Preparation for the exam in chemistry from scratch. Unified State Exam
The textbook contains material for preparing for the Unified State Exam in chemistry.
43 topics of the Unified State Exam program are presented, tasks for which correspond to basic (28), advanced (10) and high (5) levels of complexity. The entire theory is structured in accordance with the topics and issues of the content of control measurement materials.
Each topic contains theoretical principles, questions and exercises, tests of all types (single-choice, matching, multiple-choice or number-based), and tasks with a detailed answer.
Addressed to teachers and students of senior secondary schools, as well as university applicants, teachers and students of chemical faculties (schools) of pre-university training.
Examples.
Samples of metals are given: lead - copper - mercury - sodium - gold - silver - tungsten.
Identify these metals by physical characteristics:
a) very soft (cut with a knife);
b) painted yellow;
c) has a matte surface;
d) has the greatest refractoriness;
e) liquid at room temperature;
f) painted red;
g) has a metallic luster and high electrical conductivity.
Copper samples were obtained from the starting substances: red Cu2O, black CuO, white CuSO4, blue CuSO4 5H2O, dark green Cu2CO3(OH)2 and yellow-brown CuCl2. Should (yes, no) the resulting copper samples be different:
a) by color,
b) by melting point,
c) by the ability to become covered with a black-green coating in city air?
CONTENT
PREFACE 7
1. Theoretical sections of chemistry
1.1. Modern ideas about the structure of the atom 8
1.2. Periodic Law and Periodic Table of Chemical Elements D.I. Mendeleeva 17
1.2.1. Patterns of changes in the chemical properties of elements and their compounds by periods and groups 17
1.2.2-1.2.3. General characteristics of metals of the main subgroups of groups I-III and transition elements (copper, zinc, chromium, iron) according to their position in the Periodic Table
system and structural features of their atoms 24
1.2.4. General characteristics of main nonmetals
subgroups of groups IV-VII according to their position in the Periodic Table and the structural features of their atoms 30
1.3. Chemical bonding and structure of matter 44
1.3.1. Covalent bond, its varieties and mechanisms of formation. Polarity and energy of covalent bonds. Ionic bond. Metal connection. Hydrogen bond 44
1.3.2. Electronegativity and oxidation state of chemical elements. Valence of atoms 52
1.3.3. Substances of molecular and non-molecular structure. Type of crystal lattice. Dependence of the properties of substances on their composition and structure 59
1.4. Chemical reaction 68
1.4.1-1.4.2. Classification of reactions in inorganic and organic chemistry. Thermal effect of the reaction. Thermochemical Equations 68
1.4.3. Reaction speed, its dependence on various factors 80
1.4.4. Reversible and irreversible reactions. Chemical balance. Shift of equilibrium under the influence of various factors 88
1.4.5. Dissociation of electrolytes in aqueous solutions. Strong and weak electrolytes 98
1.4.6. Ion exchange reactions 108
1.4.7. Hydrolysis of salts. Aqueous solution environment: acidic, neutral, alkaline 115
1.4.8. Redox reactions. Corrosion of metals and methods of protection against it 128
1.4.9. Electrolysis of melts and solutions (salts, alkalis, acids) 144
2. Inorganic chemistry
2.1. Classification of inorganic substances. Nomenclature of inorganic substances (trivial and international) 149
2.2. Characteristic chemical properties of simple substances - metals: alkali, alkaline earth, aluminum, transition metals - copper, zinc, chromium, iron 170
2.3. Characteristic chemical properties of simple substances - nonmetals: hydrogen, halogens, oxygen, sulfur, nitrogen, phosphorus, carbon, silicon 177
2.4. Characteristic chemical properties of oxides: basic, amphoteric, acidic 189
2.5-2.6. Characteristic chemical properties of bases, amphoteric hydroxides and acids 193
2.7. Characteristic chemical properties of salts: medium, acidic, basic, complex (using the example of aluminum and zinc compounds) 199
2.8. Interrelation of various classes of inorganic substances 202
3. Organic chemistry
3.1-3.2. Theory of the structure of organic compounds: homology and isomerism (structural and spatial). Hybridization of carbon 205 atomic orbitals
