Junior high school review guidance

Chinese:

(1) Accumulation and application

Accumulation and application are the basis of Chinese learning. This section is based on the memorization of ancient poems and the accumulation of extracurricular famous quotes, The focus is on modifying incorrect sentences, inquiry, oral communication, and reading classics, as well as pronunciation, Chinese characters, word meanings, imitation sentences, writing a paragraph based on the given words, concise, coherent, and appropriate word selection, sentence selection, and sentence ordering. Choices, etc., related answering modes and techniques must be mastered point by point. If you modify the wrong sentences, you can form a special topic.

Reciting ancient poems has always been valued in Chinese teaching. The dictation of classical Chinese texts requires learning to focus on the key points based on understanding. Generally speaking, those that have both beautiful language and content are still used today, and those that can reveal the center of the full text. The sentence of the title is often the focus of silent writing. It is not difficult to find out if you look carefully.

(2) Modern Literature Reading Comprehension

Most of the selected texts for modern literature reading in the high school entrance examination are a narrative essay, an argumentative essay and a natural science article. Different reading methods can be used for reading materials with different themes. The language used when answering questions must be standardized, and professional terms in Chinese language should be used as much as possible. For example, when evaluating the language style of an article, there are professional terms such as fresh and natural, simple and elegant, concise and simple, etc.

1. Narrative reading

1) Examine the understanding of the words themselves and the expressive role of the words in specific contexts.

2) Examine the functions of lyrical sentences, argumentative sentences, transitional sentences, central sentences, and theme sentences.

3) From an overall perspective, examine the grasp of the clues of the article, and then clarify the ideas of the article.

4) From the analysis of characters and events, examine the understanding of the image analysis of characters and the purpose of the article.

5) Examine the understanding of the artistic characteristics of the article from the perspective of expression techniques and language.

6) Use association and imagination to test your in-depth understanding of the article and your ability to innovate.

7) In addition to the overall perception, pay attention to individual experience. It should be said that paying attention to individual experience is an emerging focus of the exam, which focuses on expressing your own unique insights.

Argumentative essay reading

1) Judge and summarize the central argument.

2) Distinguish the types of arguments, summarize the factual arguments, analyze the function of the arguments, and write additional arguments based on the arguments.

3) Identify argumentation methods and analyze their functions, describe how to demonstrate arguments, and from which aspects to demonstrate arguments.

4) Understand the role of key words in the text

5) Sort out the ideas, divide the levels, and summarize the level content in concise language.

6) Combine the selected articles with actual practice to examine your own perception ability, and explain your own opinions and opinions on the viewpoints and materials.

7) Combine the selected articles to examine the migration ability.

3. Reading of scientific and technological expository texts

In the test paper, in addition to testing the knowledge and abilities of the expository texts themselves, students should also be guided to pay attention to human beings, nature, ecological environment, scientific and technological processes and future development. Cultivate students' scientific literacy and understand the scientific spirit and scientific thinking methods embodied in the works.

1) Understand the meaning and function of important words in specific contexts. Such as scientific terms, concepts, content referred to by pronouns, the role of modifying and limiting words, etc.

2) Understand the meaning and function of important sentences in the text.

3) Examine the judgment of explanation objects and characteristics, examine explanation order, hierarchical structure, explanation methods and functions, explanation language, etc.

4) Summarize key points, extract information, define new concepts, prepare titles, etc.

5) Examine the innovation and expression of the explanatory content: express your own unique opinions on the phenomena and problems appearing in the article based on actual conditions; propose solutions to problems of human concern; address issues that arise in the ecological environment Write warning slogans, public service announcements, and make suggestions.

Examination questions mostly appear in the form of multiple choice, fill-in-the-blank, and short-answer formats.

(3) Classical Chinese Reading

1. Examine writers, works and other literary knowledge.

2. Examine the understanding of content words: ancient and modern idioms, polysemy, inflection of word categories, and pseudo-characters; understanding or usage of function words in classical Chinese.

