federal bank of test materials;

2. Tasks with a detailed answer in the system of control measuring materials for the unified state exam
in chemistry

In the KIM USE system in chemistry, an important role is assigned to tasks with a detailed answer, which provide for a comprehensive check of the assimilation at a high level of complexity of several (two or more) content elements from various content blocks of the course in general, inorganic and organic chemistry.

Verification of the fulfillment of such tasks can be carried out only through an independent examination and on the basis of a specially developed standardized assessment system, which makes it possible to minimize differences in the opinions of experts on the assessment of the performance of the same work.

The creation of a standardized system for assessing the performance of tasks with a detailed answer within the framework of the unified state examination in chemistry assumed:

- determination of the basic requirements for tasks of this type;

- identification of the typology of the main elements of content and educational activities, verified by these tasks;

- determination of criteria and scales for assessing the performance of tasks of this type;

- development of a methodology for training experts who check the fulfillment of tasks with a detailed answer.

The description of the methodology for the standardized assessment of this type of assignments, which is necessary to ensure the objectivity of the USE assessment procedures, is the main purpose of the proposed methodological recommendations.

Purpose and features of tasks with a detailed answer

In the examination work, the tasks with a detailed answer are the smallest (there are only 5 of them in each variant of the work). Along with the fact that they comprehensively check the assimilation of the most complex elements of content from the content blocks: "Theoretical Foundations of Chemistry" (content line "Chemical Reaction"), "Methods of cognition in chemistry. Chemistry and Life ", these tasks are focused on testing skills that meet the requirements of the educational standard profile level:

– explain conditionality of the properties and use of substances by their composition and structure; the nature of the mutual influence of atoms in molecules of organic compounds; the relationship between inorganic and organic substances; the essence and regularity of the studied types of reactions;

– conduct combined calculations using chemical equations.

The combination of the checked content elements in tasks with a detailed answer is carried out in such a way that already in their condition the need can be traced: sequential execution of several interrelated actions, identification of cause-and-effect relationships between elements of the content, formulation of the answer in a certain logic and with the argumentation of individual provisions. Hence, it becomes obvious that completing tasks with a detailed answer requires a graduate to have solid theoretical knowledge, as well as developed skills to apply this knowledge in various educational situations, consistently and logically build an answer, draw conclusions and conclusions, give arguments in favor of the stated point of view, etc. NS.

Tasks with a detailed answer offered in the examination work have varying degrees of difficulty and involve checking from 3 to 5 answer elements. Each individual element of the response is graded
1 point, so the maximum score for a correctly completed assignment is from 3 to 5 points (depending on the degree of difficulty of the assignment). Testing of tasks is carried out by an expert based on the analysis of the performance of the task by the examinee and its comparison with the elements of the answer proposed in the criteria for assessing the task.

It is important to take into account that the content of the detailed answer assignments in many cases can orient the examinees to use different ways of completing them. This applies, first of all, to the methods of solving computational problems. Therefore, the instructions for assessing the performance of tasks should be considered in relation to the answer option proposed by the examinee.

All of the above features of tasks with a detailed answer allow us to conclude that they are designed to test the proficiency of skills that meet the highest requirements for the level of training of graduates and can serve as an effective means of differentiated assessment of the achievements of each of them.

Key Content Elements assessed by Long Answer Assignments

When selecting content for tasks with a detailed answer, it is first taken into account which elements of content and skills are the most important and meet the requirements of the educational standard of the profile level for the preparation of secondary (full) school graduates. These content elements included, in particular: redox reactions, structure of substances, mutual influence of atoms in molecules, mechanisms of reactions in organic chemistry, genetic relationship between classes of inorganic and organic compounds, calculations by chemical formulas and reaction equations.

When performing tasks, the examinee must demonstrate an understanding of the essence of the unity of the world of substances, the mechanisms of reactions, possession of the ability to compose reaction equations, apply knowledge about the properties of substances of various classes, structural features of substances, etc. A large role is assigned to computational problems in chemistry. This is due to the fact that when solving them, it is necessary to rely on knowledge of the chemical properties of compounds, to use the ability to draw up the equations of chemical reactions, i.e. use a theoretical framework and certain operational logic and computational skills.

In the examination work, tasks are used related to the implementation of all types of chemical calculations, which are presented in the curriculum not only for secondary (complete), but also for basic school (see Appendix 1).

The approach to the selection of the content of tasks with a detailed answer, which has positively proven itself in the process of the USE, has been retained in relation to the content of the examination work in 2016.

