The most difficult tasks of the oge in chemistry. Collection of ideal social studies essays

Chemistry. A new complete guide to preparing for the OGE. Medvedev Yu.N.

M.: 2017. - 320 p.

The new handbook contains all the theoretical material on the course of chemistry required to pass the main state exam in the 9th grade. It includes all elements of the content, checked by control and measuring materials, and helps to generalize and systematize knowledge and skills for the course of the secondary (complete) school. The theoretical material is presented in a concise and accessible form. Each topic is accompanied by examples of test tasks. Practical tasks correspond to the OGE format. Answers to the tests are given at the end of the manual. The manual is addressed to schoolchildren and teachers.

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CONTENT
From author 10
1.1. The structure of the atom. The structure of the electron shells of atoms of the first 20 elements of the Periodic Table D.I. Mendeleeva 12
The nucleus of an atom. Nucleons. Isotopes 12
Electronic shells 15
Electronic configurations of atoms 20
Tasks 27
1.2. Periodic law and Periodic system of chemical elements D.I. Mendeleev.
The physical meaning of the serial number of the chemical element 33
1.2.1. Groups and periods of the Periodic system 35
1.2.2. Patterns of changes in the properties of elements and their compounds in connection with the position in the Periodic system of chemical elements 37
Changing the properties of elements in the main subgroups. 37
Changing element properties by period 39
Tasks 44
1.3. The structure of molecules. Chemical bond: covalent (polar and non-polar), ionic, metallic 52
Covalent bond 52
Ionic bond 57
Metal connection 59
Tasks 60
1.4. Valency of chemical elements.
The degree of oxidation of chemical elements 63
Tasks 71
1.5. Pure substances and mixtures 74
Tasks 81
1.6. Simple and complex substances.
The main classes of inorganic substances.
Nomenclature of inorganic compounds 85
Oxides 87
Hydroxides 90
Acids 92
Salts 95
Tasks 97
2.1. Chemical reactions. Conditions and signs of chemical reactions. Chemical
equations. Conservation of the mass of substances in chemical reactions 101
Tasks 104
2.2. Classification of chemical reactions
on various grounds: the number and composition of the starting and obtained substances, changes in the oxidation states of chemical elements,
absorption and release of energy 107
Classification according to the number and composition of reagents and final substances 107
Classification of reactions according to the change in the oxidation states of chemical elements HO
Classification of reactions according to the thermal effect 111
Tasks 112
2.3. Electrolytes and non-electrolytes.
Cations and anions 116
2.4. Electrolytic dissociation of acids, alkalis and salts (medium) 116
Electrolytic dissociation of acids 119
Electrolytic dissociation of bases 119
Electrolytic dissociation of salts 120
Electrolytic dissociation of amphoteric hydroxides 121
Tasks 122
2.5. Ion exchange reactions and conditions for their implementation 125
Examples of writing reduced ionic equations 125
Conditions for the implementation of ion exchange reactions 127
Tasks 128
2.6. Redox reactions.
Oxidizing and reducing agents 133
Classification of redox reactions 134
Typical reducing and oxidizing agents 135
Selection of coefficients in the equations of redox reactions 136
Tasks 138
3.1. Chemical properties of simple substances 143
3.1.1. Chemical properties of simple substances - metals: alkali and alkaline earth metals, aluminum, iron 143
Alkali metals 143
Alkaline earth metals 145
Aluminum 147
Iron 149
Tasks 152
3.1.2. Chemical properties of simple substances - non-metals: hydrogen, oxygen, halogens, sulfur, nitrogen, phosphorus,
carbon, silicon 158
Hydrogen 158
Oxygen 160
Halogens 162
Sulfur 167
Nitrogen 169
Phosphorus 170
Carbon and silicon 172
Tasks 175
3.2. Chemical properties of complex substances 178
3.2.1. Chemical properties of oxides: basic, amphoteric, acidic 178
Basic oxides 178
Acid oxides 179
Amphoteric oxides 180
Tasks 181
3.2.2. Chemical properties of bases 187
Tasks 189
3.2.3. Chemical properties of acids 193
General properties of acids 194
Specific properties of sulfuric acid 196
Specific properties of nitric acid 197
Specific properties of phosphoric acid 198
Tasks 199
3.2.4. Chemical properties of salts (medium) 204
Tasks 209
3.3. The relationship of different classes of inorganic substances 212
Tasks 214
3.4. Initial information about organic substances 219
Main classes of organic compounds 221
Fundamentals of the theory of the structure of organic compounds ... 223
3.4.1. Limit and unsaturated hydrocarbons: methane, ethane, ethylene, acetylene 226
Methane and ethane 226
Ethylene and acetylene 229
Tasks 232
3.4.2. Oxygen-containing substances: alcohols (methanol, ethanol, glycerin), carboxylic acids (acetic and stearic) 234
Alcohols 234
Carboxylic acids 237
Tasks 239
4.1. Rules for safe work in the school laboratory 242
Rules for safe work in the school laboratory. 242
Laboratory glassware and equipment 245
Separation of mixtures and purification of substances 248
Preparation of solutions 250
Tasks 253
4.2. Determination of the nature of the environment of solutions of acids and alkalis using indicators.
Qualitative reactions to ions in solution (chloride, sulfate, carbonate ions) 257
Determination of the nature of the environment of solutions of acids and alkalis using indicators 257
Qualitative reactions to ions
in solution 262
Tasks 263
4.3. Qualitative reactions to gaseous substances (oxygen, hydrogen, carbon dioxide, ammonia).