3. Examine the pause rhythm of reciting classical Chinese sentences.

4. Examine the translation of key classical Chinese sentences.

5. Extract information and the role of key sentences in the text.

6. Grasp the thoughts and feelings of the main characters in the article, analyze the characters, summarize the central idea of ??the article, understand the main content of the article, and feel the truth that the article wants to express, etc.

(4) Composition

1. Proposition situation

1) The weight of topic composition has decreased, but it still accounts for a large proportion. Some provincial and municipal examination papers include topic composition as one of the multiple-choice essays.

2) Topic composition and material composition are combined.

3) Combine topic composition and proposition composition.

4) Combining topic composition and semi-proposition composition.

5) The proportion of propositional compositions and semi-propositional compositions has increased.

6) Material composition has appeared in some provinces and cities.

2. Theme content

1) Self and growth category

2) Morality and emotion category

3) Society and life category

4) The imagination and innovation category can recite several beautiful articles close to our lives according to each theme.

5 A few areas not only allow students to write essays, but also allow students to reflect and evaluate. For example, students are asked to summarize the main purpose of the article, find out what makes them satisfied, find out where to revise, and incorporate these into Go to the scoring of the essay. These papers focus on the writing process.

2. High School Entrance Examination Review Steps:

In order to have a learning goal from the beginning of the third grade of junior high school and lay a solid foundation for the high school entrance exam, it is necessary to understand the steps of the general review of the third grade of junior high school. Different regions have different review steps. There are generally two review methods:

The first method: the first round: review the texts on the syllabus lesson by lesson, and start reviewing in blocks in the second round.

The second method: review in blocks from the beginning.

3. Suggestions

1. No matter which review method is used, the key is to learn the text well. I hope that on the basis of comprehensive study, students will focus on the test points to learn firmly, improve their abilities, and draw inferences from one example.

2. Make time to read through the textbook. It is best to read a text three to five times. After reading, think about what is written, how to write it, what are the benefits of writing like this, and read it again when you have time. Think about the central idea, article structure, and after-school exercises. Try to memorize the passages that are required to be memorized in advance. In short, it is best to learn in advance if you can learn it yourself.

3. Do a good job of previewing before class, which will be beneficial to class learning. During class, compare the results of your preview with the content of class, and think about the reasons for any inconsistencies. Interact with teachers and classmates during class. If you have any questions, please consult teachers and classmates in a timely manner. Problems in class will be solved in class, and problems on the same day will be solved on the same day. It would be better if you go through the movie before going to bed and go back to it on the second and third days.

4. It is best to read extensively. No matter how tight the time is, you should also read the selected works of middle school students and the selection of excellent compositions for the high school entrance examination. You should have at least three books on hand. Compare them with the same topic to see their similarities, differences, and pros and cons. .

We must have a book of "Famous Quotes" in hand. The content should be close to our study and life, including famous quotes from ancient and modern times, both at home and abroad.

Even if you read it for 15 minutes every day, persistence is the key.

5. Keep practicing writing. Write at least two articles per week, possibly in journal form.

6. In terms of reading, do an appropriate amount of high school entrance examination questions or high school entrance examination simulation questions. You have to use your own brains to do it, and you have to rack your brains for questions you don't know. If you really can't do it, look at the answers again, and think about why the answers are different. Never copy. Various question types have certain solutions and methods, so do not be blind when answering reading questions.

You can also do timed reading training regularly in order to improve your reading speed and comprehension through continuous training.

Reading is absorption, writing is expression.

The language and skills learned in reading will be of great help to collaboration.

Mathematics:

(1) Candidates should be confident

Looking at the high school entrance examination questions in recent years, the main function of the high school entrance examination is to understand students’ mathematics learning process and evaluate students Basic mathematics proficiency is the main basis for high school admissions. Therefore, candidates do not need to doubt their mathematical abilities because they cannot solve some mathematical problems. As long as they work hard during the review stage, they will definitely achieve the desired results in the high school entrance examination.