3.3. Classification of organic compounds. Nomenclature of organic compounds (trivial and international). Radical. Functional group 213
3.4. Characteristic chemical properties of hydrocarbons: alkanes, cycloalkanes, alkenes, dienes, alkynes, aromatic hydrocarbons (benzene and toluene) 220
3.5. Characteristic chemical properties of saturated monohydric and polyhydric alcohols, phenol 239
3.6. Characteristic chemical properties of aldehydes, saturated carboxylic acids, esters 247
3.7. Characteristic chemical properties of nitrogen-containing organic compounds: amines, amino acids 255
3.8. Biologically important compounds: fats, proteins, carbohydrates (mono-, di- and polysaccharides) 259
3.9. Relationship between organic compounds 267
4. Methods of knowledge in chemistry. Chemistry and life
4.1. Experimental Fundamentals of Chemistry 272
4.1.1-4.1.2. Rules for working in the laboratory. Methods for separating mixtures and purifying substances 272
4.1.3-4.1.5. Determination of the nature of the medium of aqueous solutions of substances. Indicators. Qualitative reactions to inorganic substances and ions. Identification of organic compounds 272
4.1.6. The main methods of obtaining (in the laboratory) specific substances belonging to the studied classes of inorganic compounds 284
4.1.7. The main methods for producing hydrocarbons (in the laboratory) 286
4.1.8. The main methods for obtaining oxygen-containing organic compounds (in the laboratory) 292
4.2. General ideas about industrial methods for obtaining essential substances 298
4.2.1. The concept of metallurgy: general methods for producing metals 298
4.2.2. General scientific principles of chemical production (using the example of the production of ammonia, sulfuric acid, methanol). Chemical pollution of the environment and its consequences 300
4.2.3. Natural sources of hydrocarbons, their processing 302
4.2.4. High molecular weight compounds. Polymerization and polycondensation reactions. Polymers. Plastics, rubbers, fibers 303
4.3. Calculations using chemical formulas and reaction equations 311
4.3.1-4.3.2. Calculations of volumetric ratios of gases and thermal effect in reactions 311
4.3.3. Calculation of the mass of solute contained in a certain mass of solution with a known mass fraction 315
4.3.4. Calculation of the mass of a substance or volume of gases from a known amount of a substance, mass or volume of one of the substances participating in the reaction 321
4.3.5-4.3.8. Calculations: mass (volume, amount of substance) of the reaction product, if one of the substances is given in excess (has impurities) or in the form of a solution with a certain mass fraction of the substance; practical yield of the product, mass fraction (mass) of the substance in the mixture 324
4.3.9. Calculations to find the molecular formula of a substance 328
Answers to tasks for independent work 333
APPLICATIONS 350.
Preparation for the Unified State Exam in Chemistry is, as a rule, preparation for the Unified State Exam in Chemistry from scratch.
The curriculum in ordinary schools is structured in such a way that the hours allocated for chemistry are absolutely not enough to begin to understand something.
Students remember only a few templates from the school curriculum. For example: “The reaction proceeds to completion if gas, sediment or water is obtained.” But what kind of reaction, what kind of sediment - none of the high school students know! At school they don’t go into these details. And in the end, even behind the apparent success, behind the A’s in school, there is no understanding.
When preparing for the Unified State Exam in chemistry from scratch, it is worth starting with the most ordinary school textbooks for the eighth and ninth grade. Yes, the textbook does not provide the proper level of explanation that is needed to understand what is happening. Be prepared that you will simply have to memorize some of the information.
If you are preparing for the Unified State Exam in chemistry from scratch and reading a school textbook, you are learning chemistry like a foreign language. After all, in a foreign language at the beginning of learning there are also some incomprehensible words, incomprehensible letters. And you need to spend some time and effort on studying the “alphabet” and basic “dictionary”, otherwise nothing will work out further.
