In our last article, we talked about the general codifiers of the Unified State Exam in Chemistry 2018 and how to properly start preparing for the Unified State Exam in Chemistry 2018. Now, we have to look at preparing for the exam in more detail. In this article we will look at simple tasks (previously called parts A and B) worth one and two points.

Simple tasks, called Basic in the 2018 Unified State Exam in Chemistry codifier, make up the largest part of the exam (20 tasks) in terms of the maximum primary score - 22 primary scores(tasks 9 and 17 are now worth 2 points).

Therefore, we must pay special attention to preparing for simple tasks in chemistry in the Unified State Exam 2018, taking into account the fact that many of them, with proper preparation, can be done correctly in 10 to 30 seconds, instead of the 2-3 minutes suggested by the organizers, which will allow save time for completing those tasks that are more difficult for the student.

The basic tasks of the Unified State Exam in chemistry 2018 include No. 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14,15, 16, 17, 20, 21, 27, 28, 29.

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Topics for assignments 1, 2, 3 and 4 in the Unified State Examination in Chemistry 2018

Aimed at testing knowledge related to the structure of atoms and molecules, the properties of atoms (electronegativity, metallic properties and atomic radius), the types of bonds formed when atoms interact with each other to form molecules (covalent non-polar and polar bonds, ionic bonds, hydrogen bonds etc.) the ability to determine the oxidation state and valence of an atom. To successfully complete these tasks in the Unified State Exam in Chemistry 2018 you need:

• Navigate in Periodic Table Dmitry Ivanovich Mendeleev;
• Study classical atomic theory;
• Know the rules for constructing the electronic configuration of an atom (Hund's rule, Pauli's principle) and be able to read electronic configurations of different notation forms;
• Understand the differences in the formation of different types of bonds (non-polar covalent is formed only between identical atoms, polar covalent between atoms of different chemical elements);
• Be able to determine the oxidation number of each atom in any molecule (oxygen always has an oxidation number of minus two (-2), and hydrogen plus one (+1))

Task 5 in the Unified State Exam in Chemistry 2018

Requires the student to have knowledge of the nomenclature of inorganic chemical compounds(rules for the formation of names of chemical compounds), both classical (nomenclatural) and trivial (historical).

Structure of tasks 6, 7, 8 and 9 of the Unified State Exam in chemistry

Aimed at testing knowledge about inorganic compounds and their chemical properties. To successfully complete these tasks in the Unified State Exam in Chemistry 2018 you need:

• It is not possible to know the classification of everyone organic compounds(non-salt-forming and salt-forming oxides (basic, amphoteric and acidic), etc.);

Tasks 12, 13, 14, 15 16 and 17 in the Unified State Exam

Test knowledge of organic compounds and their chemical properties. To successfully complete these tasks in the Unified State Exam in Chemistry 2018 you need:

• Know all classes of organic compounds (alkanes, alkenes, alkynes, arenes, etc.);
• Be able to name the compound using trivial and international nomenclature;
• Study the relationship between various classes of organic compounds, their chemical properties and methods of laboratory preparation.

Tasks 20 and 21 in the Unified State Exam 2018

Requires the student to know about chemical reactions, types of chemical reactions, and how to control chemical reactions.

Tasks 27, 28 and 29 in chemistry

This calculation problems. They contain protozoa chemical processes, which are aimed only at developing the student’s understanding of what happened in the task. The rest of the task is strictly mathematical. Therefore, to solve these tasks in the Unified State Exam in Chemistry 2018, you need to learn three basic formulas ( mass fraction, mole fraction by mass and volume) and be able to use a calculator.

Medium tasks, called Advanced in the 2018 Unified State Examination in Chemistry codifier (see Table 4 in the codifier - Distribution of tasks by difficulty level), constitute the lowest scoring part of the exam (9 tasks) in terms of the maximum primary score - 18 primary points or 30 %. Despite the fact that this is the smallest part of the exam, 5-7 minutes are planned for solving tasks, with highly trained They can be solved in 2-3 minutes, thereby saving time on tasks that are difficult for the student to solve.

Advanced tasks include tasks No. 10, 11, 18, 19, 22, 23, 24, 25, 26.

Chemistry assignment 10 2018

These are redox reactions. To successfully complete this task in the Unified State Exam in Chemistry 2018, you need to know:

• What are an oxidizing agent and a reducing agent and how do they differ?
• How to correctly determine the oxidation state of atoms in molecules and track which atoms changed the oxidation state as a result of the reaction.

Task 11 Unified State Exam in Chemistry 2018

Properties of inorganic substances. One of the most difficult tasks for a student to complete, due to the large number of possible answer combinations. Students often begin to describe ALL reactions, and in each task there are hypothetically from forty (40) to sixty (60), which takes a lot of time. To successfully complete this task in the Unified State Exam in Chemistry 2018 you need:

• Unmistakably determine which compound is in front of you (oxide, acid, base, salt);
• Know the basic principles of interclass interaction (an acid will not react with an acidic oxide, etc.);

Since this is one of the most problematic tasks, let's look at the solution to task No. 11 from demo versions of the Unified State Exam in chemistry 2018:

Eleventh task: Establish a correspondence between the formula of a substance and the reagents with each of which this substance can interact: for each position indicated by a letter, select the corresponding position indicated by a number.