Carefully study the "High School Entrance Examination Instructions"

The difficult geometry problems that have caused headaches for many candidates in the past have been greatly reduced in difficulty in the High School Entrance Examination in recent years. The syllabus deletes relevant proofs using the tangent length theorem, chord tangent angle theorem, intersecting chord theorem and cutting line theorem, and only requires candidates to be able to use these theorems to perform simple geometric calculations. Focusing on testing students' understanding of geometric facts and reasonable reasoning ability, it significantly reduces the difficulty of geometry test questions.

In terms of algebra, the relationship between the roots and coefficients of a quadratic equation has been deleted. Focus on testing students' ability to integrate the thinking methods of equations with the Pythagorean theorem, similar shapes, solving right triangles, circles, functions, etc. Understanding and seeing clearly the scope of the exam and the trend of the questions can avoid detours and wrong paths.

(2) Generally speaking, three rounds of review can be arranged

In the first round, a systematic review of basic knowledge will be carried out. The context of junior high school mathematics is connected by basic concepts and mathematical thinking methods. Each basic mathematical concept is the most basic way of thinking in mathematics. For example, in a simulation of the high school entrance examination in a certain school, there was such a multiple-choice question: "If a and b are opposite numbers to each other, then among the following pairs of numbers ( ) are not opposite numbers to each other. A. -2a and -2b B. a 1 and b 1 C.a 1 and b-1 D.2a and 2b”. The teacher was surprised to find that this was the question with the second highest score loss rate among the 10 multiple-choice questions. The reason is that the candidates' conceptual understanding of opposite numbers is still at the level of "the numbers are the same but the signs are opposite", and they fail to grasp the essence of "the sum of two numbers is zero". In fact, the examples, exercises, and exercises in the textbook provide a rich source of questions for preparing mathematics test questions for the high school entrance examination. These questions mainly test the candidates' understanding of basic concepts. The previous question reflects the examinee's disregard for basic concepts during the review process. Therefore, it is recommended that candidates should pay special attention to reviewing the basic concepts in textbooks at this stage, and focus on understanding the concepts through the analysis of concepts.

In the second round, special review of difficult knowledge will be carried out. In recent years, a large number of good questions that are active, interesting, beneficial, and enlightening have emerged in high school entrance examinations in various places. Candidates should review these hot questions carefully and make special breakthroughs under the guidance of teachers.

Note: You should have a compilation of high school entrance exam questions from various provinces and cities. You must know that the exciting question types that appear in exam questions from other places are often a reference for local propositions.

In the third round, simulation training is conducted. It is recommended that candidates, in addition to normal school simulation training, should use the high school examination papers from various places, set standard times, and conduct self-simulation tests. Note: Your own scoring should be based on the scoring standards in the reference answers, and you should not just look at the answers without looking at the points. Otherwise, it would be a pity to develop the habit of "skipping steps" in solving problems and lead to unnecessary loss of points.

(3) Cultivate a good habit of reflection after reviewing and solving problems

To effectively cultivate mathematical problem-solving abilities, we must do a good job in every aspect of problem-solving without compromise: reviewing the problem, formulating the solution Problem plan, solution expression, and reflection after solving the problem. Facing the high school entrance examination, candidates are forced to jump into the sea of ??questions, hoping to win with more, but in the end they often get twice the result with half the effort. The reason is that many candidates solve problems for the sake of solving them during the review process, and until they are satisfied with the solution or proof, they have no time to consider or have any awareness of the enlightenment that can be obtained from solving the problems, and therefore lack the awareness of themselves. Reflecting on the cognitive process of problem-solving makes it difficult to obtain more meaningful information beyond the existing information, which reduces the rate of return on problem-solving. Simply put, many candidates only do the middle two links in the problem-solving process, and do not pay much attention to the reflection after reviewing the questions and solving the problems.

For example, there is a high school examination question: "The fruit vendor bought 100 kilograms of oranges at a unit price of 2 yuan/kg. Due to transportation, storage and other reasons, 5 kilograms were lost. After sorting, the vendor prepared to divide the remaining oranges into two grades for sale, which is better The selling price is 3.2 yuan/kg, and the general selling price is 2.6 yuan/kg. (1) After all are sold out, based on the total purchase volume, what is the average profit range per kilogram? (2) If the merchant is in this business? If the total profit is expected to be no less than 80 yuan, how many kilograms of oranges should be classified as the best grade?" Many candidates only found out that the whole sentence "calculated based on the total purchase volume" was not seen when answering. This is It is caused by not developing good problem-reviewing habits when solving problems.