Chemistry is an empirical science, and this is what distinguishes it from mathematics. We are dealing with facts that we are trying to explain. First we become familiar with a certain fact, and when it is beyond doubt, we explain it. There are a lot of facts in chemistry, and it is difficult to understand them if you are preparing for the Unified State Exam in chemistry from scratch. Therefore, we start with an ordinary school textbook. For example, a textbook, the authors of which are G. E. Rudzitis and F. G. Feldman, or N. E. Kuzmenko, V. V. Lunin, V. V. Eremin.
And after that we need to move on to serious books. Because if you are preparing for the Unified State Exam in chemistry from scratch, trying to “jump” straight into a serious book may end in failure. At the same time, school textbooks alone will not be enough to prepare for the Unified State Exam in chemistry!
I wrote a guide to prepare for the Unified State Exam in chemistry. It's called “Chemistry. Author’s course of preparation for the Unified State Exam.” This is a book for those who have already read school textbooks, who do not need to be told from scratch what valence is and what symbol denotes what element.
Another piece of advice for those who are preparing for the Unified State Exam in chemistry from scratch.
In this situation, there is no point in “spraying” on the Olympiads, because there will be almost no chance of solving anything there. If you started preparing in advance, and by the beginning of 11th grade you are writing test exams in chemistry worth 70 points, then it makes sense to participate. It is worth studying the individual sections of physical chemistry that are needed for the Olympiad and trying your hand.
But what to do if a high school student wants to prepare for the Unified State Exam in chemistry from scratch and does not understand the school textbook? Can't understand! He wants to become a doctor, but he doesn’t understand the school textbook. What then? Go to a tutor?
You can try taking a different school textbook. They are all written in different languages and have slightly different approaches. But if a high school student decides to prepare for the Unified State Exam in chemistry from scratch and cannot master a single textbook on school chemistry for the 8th grade... Maybe then it’s worth thinking about a specialty that is easier to cope with? Such an applicant will spend a lot of effort on admission, but if he passes, then, most likely, it will be a paid one, and then he will also drop out! After all, studying in medical school is much harder than preparing for the Unified State Exam for admission to medical school. If preparing for the Unified State Exam in chemistry causes insoluble difficulties, absolutely insurmountable ones, then studying in medicine will be much more difficult! Remember this when preparing for the Unified State Exam in Chemistry from scratch.
M.: 2013. - 352 p.
The textbook contains material for preparing for the Unified State Exam in chemistry. 43 topics of the Unified State Exam program are presented, tasks for which correspond to basic (28), advanced (10) and high (5) levels of complexity. The entire theory is structured in accordance with the topics and issues of the content of control measurement materials. Each topic contains theoretical principles, questions and exercises, tests of all types (single-choice, matching, multiple-choice or number-based), and tasks with a detailed answer. Addressed to teachers and students of senior secondary schools, as well as university applicants, teachers and students of chemical faculties (schools) of pre-university training.
Format: pdf
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CONTENT
PREFACE 7
1. Theoretical sections of chemistry
1.1. Modern ideas about the structure of the atom 8
1.2. Periodic Law and Periodic Table of Chemical Elements D.I. Mendeleeva 17
1.2.1. Patterns of changes in the chemical properties of elements and their compounds by periods and groups 17
1.2.2-1.2.3. General characteristics of metals of the main subgroups of groups I-III and transition elements (copper, zinc, chromium, iron) according to their position in the Periodic Table and the structural features of their atoms 23
1.2.4. General characteristics of non-metals of the main subgroups of groups IV-VII according to their position in the Periodic Table and the structural features of their atoms 29
1.3. Chemical bonding and structure of matter 43
1.3.1. Covalent bond, its varieties and mechanisms of formation. Polarity and energy of covalent bonds. Ionic bond. Metal connection. Hydrogen bond 43
1.3.2. Electronegativity and oxidation state of chemical elements. Valence of atoms 51