Write down the selected numbers in the table under the corresponding letters.

Solution to task 11 in the Unified State Examination in Chemistry 2018

First of all, we need to determine what is offered to us as reagents: substance A - pure sulfur substance, B - sulfur oxide VI - acid oxide, C - zinc hydroxide - amphoteric hydroskid, D - zinc bromide - average salt. It turns out that there are 60 hypothetical reactions in this task. Very important for solving this task is the reduction of possible answer options, the main tool for this is the student’s knowledge of the main classes of inorganic substances and their interaction with each other, I propose to build the following table and cross out possible answer options as you logically evaluate the task:

And now, using knowledge about the nature of substances and their interactions, we remove answer options that are definitely not correct, for example, answer B- acidic oxide, which means it does not react with acids and acid oxides, which means that answer options 4.5 are not suitable for us, since sulfur oxide VI is higher oxide, which means it will not react with oxidizing agents, pure oxygen and chlorine - remove answers 3,4. There remains only answer 2, which suits us completely.

Answer B- here you need to apply the opposite technique, to whom they react amphoteric hydroxides- both with bases and acids, and we see an answer option consisting only of these compounds - answer 4.

Answer D- the average salt contains bromine anion, which means adding a similar anion is pointless - we remove answer option 4, containing hydrobromic acid. We will also remove answer option 5 - since the reaction with bromine chloride is meaningless, two soluble salts(zinc chloride and barium bromide), which means the reaction is completely reversible. Answer option 2 is also not suitable, since we already have a salt solution, which means adding water will not lead to anything, and answer option 3 is also not suitable due to the presence of hydrogen, which is not capable of reducing zinc, which means the answer option remains 1. There remains an option

answer A- which can cause the greatest difficulties, which is why we left it for last, which the student should also do if difficulties arise, since two points are given for an advanced level task, and we allow for one error (in this case, the student will receive one point for exercise). For the right decision This element of the task requires a good understanding of the chemical properties of sulfur and simple substances accordingly, in order not to describe the entire course of the solution, the answer will be 3 (where all answers are also simple substances).

Reactions:

A)S + H 2 à H 2 S

S + Cl 2 à SCl 2

S + O 2 à SO 2

B)SO 3 + BaO à BaSO 4

SO 3 + H 2 O à H 2 SO 4

SO 3 + KOH à KHSO 4 // SO 3 + 2 KOH à K2SO4 + H2O

IN) Zn(OH) 2 + 2HBrà ZnBr 2 + 2H 2 O

Zn(OH) 2 + 2LiOHà Li 2 ZnO 2 + 2H 2 O // Zn(OH) 2 + 2LiOHà Li 2

Zn(OH) 2 + 2CH 3 COOHà (CH 3 COO) 2 Zn + 2H 2 O

G) ZnBr 2 + 2AgNO 3à 2AgBr↓ + Zn(NO 3) 2

3ZnBr 2 + 2Na 3 PO 4à Zn 3 (PO 4) 2 ↓ + 6NaBr

ZnBr 2 + Cl 2à ZnCl 2 + Br 2

Tasks 18 and 19 in the Unified State Exam in chemistry

A more complex format, including all the knowledge necessary to solve basic tasks №12-17 . Separately, we can highlight the need to know Markovnikov's rules.

Task 22 in the Unified State Exam in chemistry

Electrolysis of melts and solutions. To successfully complete this task in the Unified State Exam in Chemistry 2018, you need to know:

• Difference between solutions and melts;
• Physical foundations of electric current;
• Differences between melt electrolysis and solution electrolysis;
• Basic principles of products obtained as a result of electrolysis of a solution;
• Features of electrolysis of a solution of acetic acid and its salts (acetates).

Chemistry assignment 23

Hydrolysis of salts. To successfully complete this task in the Unified State Exam in Chemistry 2018, you need to know:

• Chemical processes that occur during the dissolution of salts;
• Due to what the solution environment is formed (acidic, neutral, alkaline);
• Know the colors of the main indicators (methyl orange, litmus and phenolphthalein);
• Learn the strengths and weak acids and grounds.

Task 24 in the Unified State Exam in chemistry

Reversible and irreversible chemical reactions. To successfully complete this task in the Unified State Exam in Chemistry 2018, you need to know:

• Be able to determine the amount of substance in a reaction;
• Know the main factors influencing the reaction (pressure, temperature, concentration of substances)

Chemistry assignment 25 2018

Qualitative reactions to inorganic substances and ions.

To successfully complete this task in the Unified State Exam in Chemistry 2018, you need to learn these reactions.