Obtaining gaseous substances 268
Qualitative reactions to gaseous substances 273
Tasks 274
4.4. Carrying out calculations based on formulas and equations of reactions 276
4.4.1. Calculation of the mass fraction of a chemical element in a substance 276
Tasks 277
4.4.2. Calculating the mass fraction of a solute in a solution 279
Tasks 280
4.4.3. Calculation of the amount of a substance, mass or volume of a substance from the amount of a substance, mass or volume of one of the reagents
or reaction products 281
Calculating the amount of a substance 282
Mass calculation 286
Volume calculation 288
Tasks 293
Information about the two exam models of the OGE in chemistry 296
Instructions for the implementation of the experimental task 296
Samples of experimental tasks 298
Answers to tasks 301
Applications 310
Table of solubility of inorganic substances in water 310
Electronegativity of s- and p-elements 311
Electrochemical voltage series of metals 311
Some of the most important physical constants 312
Prefixes in the formation of multiple and submultiple units 312
Electronic configurations of atoms 313
The most important acid-base indicators 318
Geometric structure of inorganic particles 319

OGE in chemistry is given only at the choice of the student, this test is not included in the list of mandatory. Chemistry is chosen by students who, after the 9th grade, plan to enter the profile 10th grade of a school or a specialized college, technical school. For admission to medical school, it is required to pass not only chemistry, but also biology. The exam implies orientation in theory, its successful application in practice. The subject needs to solve a lot of tasks of different levels of complexity from a wide range of topics. To decide which topics to pay attention to, check out the OGE Preparation Program in Chemistry.

The exam consists of tasks, which are divided into two logical blocks:

The first part includes tasks for knowledge of the theory: here you need to give a short answer - a number, a sequence of numbers, a word.
In the second part, there are several questions to which you need to give detailed, complete answers, conduct a laboratory experiment, write conclusions, and perform calculations. It is extremely important to be able to use special equipment, to use algorithms for solving problems of different levels of complexity.

In 2018, the minimum threshold was 9 points - this is the minimum that will allow you to get a minimum grade and a certificate.
In the exam, the subject has tips: tables of the solubility of salts, acids, bases in water, the periodic table of Mendeleev, tables of stresses of metals. With the ability to use these materials, you can solve many tasks without difficulty.

The main advice that is relevant for every exam is to plan your study. Without a clear plan, you will not be able to achieve a high level of preparation. To make your planning as efficient as possible, check out- it indicates topics and sections that need special attention.
Evaluate your strengths: the easiest way is online testing. Upon passing the test, you get the result, and you can evaluate which types of tasks and topics cause you the most difficulty.
Once you have identified problematic topics, give them more attention than others. For training, take textbooks, reference books.
Be sure to solve problems! The more problems you solve for preparation, the easier it will be on the exam.
Ask questions: find a specialist who can help you in problem situations. It could be a tutor or a school teacher. Only a specialist can help you analyze your mistakes and not make them again.
Learn to use hints - those tables that you can take with you to the exam.
It is not enough to study theory, it is very important to train to pass tests. This form of knowledge testing causes difficulties for many, especially if it was not used in the lessons. Solve more test tasks of different types so that they do not cause fear and misunderstanding during the exam.
"I will solve the OGE in chemistry" will help you prepare for the exam and successfully pass it, rationally using the allotted time, without stress.

Part 1 contains 19 tasks with a short answer, including 15 tasks of a basic level of complexity (the serial numbers of these tasks: 1, 2, 3, 4, ... 15) and 4 tasks of an increased level of complexity (the serial numbers of these tasks: 16, 17, 18, 19). For all their differences, the tasks of this part are similar in that the answer to each of them is written briefly in the form of one digit or a sequence of digits (two or three). The sequence of numbers is written in the answer sheet without spaces and other additional characters.