1.3.3. Substances of molecular and non-molecular structure. Type of crystal lattice. Dependence of the properties of substances on their composition and structure 57
1.4. Chemical reaction 66
1.4.1-1.4.2. Classification of reactions in inorganic and organic chemistry. Thermal effect of the reaction. Thermochemical Equations 66
1.4.3. Reaction speed, its dependence on various factors 78
1.4.4. Reversible and irreversible reactions. Chemical balance. Shift of equilibrium under the influence of various factors 85
1.4.5. Dissociation of electrolytes in aqueous solutions. Strong and weak electrolytes 95
1.4.6. Ion exchange reactions 106
1.4.7. Hydrolysis of salts. Aqueous solution environment: acidic, neutral, alkaline 112
1.4.8. Redox reactions. Corrosion of metals and methods of protection against it 125
1.4.9. Electrolysis of melts and solutions (salts, alkalis, acids) 141
2. Inorganic chemistry
2.1. Classification of inorganic substances. Nomenclature of inorganic substances (trivial and international) 146
2.2. Characteristic chemical properties of simple substances - metals: alkali, alkaline earth, aluminum, transition metals - copper, zinc, chromium, iron 166
2.3. Characteristic chemical properties of simple substances - non-metals: hydrogen, halogens, oxygen, sulfur, nitrogen, phosphorus, carbon, silicon 172
2.4. Characteristic chemical properties of oxides: basic, amphoteric, acidic 184
2.5-2.6. Characteristic chemical properties of bases, amphoteric hydroxides and acids 188
2.7. Characteristic chemical properties of salts: medium, acidic, basic, complex (using the example of aluminum and zinc compounds) 194
2.8. Interrelation of various classes of inorganic substances 197
3. Organic chemistry
3.1-3.2. Theory of the structure of organic compounds: homology and isomerism (structural and spatial). Hybridization of carbon 200 atomic orbitals
3.3. Classification of organic compounds. Nomenclature of organic compounds (trivial and international). Radical. Functional group 207
3.4. Characteristic chemical properties of hydrocarbons: alkanes, cycloalkanes, alkenes, dienes, alkynes, aromatic hydrocarbons (benzene and toluene) 214
3.5. Characteristic chemical properties of saturated monohydric and polyhydric alcohols, phenol 233
3.6. Characteristic chemical properties of aldehydes, saturated carboxylic acids, esters 241
3.7. Characteristic chemical properties of nitrogen-containing organic compounds: amines, amino acids 249
3.8. Biologically important compounds: fats, proteins, carbohydrates (mono-, di- and polysaccharides) 253
3.9. Relationship between organic compounds 261
4. Methods of knowledge in chemistry. Chemistry and life
4.1. Experimental Fundamentals of Chemistry 266
4.1.1-4.1.2. Rules for working in the laboratory. Methods for separating mixtures and purifying substances 266
4.1.3-4.1.5. Determination of the nature of the medium of aqueous solutions of substances. Indicators. Qualitative reactions to inorganic substances and ions. Identification of organic compounds 266
4.1.6. The main methods of obtaining (in the laboratory) specific substances belonging to the studied classes of inorganic compounds 278
4.1.7. The main methods of obtaining hydrocarbons (in the laboratory) 279
4.1.8. The main methods for obtaining oxygen-containing organic compounds (in the laboratory) 285
4.2. General ideas about industrial methods for obtaining essential substances 291
4.2.1. The concept of metallurgy: general methods for producing metals 291
4.2.2. General scientific principles of chemical production (using the example of the production of ammonia, sulfuric acid, methanol). Chemical pollution of the environment and its consequences 292
4.2.3. Natural sources of hydrocarbons, their processing 294
4.2.4. High molecular weight compounds. Polymerization and polycondensation reactions. Polymers. Plastics, rubbers, fibers 295
4.3. Calculations using chemical formulas and reaction equations 303
4.3.1-4.3.2. Calculations of volumetric ratios of gases and thermal effect in reactions 303
4.3.3. Calculation of the mass of a solute contained in a certain mass of a solution with a known mass fraction 307
4.3.4. Calculation of the mass of a substance or volume of gases from a known amount of a substance, mass or volume of one of the substances participating in the reaction 313
4.3.5-4.3.8. Calculations: mass (volume, amount of substance) of the reaction product, if one of the substances is given in excess (has impurities) or in the form of a solution with a certain mass fraction of the substance; practical yield of product, mass fraction (mass) of substance in mixture 315
4.3.9. Calculations to find the molecular formula of a substance 319
Typical exam paper
Instructions for performing work 324
Answers to the standard version of the examination paper 332