Question review is the basis for problem solving. It is necessary to completely clarify the meaning of the text statement and symbols of the problem, accurately grasp the conditions and conclusions of the problem, and draw appropriate diagrams when necessary to list and refine the key points of the problem. Form the context of the topic and outline the outline. Reflection in problem solving refers to learners’ in-depth reverse thinking about their own problem-solving activities. It is not just a general review or repetition of mathematical problem-solving learning, but an in-depth study of the knowledge and knowledge involved in mathematical problem-solving activities. Methods, ideas, strategies, etc., to solve a type of problem. Therefore, the Hungarian-American mathematician George Polya said: "The solution to a mathematical problem is only half, the more important thing is the review after solving the problem." It is recommended that candidates prepare a special problem-solving reflection book during the review process, excerpt some typical example questions, especially typical mistakes, and comment on each question what basic knowledge and basic knowledge they used in the process of solving the problem. Methods and mathematical thinking methods, which steps are prone to errors when solving the problem, are there other methods, what are the difficulties of the problem, how to break through, can the problem be generalized, what shortcomings do you have when solving the problem and set up for solving the problem Obstacles etc. Take this book out and review it carefully when the high school entrance examination is approaching. It will be more targeted than reading books or other materials, and the review effect will naturally be better.

English:

1. Formulate and adjust review plans

Students should reasonably formulate and adjust review plans in a timely manner, not only monthly plans, weekly plans, but also There should be a daily study plan. From the review plan for each book to the study plan for each unit and lesson, there should be good arrangements. The third grade of junior high school needs to master about 1,500 words, 200-300 phrases, and nearly 100 useful sentence patterns. Without planning, it is difficult to review thoroughly in a short period of time. At the same time, when formulating a review plan, you should fully consider the teacher's teaching progress. It is best to do it simultaneously with the teacher's review plan, or you can do it a little earlier so that your review plan is closely linked to the teacher's review guidance, which can help you improve well. Review efficiency, grasp the key points and difficulties of knowledge, and never completely deviate from the teacher's review progress.

2. Strengthen the training of basic knowledge

For the review of basic knowledge, we should adopt the method of sorting out the knowledge structure and building a knowledge framework, so that the review of basic knowledge is based on the interconnection between knowledge on the basis of.

1. Read the textbook thoroughly and grasp the key points

Review the textbook knowledge as planned every day, and memorize words, phrases, sentence patterns and key points diligently. Must memorize fixed phrases and idioms and be able to memorize them. Phrases can also be summarized and reviewed. For example, phrases related to the verb take include: take care of, take...to..., take (it) away, take turns, take an active part in, take place, etc.

2. Strengthen grammar induction and practice

Grammar knowledge is the outline of word choice and sentence making. By mastering grammar knowledge, you can correctly understand and use sentences, and through the review of sentences, you can deepen your understanding of grammar. review. Only with correct knowledge of grammar can you write grammatical expressions. In particular, the eight tenses and two voices should be combined with specific sentences and summarized and compared to achieve the effect of drawing inferences from one instance.

3. Pay attention to the use of situational communicative English and cultivate transnational cultural awareness

Under the guidance of the new curriculum, the English examination paper emphasizes highlighting the context, paying attention to communication, and embodying communicative English in the high school examination paper There are many places to test, and the test questions include: listening, multiple choice fill-in-the-blank, reading comprehension and writing. Therefore, when reviewing English, you should pay attention to the functions of language and cultivate your own transnational cultural awareness.

3. Focus on training on weak areas

By analyzing the errors in the test papers, students should promptly discover which question types they lose more points on before the high school entrance examination. You should concentrate on making up for your weaknesses. Such as strengthening the spelling of vocabulary, accumulating good sentences to prepare for writing, etc. Only in this way can you improve your performance faster. For question types that test ability, it is even more important to improve learning strategies as soon as possible and break through the limits of ability.

