First, the scope and requirements of the assessment
The scope and requirements of the national comprehensive chemistry assessment in 2021 remain unchanged from 2020, maintaining the stability of the national volume. In the preparation for the review, you should pay more attention to the changes in the instructions of the exam in previous years. The main combing is as follows:
(1) Strengthen the "understanding of chemical symbols corresponding to physical quantities". Specific physical quantities in the high exam paper will be replaced by specific chemical symbols, and may not be indicated, such as the meaning of K(HF), KW, c(H), n(H), etc.; instantaneous rate expressions and rate constants; the correlation between activation energy and endothermic reactions, exothermic reactions and chemical reaction rates; and pressure balance constant expressions.
(2) The examination requirements for ionization equilibrium have increased. More attention is paid to the analysis of acid-base mixed logarithmic curve coordinate plot, especially the bi-coordinate plot and hyperbolic chart, combined with the comparison of acid root ion ionization constant and hydrolysis constant to determine its acidity and alkalinity.
(3) Strengthen the examination of knowledge transfer ability and information analysis ability. Migration ability is tested for hydrolytic equilibrium constants using knowledge of chemical equilibrium constants. The examination of information analysis ability such as pressure balance constant calculation, unit cell parameters, atomic coordinate parameters, effective chlorine content, chemical reaction rate constant, electrochemical co-conversion principle, material conversion mechanism, etc.
(3) Strengthen the examination of chemical experimental analysis ability, experimental expression ability, and experimental quantitative analysis ability. It is required to be able to design a reasonable experimental scheme, control the experimental conditions, preliminarily explore the experimental principle, and express the experimental phenomenon.
2. College entrance examination report
1. 2021 Question Type Prediction Table
| Chances of investigation | Frequency of investigation | The type of question | The name of the question type |
| 100% | Required question types | Multiple choice questions | Required organic, elemental periodic law inference, chemical experiments |
| Non-multiple-choice questions | Synthesis of chemical experiments and synthesis of reaction principles | ||
| 70% | Frequent test question types | Multiple choice questions | Chemistry and Life [18(II.,III.)19(I.,II.,III.)20(I.,II.,III.)] Electrochemistry [18(I.,II.,III.)19(I.,III.)20(I.,II.,III.)] Electrolyte solution [18(III.)19(I.,II.,III.)20(I.,II.)] NA Question [18 (I., II., III.) 19 (II., III.) 20 (III.)] Analysis of the course of change [18(II.)19(I., III.)20(I., II.)] |
| Non-multiple-choice questions | Large process questions [18(II.)19(I.,III.)20(I.,III.)] | ||
| 30% | Frequently asked question types | Multiple choice questions | Elemental Compounds [18(I.)] Analysis of Positive or False Ions of Ions or Chemical Equations [19(II.)20(III.)] |
| Non-multiple-choice questions | Elemental compound properties binding small process [18 (I., III.) 19 (II.)] Principle of binding of elemental compound properties [20(II.)] | ||
| 5% | Cold exam question types | Multiple choice questions | Chemical terms, material conversion, chemical equilibrium, redox reactions, Geiss's law, etc |
| Non-multiple-choice questions | Block diagram transformation, ion inference, etc |
Remarks: The above "2021 Question Type Prediction Table" is from the Leaked Tianji Chemical "Tianji Secret Book" of the Class of 2021.