Answers to tasks for independent work 334
APPLICATIONS 350
This course material is intended for 11th grade students. By this time, the program of general and inorganic chemistry has been completed; students in the main course are already familiar with the types of calculation problems and their solutions. This makes it possible to consolidate the acquired knowledge; pay attention to the features of the structure and properties of organic substances, their relationships and interconversions, to the typology of calculation problems. When developing the material, most of the tasks and exercises were taken from the FIPI guidelines for preparing for the Unified State Exam. The main goal of preparing for the Unified State Exam is to master the skills of performing the most complex tasks, knowledge of redox reactions, the main classes of organic and inorganic compounds, as well as algorithms for solving the main types of calculation problems
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Preview:
Formulas organic matter. |
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Formulas | Titles |
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CH 2 =CH 2 | Ethylene, ethene |
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H 2 C=CH-CH=CH 2 | Divinyl, butadiene -1.3 |
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Isoprene rubber |
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Polychloroprene rubbers (nairit, neoprene) |
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Chloroprene |
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Ethine, acetylene |
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Allylene, propyne |
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Benzene, cyclohestriene-1,3,5 |
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Methylbenzene, C7H8 |
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| | Ethylbenzene |
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o-xylene, m-xylene, p-xylene, |
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Vinylbenzene, ethenylbenzene, phenylethylene, styrene |
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Dimethyl ether(C 2 H 6 O) (methyl ether, methoxymethane,) H 3 C-O-CH 3 |
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Diethyl ether C 2 N 5 OS 2 N 5 |
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Phenol (hydroxybenzene, obsolete. carbolic acid) C 6 H 5 OH - |
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Benzoic acid C 6 H 5 COOH |
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Benzoaldehyde(benzaldehyde) C6H5CHO |
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amino acids: NH 2 -C 2 H 5 -COOH alanine, NH 2 -CH 2 -COOH – glycine – |
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Ethers formic acid HCOOCH 3 - methyl formate
HCOOC 2 H 5 - ethyl formate
, Ethers acetic acid
Ethers butyric acid
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Organic compound class | General formula | Molar mass |
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Alkanes | C n H 2n + 2 | 14n+2 |
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Alkenes or cycloalkanes | C n H 2n | |||||||||
Alkynes, alkadienes or cycloalkenes | C n H 2n - 2 | 14n - 2 |
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Arenas (benzene and its homologues) | C n H 2n - 6 | 14n - 6 |
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Alcohols or ethers | C n H 2n + 2 O | 14n+18 |
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Aldehydes or ketones | CnH2nO | 14n+16 |
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Monocarboxylic acids or esters | C n H 2n O 2 | 14n+32 |
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Aromatic alcohols | C n H 2n - 7 OH | 14n+10 |
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Aromatic aldehydes | C n H 2n - 7 COH | 14n+22 |
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Aromatic acids | C n H 2n – 7 COOH | 14n+38 |
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Hydrolysis
Table 1. Change in the color of the indicator depending on the concentration of the hydrogen ion.
CHANGING INDICATOR COLOR | ||||
TYPE OF SALT | LITMUS | PHENOLPHTHALEIN | METHYL ORANGE | WEDNESDAY |
strong base + weak acid | blue | crimson | yellow | alkaline |
weak base + strong acid | red | does not change | red | sour |
strong base + strong acid | does not change | does not change | does not change | neutral |
Scheme 1. Hydrolysis of salts formed by weak acids and strong bases - hydrolysis at the anion. , alkaline environment pH> 7
PO 4 3- SO 3 2- CO 3 2- S 2- BO 3 3- PO 3 3- SiO 3 2- AsO 4 3- SnO 4 2- | HPO 4 2- HSO 3 - HCO 3 - HS - HBO 3 2- HPO 3 2- HSiO 3 - HAsO 4 2- HSnO 4 - |
Note: Me (active, alkali-forming) - Li, K, Na, Rb, Cs, , Ba, Sr.