1. Listening training

The listening test mainly tests the candidate's ability to obtain information through hearing. Students should use their spare time to do listening training for 15 minutes every day. When training, you should focus on training your ability to predict the content of listening materials, capture key details, grasp the main content and theme ideas, and correctly identify the attitudes and feelings of characters and their relationships. At the same time, intensive listening and extensive listening should also be combined.

2. Reading ability training

The cloze and reading comprehension questions that appear in the high school entrance examination are both types of questions that test students' reading ability. When training, you should take the following steps: 1. Skim read to understand the main idea of ??the article. 2. Bring questions and don’t look for answers in the original text. 3. Carefully examine difficult questions, find the basis, and determine the correct answers. 4. Review the content of the article again to make sure nothing is missed.

3. Training in written expression

The high school entrance examination requires students to be able to use learned sentence patterns, phrases and language functions to express certain meanings or express their own opinions. During the review period, it is necessary to practice good writing methods, practice abbreviations, rewrites, look at pictures and write words, write according to Chinese prompts, etc., and constantly summarize and improve. When practicing writing, you should first analyze the subject matter and genre, understand the requirements, do not miss the key points, express it in your most confident sentences, avoid using long and complex sentences, and pay attention to adjusting the sentence structure and order. Finally, check for spelling, punctuation, tense, etc. errors.

4. Focus on training on the types of questions for the high school entrance examination

It is necessary to keep abreast of the high school entrance examination information, and to fully understand the annual high school entrance examination syllabus and question types, so as to be aware of it. In addition to the above points, it is also an important step that cannot be ignored to choose exercises that match the question types of the high school entrance examination so that you can understand the types of questions, score ratios, master the answering methods, and skillfully control the answering time.

Physics:

All calculation formulas in junior high school: /question/26852506.html

Chemistry:

1. Structure

Atomic Ion Molecule

The structure of the atom "Nucleus and electrons outside the nucleus"

Ion atoms gain or lose electrons Then it becomes an ion

A molecule made of 2 or more atoms is called a molecule

Element The type of atom contained in a substance, such as water is Water molecules are composed of oxygen and hydrogen elements. Schlein and Schwann discovered that atoms are different. The reason why atoms are different is because the number of protons is different (8 oxygen, 8 hydrogen, 1 carbon, 6 carbon). Around the number of neutrons, we also discovered that isotopes have the same protons but different numbers of seeds

Classification of substances ①Elements and compounds

Elements are an object made entirely of one element

Compounds are made up of two or more elements

②Pure substances and mixtures

Pure substances have only one molecule or only one kind Atoms are composed of molecules that do not contain other molecules.

For example, there is oxygen and nitrogen in the air. When they are mixed together, they become a mixture, but distilled water is a pure substance.

2. Chemical formula

First we need to understand the meaning of the numbers inside

H20 or C02. The 2 in the lower right corner of the letter (lowercase) means that there are two hydrogen atoms in the molecule. There are 2 oxygen atoms

2CO means there are 2 carbon monoxide. The number in front of the chemical formula indicates the number of atoms (or molecules)

CL`` represents an ion The 2- or 2 in the upper right corner of the letter indicates its charge number. 2 means the loss of 2 electrons because the electrons are negatively charged

Common metals with valence generally show positive valence

Iron Fe is positive 3 or positive 2

Al Aluminum positive 3

H Hydrogen positive 1

Manganese Mn positive 4

Oxygen O negative 2

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Copper C u positive 2

Sulfur S positive 6

Carbon C 4 or 2

Magnesium Mg 2

Potassium K plus 1

Ca Calcium plus 2

Zinc Zn plus 2

Sulfate SO4 minus 2

Cl Chlorate minus 1

Hydroxide OH minus 1

CO3 Carbonate minus 2

NO3 Nitrate minus 1

NH4 Ammonia minus 1

To write, write the positive ones at the front and the negative ones at the back, for example, H2O "H is the negative valence of the positive O"

Read from the back to the front, for example Na2SO4 "The first Na is sodium, the second one is sulfate, and it is read forward as sodium sulfate."