Part 2, depending on the CMM model, contains 3 or 4 tasks of a high level of complexity, with a detailed answer. The difference between examination models 1 and 2 is in the content and approaches to the implementation of the last tasks of the examination options:

Exam Model 1 contains task 22, which involves performing a "thought experiment";

Exam model 2 contains tasks 22 and 23, which provide for the performance of laboratory work (a real chemical experiment).

Scale for converting points into grades:

"2"– from 0 to 8

"3"– from 9 to 17

"4"– from 18 to 26

"5"– from 27 to 34

The system for assessing the performance of individual tasks and the examination work as a whole

The correct performance of each of the tasks 1-15 is estimated at 1 point. The correct performance of each of the tasks 16-19 is estimated as a maximum of 2 points. Tasks 16 and 17 are considered completed correctly if two answers are correctly selected in each of them. For an incomplete answer - one of the two answers is correctly named or three answers are named, of which two are correct - 1 point is given. The rest of the answers are considered incorrect and are scored 0 points. Tasks 18 and 19 are considered completed correctly if three matches are correctly established. Partially correct is the answer in which two out of three matches are established; it is worth 1 point. The remaining options are considered incorrect answers and are scored 0 points.

Checking the tasks of part 2 (20–23) is carried out by the subject commission. The maximum score for a correctly completed task: for tasks 20 and 21 - 3 points each; in model 1 for task 22 - 5 points; in model 2 for task 22 - 4 points, for task 23 - 5 points.

To complete the examination work in accordance with model 1, 120 minutes are allotted; according to model 2 – 140 minutes

The state final certification of 2019 in chemistry for graduates of the 9th grade of general educational institutions is carried out in order to assess the level of general education of graduates in this discipline. The tasks test knowledge of the following sections of chemistry:

The structure of the atom.
Periodic law and Periodic system of chemical elements D.I. Mendeleev.
The structure of molecules. Chemical bond: covalent (polar and non-polar), ionic, metallic.
Valency of chemical elements. The degree of oxidation of chemical elements.
Simple and complex substances.
Chemical reaction. Conditions and signs of chemical reactions. Chemical equations.
Electrolytes and non-electrolytes. Cations and anions. Electrolytic dissociation of acids, alkalis and salts (medium).
Ion exchange reactions and conditions for their implementation.
Chemical properties of simple substances: metals and non-metals.
Chemical properties of oxides: basic, amphoteric, acidic.
Chemical properties of bases. Chemical properties of acids.
Chemical properties of salts (medium).
Pure substances and mixtures. Rules for safe work in the school laboratory. Chemical pollution of the environment and its consequences.
The degree of oxidation of chemical elements. Oxidizing agent and reducing agent. Redox reactions.
Calculation of the mass fraction of a chemical element in a substance.
Periodic law D.I. Mendeleev.
Initial information about organic substances. Biologically important substances: proteins, fats, carbohydrates.
Determination of the nature of the medium of a solution of acids and alkalis using indicators. Qualitative reactions to ions in solution (chloride, sulfate, carbonation, ammonium ion). Qualitative reactions to gaseous substances (oxygen, hydrogen, carbon dioxide, ammonia).
Chemical properties of simple substances. Chemical properties of complex substances.

Date of passing the OGE in chemistry 2019:
June 4 (Tuesday).

There are no changes in the structure and content of the examination paper in 2019 compared to 2018.

In this section you will find online tests that will help you prepare for passing the OGE (GIA) in chemistry. We wish you success!

The standard OGE test (GIA-9) of the 2019 format in chemistry consists of two parts. The first part contains 19 tasks with a short answer, the second part contains 3 tasks with a detailed answer. In this regard, only the first part (i.e., the first 19 tasks) is presented in this test. According to the current structure of the exam, among these tasks, only 15 answers are offered. However, for the convenience of passing the tests, the site administration decided to offer answers in all tasks. But for tasks in which answer options are not provided by the compilers of real control and measurement materials (KIMs), the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

The standard OGE test (GIA-9) of the 2018 format in chemistry consists of two parts. The first part contains 19 tasks with a short answer, the second part contains 3 tasks with a detailed answer. In this regard, only the first part (i.e., the first 19 tasks) is presented in this test. According to the current structure of the exam, among these tasks, only 15 answers are offered. However, for the convenience of passing the tests, the site administration decided to offer answers in all tasks. But for tasks in which answer options are not provided by the compilers of real control and measurement materials (KIMs), the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

The standard OGE test (GIA-9) of the 2017 format in chemistry consists of two parts. The first part contains 19 tasks with a short answer, the second part contains 3 tasks with a detailed answer. In this regard, only the first part (i.e., the first 19 tasks) is presented in this test. According to the current structure of the exam, among these tasks, only 15 answers are offered. However, for the convenience of passing the tests, the site administration decided to offer answers in all tasks. But for tasks in which answer options are not provided by the compilers of real control and measurement materials (KIMs), the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