Scheme 2. Hydrolysis of salts formed by strong acids and weak bases - hydrolysis by cation, acidic medium, pH
Cl - Br - I – SO 4 2- NO 3 - IO 3 – ClO 3 - ClO 4 - MnO 4 - CrO 4 2- Cr 2 O 7 2- | Cl - Br - I – SO 4 2- NO 3 - IO 3 - ClO 3 - ClO 4 - MnO 4 - CrO 4 2- Cr 2 O 7 2- |
Note: Me- Mg…….Au and NH 4 +
Scheme 3. Hydrolysis of salts formed by weak acids and weak bases, cation and anion hydrolysis is irreversible hydrolysis.
In this case, the products of hydrolysis are a weak acid and a base: KtAn + H 2 O = KtOH + HAn
Kt + + An - + H 2 O = KtOH + Han
where Kt + and An - - cation and anion of weak bases and acids, respectively.
Scheme 4.
Salts formed by strong acids and strong bases do not undergo hydrolysis. Neutral medium, pH=7
Strong and weak electrolytes
Strong | Weak |
1. All soluble salts. | 1. All sparingly soluble salts. |
2. Inorganic acids: | 2. Inorganic acids: |
3. Alkalis: | 3. Amphoteric bases: 4. Non-amphoteric hydroxides: 5. Organic acids: |
1) The hydrolysis process is reversible , does not proceed to the end, but only until the moment of EQUILIBRIUM;
2) The hydrolysis process is the reverse of the NEUTRALIZATION reaction, therefore, hydrolysis isendothermicprocess (proceeds with heat absorption).
KF + H 2 O ⇄ HF + KOH – Q
What factors enhance hydrolysis?
- Heating - with increasing temperature, the equilibrium shifts towards the ENDOTHERMIC reaction - hydrolysis increases;
- Adding water - because Since water is the starting material in the hydrolysis reaction, diluting the solution enhances hydrolysis.
How to suppress (weaken) the hydrolysis process?
It is often necessary to prevent hydrolysis. For this:
- The solution is made as concentrated as possible(reduce the amount of water);
- To shift balance to the leftadd one of the hydrolysis products– acid , if hydrolysis occurs at the cation or alkali, if hydrolysis occurs at the anion.
Hydrolysis of other compounds not related to salts.
1) Binary metal compounds: phosphides, nitrides, hydrides, carbides.
Their hydrolysis produces a metal hydroxide and a hydrogen compound of a nonmetal, and hydrogen from the hydride.
A) hydrides. CaH 2 + H 2 O = Ca(OH) 2 + H 2
B) carbides: upon hydrolysis, carbides can form methane (aluminum carbide, beryllium carbide) or acetylene (calcium carbides, alkali metals):
Al 4 C 3 + H 2 O = Al(OH) 3 + CH 4
(H + OH - )
CaC 2 + H 2 O = Ca(OH) 2 + C 2 H 2
C) other binary compounds: nitrides (ammonia is released), phosphides (phosphine is formed), silicides (silane is produced).
Ca 3 P 2 + H 2 O = PH 3 + Ca (OH) 2
2) Acid halides.
An acid halide is a compound that is formed when the OH group in an acid is replaced by a halogen.
Example: COCl2 – carbonic acid chloride (phosgene), which can be written as CO(OH) 2
During the hydrolysis of acid halides, as well as compounds of non-metals with halogens, two acids are formed.