It is also recommended that you memorize the first 40 common substances in Mendeleev's periodic table. Don’t mistake Au (gold) for iron (Fe).

You don’t have to memorize the relative molecular mass test given by others

To judge this kind of thing Whether it exists depends on the valence

The valence is 0. This thing exists. For example, H20. Oxygen is negative 2 and hydrogen is 2*1 of positive 1 -2=0. It exists

CO2 C positive 4 O negative 2 together still exist as 0

3. Chemical equation

The formula that represents a chemical change is called chemical equation

2H2 02 combustion = 2H20 Hydrogen burns in the air and becomes H20 water

↑ The reactants are on the left

The ones on the right are the products and the ones above the equal sign are the conditions of the reaction

The way to identify chemical changes is to see whether new substances are produced

Chemical reactions in the laboratory

2KmnO4 heating = K2Mn04 Mn02 02↑ The formula for producing oxygen

2KCl03 heating = 2KCl 3O2↑ Same as above

2Na 2H20 = 2NaOH H2↑ The formula for producing hydrogen

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CaO H2O=Ca(OH)2 Quick lime water produces hydrated lime

2H202=2H20 02↑ Hydrogen peroxide produces oxygen

Ca(OH)2 CO2=CaCO3↓ H2O. Pass carbon dioxide into clear lime water and the lime water becomes turbid.

Fe H2SO4= FeSO4 H2↑ Iron reacts with dilute sulfuric acid to produce ferrous sulfate

Fe 2O3 3H2SO4= Fe2(SO4)3 3H2O The reaction between iron oxide and dilute sulfuric acid produces iron sulfate

(The 3-valent iron is called iron, the 2-valent iron is called ferrous iron, such as 2 above Bar formula)

2H2 O2=2H20 Hydrogen burns in air to produce water

2H20=2H2↑ O2↑ Electrolysis of water produces hydrogen and oxygen

Fe2O3 3CO2 =2Fe CO2 Blast furnace iron smelting is also called reduced iron oxide

CuO H2=Cu H2O reduced copper oxide in the laboratory

BaCl2 H2SO4=BaSO4↓ 2HCl generated by the reaction of barium chloride and sulfur White precipitate (BaSO4), so barium chloride can be used to test whether the substance contains sulfate

AgNO3 HCl=AgCl↓ HNO3 Silver nitrate and hydrochloric acid react to produce a white precipitate (AgCl), so silver nitrate can be used Check whether the substance contains chlorate

The above is the basic reaction

The method of making equations

① Write the reactants and Product

② Balance means that the number of atoms on the left is equal to all the atoms on the right

1. After knowing that hydrogen burns in the air to form water

2. List the formula H2 O2=H2O. It is obvious that there are 2 O's on the left but only one on the right

3. For balance, add 2 in front of H2 and add 2 in front of the H2O generated later.

It becomes 2H20=2H2 O2

4. Note that it is not over yet. If there is no gas in the reactant but there is gas behind it, add ↑

So the final formula should be 2H20=2H2↑ O2↑

IV. Reflected types

The four most basic types of compounds: decomposition, substitution, metathesis

① Examples of combining two substances and more than two substances to produce one substance are as follows

CaO H2O=Ca(OH)2

2H2 O2=2H20

② Decomposition is just the opposite of combination, which is the reaction of one substance to produce two or more substances

2KmnO4 heating=K2Mn04 Mn02 02↑

2KCl03 heating=2KCl 3O2↑

2H202=2H20 02↑

③ Replace one element with other substances Replace the elements in

Fe H2SO4= FeSO4 H2↑

④ Metathesis of two compounds to exchange components (AB CD=AC BD)

BaCl2 H2SO4=BaSO4 ↓ 2HCl

AgNO3 HCl=AgCl↓ HNO3

There are also some reactions that are not basic

The reduction reaction displaces oxygen

Oxidation Reaction to obtain oxygen

Neutralization reaction Reaction between acid and alkali

5. Calculation

① Let what you ask for be The relative molecular mass of Question: How many grams of water are produced when 4g of hydrogen burns in air?