Municipal budgetary educational institution

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

Features of the solution and assessment of tasks 30-35 USE in chemistry

Prepared by: Arnautova Natalia Zakharovna,

chemistry and biology teacher

MBOU "School No. 4, Shebekino, Belgorod Region"

2017 year

Methodology for assessing tasks with a detailed answer (the main approaches to determining the criteria and the scale for assessing the performance of tasks)

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

Verification and assessment 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 answers of the examinees.

The use of the method of element-by-element analysis makes it necessary to ensure a clear correspondence of the formulation of the condition of the task to the checked elements of the content. The list of content elements tested by any assignment is consistent with the requirements of the standard for the level of preparation of high school graduates.

The criterion for assessing the performance of the task by the method of element-by-element analysis is to establish the presence in the answers of the examined elements of the answer given
in the response model. However, another answer model proposed by the examinee can be accepted, if it does not distort the essence of the chemical component of the task condition.

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

The level of complexity of the content being checked;

A certain sequence of actions that should be carried out when completing the task;

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

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

Approximately the same difficulty level for each of the content items tested by the assignment.

When developing the assessment criteria, the features of the content elements of all five tasks with a detailed answer, included in the examination work, are taken into account. It takes into account the fact that the records of the answers of the examinees can be either very general, streamlined and not specific, or unnecessarily short.
and insufficiently reasoned. Close attention is paid to highlighting the one-point response elements. 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 compiling a scale for assessing computational problems (33 and 34), the possibility of various ways of solving them is taken into account, and therefore, the presence in the examiner's answer of the main stages and results of the tasks indicated
in the evaluation criteria. Let us illustrate the methodology for evaluating tasks with a detailed answer using specific examples.

2017-2018 academic year

Tasks

Maximum score

Quest level

Task 30

2016-2017 year

Tasks 30 are focused on testing the skills to determine the oxidation state of chemical elements, determine the oxidizing agent and the reducing agent, predict the products of redox reactions, establish the formulas of substances missing in the reaction scheme, draw up an electronic balance, and use it to arrange the coefficients in the reaction equations.

The grading scale for such tasks includes the following elements:

 an electronic balance has been drawn up - 1 point;

 the indicated oxidizing agent and reducing agent - 1 point.

 formulas of missing substances are defined and coefficients are set
in the equation of the redox reaction - 1 point.

Job example:

Using the electronic balance method, write the reaction equation

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

Determine the oxidizing agent and 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 the oxidation state +7 (or potassium permanganate due to manganese
in the oxidation state +7) - an 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 oxidation state of the elements, which are respectively an oxidizing agent and a reducing agent in the reaction, has been determined;

the processes of oxidation and reduction are recorded, and on their basis an electronic (electronic-ionic) balance is drawn up;

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

Maximum score

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

2018 format assignments

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 the substances between which a redox reaction is possible, and write down the equation of this reaction. Make an electronic balance, indicate the oxidizing agent and the reducing agent.

Explanation.

Let's write the reaction equation:

Let's compose an electronic balance:

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

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

the processes of oxidation and reduction are recorded, and on their basis an electronic (electronic-ionic) balance is drawn up; which are respectively an oxidizing agent and a reducing agent in the reaction;

Only one of the above response elements was mistaken

Errors have been made in two of the above response elements

All response elements are written incorrectly

Maximum score

2018 format assignments

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 the substances between which the ion exchange reaction is possible. Write down the molecular, full, and abbreviated ionic equation for this reaction.

Explanation.

Possible answer:

Task 32. 2018 format assignments

In the condition of assignment 32, who tests the knowledge of the genetic relationship of various classes of inorganic substances, a description of a specific chemical experiment is proposed, the course of which the examinees will have to illustrate by means of the equations of the corresponding chemical reactions. The assessment scale for the task remains, as in 2016, equal to 4 points: each correctly written reaction equation is estimated at 1 point.

Job example:

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

Write the equations for the four reactions described.

Correct answer content and grading guidelines(other formulations of the answer are allowed that do not distort its meaning)

Points

Possible answer

Four equations of 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 the reaction equations is considered an error. No score is given for this equation.

Task 33. 2018 format assignments

Tasks 33 check the assimilation of knowledge about the relationship of organic substances and provide for checking five elements of the content: the correctness of writing five reaction equations corresponding to the scheme - the "chain" of transformations. When writing down the reaction equations, examinees must use the structural formulas of organic substances. The presence of each checked content element in the answer is estimated at 1 point. The maximum number of points for completing such tasks is 5.