SO 2 Cl 2 + 2H 2 O = H 2 SO 4 + 2HCl
PBr 3 + 3H 2 O = H 3 PO 3 + 3HBr
Preview:
Table of names of acids and salts
Acid formula | Acid name | Name of the corresponding salt |
HAlO2 | Meta-aluminum | Metaaluminate |
HBO 2 | Metaborn | Metaborate |
H3BO3 | Orthoboric | Orthoborate |
Hydrobromic | Bromide |
|
HCOOH | Ant | Formate |
Hydrogen cyanide | Cyanide |
|
H2CO3 | Coal | Carbonate |
H2C2O4 | Sorrel | Oxolate |
H4C2O2 | Vinegar | Acetate |
Hydrochloric | Chloride |
|
HClO | Hypochlorous | Hypochlorite |
HClO2 | Chloride | Chlorite |
HClO3 | Chlorous | Chlorate |
HClO4 | Chlorine | Perchlorate |
HCrO2 | Metachromic | Metachromite |
HCrO4 | Chrome | Chromate |
HCr 2 O 7 | Two-chrome | Dichromate |
Hydroiodide | Iodide |
|
HMnO4 | Manganese | Permanganate |
H2MnO4 | Manganese | Manganat |
H2MoO4 | Molybdenum | Molybdate |
HNO2 | Nitrogenous | Nitrite |
HNO3 | Nitrogen | Nitrate |
HPO 3 | Metaphosphoric | Metaphosphate |
HPO 4 | Orthophosphoric | Orthophosphate |
H4P2O7 | Diphosphoric (Pyrophosphoric) | Diphosphate(Pyrophosphate) |
H3PO3 | Phosphorous | Phosphite |
H3PO2 | Phosphorous | Hypophosphite |
H2S | Hydrogen sulfide | Sulfide |
H2SO3 | Sulphurous | Sulfite |
H2SO4 | Sulfuric | Sulfate |
H2S2O3 | Thiosulfur | Thiosulfate |
H2Se | Hydrogen selenide | Selenide |
H2SiO3 | Silicon | Silicate |
HVO 3 | Vanadium | Vanadat |
H2WO4 | Tungsten | Tungstate |
Preview:
TRIVIAL INVESTIGATIONS OF SOME INORGANIC SUBSTANCES
trivial names of substances | formulas |
potassium alum | KAl(SO 4 ) 2 *12H 2 O |
ammonium nitrate | NH4NO3 |
Epsom salt | MgSO 4 *7H 2 O |
Berthollet's salt | KClO3 |
borax | Na 2 B 4 O 7 *10H 2 O |
laughing gas | N2O |
slaked lime | |
hyposulfite | Na 2 S 2 O 3 *5H 2 O |
Glauber's salt | Na 2 SO 4 *10H 2 O |
alumina | Al2O3 |
double superphosphate | Ca(H2PO4) |
sodium hydroxide | NaOH |
caustic potassium | |
inkstone | FeSO 4 *7H 2 O |
magnesia | |
Indian saltpeter | KNO 3 |
inert gases | He, Ne, Ar, Kr, Xe, Rn |
potassium lye | |
potassium nitrate | KNO 3 |
soda ash | Na 2 CO 3 |
rock salt | NaCl |
caustic | NaOH |
silica | SiO2 |
copper sulfate | CuSO4 *5H2 O |
soda nitrate | NaNO3 |
quicklime | CaO |
nickel sulfate | NiSO4 *7H2 O |
baking soda | NaHCO3 |
salt | NaCl |
potash | K2 CO3 |
precipitate | CaHPO4 *2H2 O |
sulphur dioxide | SO2 |
silica gel | SiO2 * XH2 O |
corrosive sublimate | HgCl2 |
carbon monoxide | CO |
carbon dioxide | CO2 |
chromium-potassium alum | KCr(SO4 ) 2 *12H2 0 |
chrome peak | K2 Cr2 O7 |
zinc sulfate | ZnSO4 *7H2 O |
Chilean saltpeter | NaNO3 |
Preview:
Table - Reduction products during the interaction of metals with acids
Acids Metal | Li Rb K Ba Sr Ca NaMg |
In 2-3 months it is impossible to learn (repeat, improve) such a complex discipline as chemistry.
There are no changes to the 2020 Unified State Exam KIM in chemistry.
Don't put off preparing for later.
- 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. To successfully pass the Unified State Exam in chemistry, theory is most important.
- 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 solve thematic 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:
- Questions requiring a short answer (in the form of a number or a word) - tasks 1-29.
- 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!