Solution: Suppose the water that generates Xg ① requires water, so let water be For water and known hydrogen, just list water and hydrogen

4g X ④List the known hydrogen and unknown numbers

4/4g=36/X ⑤ List Equation

X=36g ⑥Find the result

Answer: Generate 36g of water ⑦ Perfect

6. Acid and alkali salts

① There must be H ions in the acid. Simply put, it is just an acid radical plus hydrogen

Sulfate radical SO4 minus 2

Cl chlorate radical Minus 1

CO3 Carbonate Minus 2

NO3 Nitrate Minus 1

Add hydrogen to become HCl H2CO3 H2SO4 HNO3 are all acids

② Alkali have OH and a metal ion is enough

The metal ions Na, AL, Aluminum, Cu and Copper are all good if they have gold letters next to them

So there is NaOH CuOH ALOH There are many, many, many, and this is why I have to memorize the first 40.

③ Salts have the characteristics of alkali and acid. They are called salts

The characteristics of alkali are the characteristics of metal ions and the characteristics of acids are acid radicals. Okay

There is CuSO4 AgCl NaCl. Think about it for yourself, maybe I can list them all?

Seven. Acid, alkali and salt reactions

Alkali can react with the following (whether it is established or not depends on whether there is gas precipitation or water formation)

① Acid HCl NaOH=H2O NaCl

② Non-metal oxides (SO2 CO2, etc.) Ca(OH)2 CO2=CaCO3 H2O

③ Salt CuSO4 2NaOH=Cu(OH)2↓ NaSO4

Acid can Reaction with the following

① Alkali NaOH H2SO4= Na2SO4 H2O

② Metal element Fe H2SO4= FeSO4 H2↑

③ Metal oxide Fe 2O3 3H2SO4= Fe2 (SO4)3 3H2O

④ Salt BaCl2 H2SO4=BaSO4↓ 2HCl

Salt can react with the following

① Alkali CuSO4 2NaOH=Cu(OH)2 ↓ NaSO4

② Acid BaCl2 H2SO4=BaSO4↓ 2HCl

③ It can also react with salts, but they can all be tolerated in water

AgNO3 NaCl=AgCl ↓ NaNO3

Summary of junior high school chemistry knowledge (memorization part)

1. Scientific name, common name and chemical formula of substances

⑴Diamond, graphite: C⑵mercury, mercury :Hg (3

) Quick lime, calcium oxide: CaO (4) Dry ice (solid carbon dioxide): CO2 (5) Hydrochloric acid, hydrochloric acid: HCl (6) Sulfurous acid: H2SO3 (7) Hydrogen sulfuric acid: H2S (8) Hydrated lime, slaked lime: Ca ( OH)2 (9) Caustic soda, caustic soda, caustic soda: NaOH (10) Soda ash: Na2CO3 Sodium carbonate crystals, soda ash crystals: Na2CO3·10H2O (11) Sodium bicarbonate, acid sodium carbonate: NaHCO3 (also called baking soda) (12) Bile vitriol, blue vitriol, copper sulfate crystal: CuSO4·5H2O (13) Verdigris, malachite: Cu2(OH)2CO3 (a substance that decomposes to form three oxides) (14) Methanol: CH3OH Toxic, blindness, death (15) Alcohol, ethanol: C2H5OH (16) Acetic acid, acetic acid (glacial acetic acid at 16.6°C) CH3COOH (CH3COO- acetate ion) has acidic properties (17) Ammonia gas: NH3 (alkaline gas) (18) Ammonia water, Ammonia monohydrate: NH3·H2O (a common base with alkaline properties and a base that does not contain metal ions) (19) Sodium nitrite: NaNO2 (industrial salt, toxic)

2. Color status of common substances

1. White solids: MgO, P2O5, CaO, NaOH, Ca(OH)2, KClO3, KCl, Na2CO3, NaCl, anhydrous CuSO4; iron, magnesium It is silvery white (mercury is silvery white liquid)