The standard OGE test (GIA-9) of the 2016 format in chemistry consists of two parts. The first part contains 19 tasks with a short answer, the second part contains 3 tasks with a detailed answer. In this regard, only the first part (i.e., the first 19 tasks) is presented in this test. According to the current structure of the exam, among these tasks, only 15 answers are offered. However, for the convenience of passing the tests, the site administration decided to offer answers in all tasks. But for tasks in which answer options are not provided by the compilers of real control and measurement materials (KIMs), the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

The standard OGE test (GIA-9) of the 2015 format in chemistry consists of two parts. The first part contains 19 tasks with a short answer, the second part contains 3 tasks with a detailed answer. In this regard, only the first part (i.e., the first 19 tasks) is presented in this test. According to the current structure of the exam, among these tasks, only 15 answers are offered. However, for the convenience of passing the tests, the site administration decided to offer answers in all tasks. But for tasks in which answer options are not provided by the compilers of real control and measurement materials (KIMs), the number of answer options has been significantly increased in order to bring our test as close as possible to what you will have to face at the end of the school year.

When completing tasks A1-A19, select only one correct option.
When completing tasks B1-B3, select two correct options.

When completing tasks A1-A15, select only one correct option.

When completing tasks A1-A15, choose only one correct option.

■ Is there a guarantee that after classes with you we will pass the OGE in chemistry with the required score?

Over 80% ninth-graders who have completed a full course of preparation for the OGE and regularly completed their homework, passed this exam perfectly! And this despite the fact that even 7-8 months before the exam, many of them could not remember the formula of sulfuric acid and confused the solubility table with the periodic table!

■ Already January, knowledge of chemistry - at zero. Is it already too late or is there still a chance to pass the OGE?

There is a chance, but on condition that the student is ready to work seriously! I am not shocked by the zero level of knowledge. Moreover, most of the ninth graders are preparing for the OGE. But you need to understand that miracles do not happen. Without the active work of the student, knowledge "by itself" will not fit in the head.

■ Preparation for the OGE in chemistry - is it very hard?

First of all, it's very interesting! I cannot call the OGE in Chemistry a difficult exam: the tasks offered are quite standard, the range of topics is known, the evaluation criteria are "transparent" and logical.

■ How does the OGE exam in chemistry work?

There are two options for the OGE: with and without an experimental part. In the first version, students are offered 23 tasks, two of which are related to practical work. You have 140 minutes to complete the task. In the second option, 22 problems must be solved in 120 minutes. 19 tasks require only a short answer, the rest require a detailed solution.

■ How (technically) can I sign up for your classes?

Very simple!

Call me on the phone: 8-903-280-81-91 . You can call any day until 23.00.
We will arrange the first meeting for preliminary testing and determining the level of the group.
You choose the time of classes convenient for you and the size of the group (individual lessons, classes in pairs, mini-groups).
Everything, at the appointed time, work begins.

Good luck!

Or you can just use this site.

■ How best to prepare: in a group or individually?

Both options have their advantages and disadvantages. Classes in groups are optimal in terms of price-quality ratio. Individual lessons allow for a more flexible schedule, finer "tuning" of the course to the needs of a particular student. After preliminary testing, I will recommend you the best option, but the final choice is yours!

■ Do you make home visits to students?

Yes, I'm leaving. To any district of Moscow (including areas outside the Moscow Ring Road) and to the Moscow suburbs. At home, students can conduct not only individual, but also group classes.

■ And we live far from Moscow. What to do?

Practice remotely. Skype is our best assistant. Distance classes are no different from face-to-face: the same methodology, the same teaching materials. My login: repetitor2000. Contact us! Let's do a trial lesson - you will see how easy it is!

■ When can classes start?

Basically, at any time. The ideal option is one year before the exam. But even if there are several months left before the OGE, contact us! Perhaps there are still free "windows", and I can offer you an intensive course. Call: 8-903-280-81-91!

■ Does good preparation for the USE guarantee successful completion of the USE in chemistry in the eleventh grade?

Doesn't guarantee it, but contributes a lot to it. The foundation of chemistry is laid precisely in grades 8-9. If a student masters the basic sections of chemistry well, it will be much easier for him to study in high school and prepare for the exam. If you are planning to enter a university with a high level of requirements in chemistry (Moscow State University, leading medical universities), you should start preparing not a year before the exam, but already in grades 8-9!

■ How much will OGE-2019 in chemistry differ from OGE-2018?

No changes are planned. There are two versions of the exam: with or without a practical part. The number of tasks, their topics, and the grading system remain the same as they were in 2018.