Job example:

Write down the reaction equations with which you can carry out the following transformations:

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

Correct answer content and grading guidelines
other formulations of the answer are allowed that do not distort its meaning)

Points

Possible answer

Five reaction equations are written, corresponding to the transformation scheme:

Correctly written five equations of reactions

The four reaction equations are written correctly

Three reaction equations are written correctly

Two reaction equations are written correctly

Correctly written one reaction equation

All response elements are written incorrectly

Maximum score

Note that in the examiner's answer, it is permissible to use different types of structural formulas (expanded, abbreviated, skeletal), which unambiguously reflect the order of atomic bonds and the mutual arrangement of substituents and functional groups.
in a molecule of organic matter.

Task 34. 2018 format assignments

Tasks 34 are computational 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. These actions include the following:

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

- performing the calculations necessary to find answers to the
questions in the problem statement;

- the formulation of a logically justified answer to all the questions posed in the statement of work (for example, to establish a molecular formula).

However, it should be borne in mind that not all of the above actions must necessarily be present in the solution of any computational problem, and in some cases, some of them can be used repeatedly.

The maximum mark for the task is 4 points. When checking, you should first of all pay attention to the logical rationale of the actions performed, since some tasks can be solved in several ways. At the same time, in order to objectively assess 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.

Job example:

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

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

Points

Possible answer

The reaction equations are composed:

The amount of hydrogen sulfide substance 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:

in the answer, the reaction equations corresponding to the condition of the task are correctly written;

the calculations have been made correctly, in which the necessary physical quantities specified in the task condition are used;

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

in accordance with the condition of the task, the desired physical quantity is determined

Only one of the above response elements was mistaken

All response elements are written incorrectly

Maximum score

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

Task 35. 2018 format assignments

Tasks 35 provide for the determination of the molecular formula of a substance. The fulfillment of this task includes the following sequential operations: carrying out the calculations necessary to establish the molecular formula of an organic substance, recording the molecular formula of an organic substance, drawing up a structural formula of a substance that unambiguously reflects the order of bonds between atoms in its molecule, recording a reaction equation that meets the condition 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 the elements of the content being checked - calculations, on the basis of which they come to the definition of the molecular formula of the substance, the compilation of the general formula of the substance, and then - the determination on its basis of the molecular and structural formula of the substance.

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

Job example:

Burning a sample of some organic compound weighing 14.8 g yielded 35.2 g of carbon dioxide and 18.0 g of water.

It is known that the relative density of vapors of this substance in terms of hydrogen is 37. In the course of studying the chemical properties of this substance, it was found that when this substance interacts with copper (II) oxide, a ketone is formed.

Based on the given conditions of the assignment:

1) make the calculations necessary to establish the molecular formula of organic matter (indicate the units of measurement of the desired physical quantities);

write down the molecular formula of the original organic matter;

2) make up the structural formula of this substance, which unambiguously reflects the order of the 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.

Correct answer content and grading guidelines

(other formulations of the answer are allowed that do not distort its meaning)

Points

Possible answer

Found the amount of substance of combustion products:

General formula of substance - C x H y O z

n (CO 2) = 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 has been 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 ist (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 was 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 recorded;

the structural formula of an organic substance is written down, which reflects the order of bonds and the mutual arrangement of substituents and functional groups in the molecule in accordance with the condition of the task;

the equation of the reaction is written, which is indicated in the condition of the task, using the structural formula of organic matter

Only one of the above response elements was mistaken

Errors have been made in two of the above response elements

Errors were made in three of the above response elements

All response elements are written incorrectly

All response elements are written incorrectly

Maximum score

TOTAL part 2

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

Bibliography

1. Methodological materials for the chairmen and members of the subject commissions of the constituent entities of the Russian Federation on checking the fulfillment of tasks with a detailed answer to the examinations of the USE in 2017. Article "Methodological recommendations for assessing the performance of USE tasks with a detailed question." Moscow, 2017.

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

3. Demos, specifications, codifiers for the exam in 2018. FIPI website.

4.Certificate of planned changes in CMM 2018. FIPI website.

5. Site "I will solve the Unified State Examination": chemistry, for an expert.

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

1. In tasks of the basic level of difficulty(former 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 given degree of accuracy;
As with the other basic level assignments, these assignments will score 1 primary point.

2. Assignments of the advanced level (former part B) will be represented by one type: compliance assignments... They will be evaluated at 2 points (if there is one error - 1 point);

3. From the tasks of the basic level to the higher level, the question on the topic was moved: "Reversible and irreversible chemical reactions. Chemical equilibrium. Equilibrium shift under the influence of various factors."
At the same time, the issue of nitrogen-containing compounds will be checked at the baseline.

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