Chemistry assignment 26

Chemical laboratory. The concept of metallurgy. Production. Chemical pollution environment. Polymers. To successfully complete this task in the Unified State Exam in Chemistry 2018, you need to have an understanding of all the elements of the task regarding a variety of substances (it is best to study together with chemical properties etc.)

Once again I would like to note that necessary for successful passing the Unified State Exam in chemistry in 2018, the theoretical bases have remained virtually unchanged, which means that all the knowledge that your child received at school will help him pass the chemistry exam in 2018.

In ours, your child will receive All theoretical materials necessary for preparation, and in the classroom will consolidate the acquired knowledge for successful implementation everyone exam assignments. The best teachers who have passed a very large competition and difficult tasks will work with him. entrance examinations. Classes are held in small groups, which allows the teacher to devote time to each child and formulate his individual implementation strategy exam paper.

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In the next article we will talk about the features of the solution difficult tasks Unified State Examination in chemistry and methods of production maximum quantity points when passing the Unified State Exam 2018.

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 tasks high level).
The maximum number of primary points remains the same: 64.
However, some changes will be made:

1. In tasks of basic difficulty level (former part A) will be included:
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. A question on the topic: “Reversible and irreversible chemical reactions” has been moved from basic level tasks to advanced ones. Chemical equilibrium. Shifting equilibrium under the influence of various factors."
However, the issue of nitrogen-containing compounds will be checked at a basic level.

4. Time unified exam in chemistry will be increased from 3 hours to 3.5 hours(from 180 to 210 minutes).

Let's look at the tasks presented in the exam paper by turning to demo version Unified State Exam in Chemistry 2019

Block “Structure of the atom. Periodic Law and Periodic Table of Chemical Elements D.I. Mendeleev. Patterns of changes in the properties of chemical elements by periods and groups.” “Structure of matter. Chemical bond"

This block contains tasks of only a basic level of complexity, which were aimed at testing the assimilation of concepts characterizing the structure of atoms of chemical elements and the structure of substances, as well as testing the ability to apply the Periodic Law to compare the properties of elements and their compounds.

Let's look at these tasks.

Tasks 1-3 are united by a single context:

Task 1

Determine which atoms of the elements indicated in the series in the ground state have four electrons in the outer energy level.

Write down the numbers of the selected elements in the answer field.

To perform tasks 1 it is necessary to apply knowledge about the structure of the electronic shells of atoms of chemical elements of the first four periods, s-, p- And d- elements, about electronic configurations of atoms, ground and excited states of atoms. The elements presented are in the main subgroups, therefore the number of outer electrons of their atoms is equal to the number of the group in which the element is located. The silicon and carbon atoms have four outer electrons.

In 2018, 61.0% of examinees successfully completed task 1.

The manual contains training tasks for basic and increased levels difficulties grouped by topic and type. The tasks are arranged in the same sequence as proposed in the exam version of the Unified State Exam. At the beginning of each assignment type, there are content elements to be tested—topics that you should study before starting. The manual will be useful for chemistry teachers, as it makes it possible to effectively organize educational process in class, conducting current control knowledge, as well as preparing students for the Unified State Exam.

In 2-3 months it is impossible to learn (repeat, improve) such a complex discipline as chemistry.

There are no changes to the KIM Unified State Exam 2020 in chemistry.

Don't put off preparing for later.

1. When starting to analyze tasks, first study theory. The theory on the site is presented for each task in the form of recommendations on what you need to know when completing the task. will guide you in the study of basic topics and determine what knowledge and skills will be required when completing Unified State Examination tasks in chemistry. For successful completion Unified State Exam in Chemistry - theory is most important.
2. The theory needs to be supported practice, constantly solving problems. Since most of the mistakes are due to the fact that I read the exercise incorrectly and did not understand what is required in the task. The more often you decide subject tests, the faster you will understand the structure of the exam. Training tasks developed based on demo versions from FIPI give such an opportunity to decide and find out the answers. But don't rush to peek. First, decide for yourself and see how many points you get.

Points for each chemistry task

• 1 point - for tasks 1-6, 11-15, 19-21, 26-28.
• 2 points - 7-10, 16-18, 22-25, 30, 31.
• 3 points - 35.
• 4 points - 32, 34.
• 5 points - 33.

Total: 60 points.

Structure of the examination paper consists of two blocks:

1. Questions requiring a short answer (in the form of a number or a word) - tasks 1-29.
2. Problems with detailed answers – tasks 30-35.

3.5 hours (210 minutes) are allotted to complete the examination paper in chemistry.

There will be three cheat sheets on the exam. And you need to understand them

This is 70% of the information that will help you pass the chemistry exam successfully. The remaining 30% is the ability to use the provided cheat sheets.

• If you want to get more than 90 points, you need to spend a lot of time on chemistry.
• To successfully pass the Unified State Exam in chemistry, you need to solve a lot: training tasks, even if they seem easy and of the same type.
• Distribute your strength correctly and do not forget about rest.

Dare, try and you will succeed!