2. 2021 Core Test Center Test Direction Prediction
The amount of substance
| Test to predict | Chances of investigation |
| Simple conversion of the quantity and mass, volume, number of particles, and concentration of a substance | 90% |
| Titration calculations | 50% |
| Non-titration electron conservation calculations | 20% |
| Yield calculation | 20% |
Ion reaction
| Test to predict | Chances of investigation |
| Ion reaction equations are written | 100% |
| Ion reaction equation leveling and calculation | 30% |
| Ion reaction process or action analysis | 30% |
| Ion testing or desplution | 60% |
| Chemical reaction equation writing | 50% |
Redox reaction
| Test to predict | Examination odds |
| Redox reaction leveling, writing | 90% |
| Redox reaction related calculations | 30% |
| Redox reaction process or action analysis | 50% |
| Laws and related concepts | 30% |
The structure of matter and the periodicity of elements
| Test to predict | Examination odds |
| Properties of the substance (melting, boiling point, acidity and alkalinity) | 100% |
| Particle radius comparison | 10% |
| Metallicity, non-metallicity gradient law | 15% |
| Substance category or chemical bond | 10% |
| State of matter | 20% |
| Valence or electronic | 10% |
| Particle structure | 20% |
Chemical experiments
| Test to predict | Examination odds |
| Equation writing | 90% |
| Purpose of the operation | 50% |
| Cause analysis | 60% |
| Experimental phenomenon | 60% |
| Correlation calculations | 50% |
| Experimental instruments and functions | 60% |
| Experimental operation | 50% |
| Reagents and their effects | 40% |
| Device selection and connection | 20% |
| Product inspection | 10% |
| Conclusion of the experiment | 10% |
Reactions and energy
| Test to predict | Examination odds |
| Use Geiss's law to find the reaction velocity | 80% |
| Write thermochemical equations | 30% |
| Energy size comparison | 20% |
| activation energy | 20% |
Chemical equilibrium and rate of chemical reactions
| Test to predict | Examination odds |
| Balance mobile analytics and applications | 100% |
| Equilibrium constant calculation and application | 100% |
| Rate calculation or comparison | 40% |
| Rate influencing factors | 50% |
| Conversion rate calculation and comparison | 10% |
| Equilibrium state judgment | 5% |
| Pressure calculation | 10% |
| Mechanism analysis | 5% |
Electrolyte solution
| Test to predict | Examination odds |
| Solubility product calculation and application | 40% |
| Titration phenomena, operations, or errors | 10% |
| Precipitation transformation reaction | 30% |
| Equilibrium movement analysis (ionization, hydrolysis, sedimentation equilibrium) | 60% |
| Ion concentration relationship (size or equation relationship) | 50% |
| Calculation and comparison of ionization constants | 30% |
| Curve analysis | 60% |
electrochemistry
| Test to predict | Examination odds |
| Electrode reaction writing or judgment | 90% |
| Electrode analysis, electrode reactants (production) judgment | 60% |
| Ion-oriented movement | 20% |
| Electronic movement or transfer calculations | 60% |
| Electrolyte solution selection or concentration variation | 5% |
| Total reaction writing or judgment | 10% |
| Metal protection | 10% |
Remarks: The above-mentioned "core test points of the college entrance examination" are from the 2021 leaked Tianji Chemical "Heavenly Secret Book".
3. Efficient test preparation strategies
(1) Integrated knowledge network: 1. Concatenated into a knowledge network diagram. That is, according to the idea of material transformation, sodium, magnesium, aluminum, iron, copper, carbon, silicon, chlorine, sulfur, nitrogen and their compounds are combined into a knowledge network diagram; Tandem mind network diagram. According to the idea of orderly transformation, the orderly reduction, ordered oxidation, orderly discharge, orderly neutralization, orderly calming, orderly writing, and isomers are connected into an ordered thought network diagram; according to the conservation thought, the atomic conservation, proton conservation, electron conservation, charge conservation, material conservation, mass conservation, and energy conservation are connected into a conservation thought network diagram; according to the concept of change and balance thought, the chemical balance, ionization balance, hydrolysis balance, precipitation dissolution balance are connected into a balanced thought network diagram; according to constant thought, The chemical equilibrium constant, the ionization equilibrium constant, the hydrolytic equilibrium constant, the solubility product constant, the Avogadro constant, and the rate constant are connected in series to form a constant thought network diagram.
(2) Question type adaptation training: For the chemical non-multiple choice questions, the process flow question type, the principle comprehensive question type, and the experimental comprehensive question type, the centralized training is in the form of question type adaptation to train students' "one question and multiple changes" strain thinking. For example, the college entrance examination variant paper, each college entrance examination real question according to the same material isomer and isomorphic heterogeneous two forms of variant training, students through training can quickly find out the change points of the test questions, flexible response, smooth solution, so that similar questions are not confused, training students' keen observation ability, broaden thinking.