2. Black solid: graphite, carbon powder, iron powder, CuO, MnO2, Fe3O4▲KMnO4 is purple black

3. Red Solid: Cu, Fe2O3, HgO, red phosphorus ▲ Sulfur: light yellow ▲ Cu2(OH)2CO3 is green

4. Solution color: All solutions containing Cu2 are blue; all solutions containing Fe2 It is light green; solutions containing Fe3 are brown, and other solutions are generally not colorless. (Potassium permanganate solution is purple-red)

5. Precipitation (i.e., salts and alkali insoluble in water): ① Salt: white ↓: CaCO3, BaCO3 (soluble in acid) AgCl, BaSO4 (also Insoluble in dilute HNO3), etc. ②Alkali: blue ↓: Cu(OH)2 reddish brown ↓: Fe(OH)3 white ↓: other alkali.

6. (1) Gases with irritating gases: NH3, SO2, HCl (all colorless)

(2) Colorless and odorless gases: O2, H2, N2, CO2, CH4, CO (highly toxic)

▲Note: Liquids with pungent odor: hydrochloric acid, nitric acid, acetic acid. Alcohol is a liquid with special gas.

7. Toxic, gas: CO Liquid: CH3OH Solid: NaNO2 CuSO4 (can be used as a bactericide, mixed with hydrated lime to form a sky blue viscous substance - Bordeaux liquid)

3. Solubility of substances

1. Solubility of salt

Substances containing potassium, sodium, nitrate, and ammonium are all soluble in water

Among the compounds containing Cl, only AgCl is insoluble in water, and the others are soluble in water;

Among the compounds containing SO42-, only BaSO4 is insoluble in water, and the others are soluble in water.

Only K2CO3, Na2CO3, and (NH4) 2CO3 are soluble in water, and the others are insoluble in water

2. Solubility of alkali

Alkali that are soluble in water include: barium hydroxide, potassium hydroxide, calcium hydroxide, sodium hydroxide and ammonia. Other alkali are insoluble in water. Among the poorly soluble alkali, Fe(OH)3 is a reddish brown precipitate, Cu(OH)2 is a blue precipitate, and other poorly soluble alkali are white. (Including Fe(OH)2) Note: AgCl and BaSO4 in the precipitate are insoluble in dilute nitric acid.

Other precipitates are soluble in acid.

Such as: Mg(OH)2 CaCO3 BaCO3 Ag2 CO3, etc.

3. Most acids and acidic oxides are soluble in water, (acidic oxides + water → acid) most alkaline oxides are insoluble in Water can dissolve: barium oxide, potassium oxide, calcium oxide, sodium oxide (alkaline oxide + water → alkali)

IV. The best of chemistry

1. Earth’s crust The most abundant metallic element is aluminum. 2. The most abundant non-metallic element in the earth's crust is oxygen.

3. The most abundant substance in the air is nitrogen. 4. The hardest naturally occurring substance is diamond.

5. The simplest organic compound is methane. 6. The most mobile metal in the metal activity sequence is potassium.

7. The oxide with the smallest relative molecular mass is water. The simplest organic compound CH4

8. The gas with the smallest density under the same conditions is hydrogen. 9. The most conductive metal is silver.

10. The atom with the smallest relative atomic mass is hydrogen. 11. The metal with the smallest melting point is mercury.

12. The most abundant element in the human body is oxygen. 13. The element that makes up the most types of compounds is carbon.

14. The most widely used metal in daily life is iron. 15. China was the first to use natural gas; China's largest coal base is in Shanxi Province; China was the first to use hydrometallurgy to smelt copper (discovered in the Western Han Dynasty [Liu An's "Huainan Wanbi Shu" "Zeng Qing gets iron and turns it into copper"] , applied in the Song Dynasty); the first person to discover electrons was Thomson of England; the first person to conclude that air is composed of N2 and O2 was Lavoisier of France.

5. The "three" in junior high school chemistry

1. The three types of particles that make up matter are molecules, atoms, and ions.

2. There are three commonly used reducing agents for reducing copper oxide: hydrogen, carbon monoxide, and carbon.

3. Hydrogen has three major advantages as a fuel: it is rich in resources, has high calorific value, and the product after combustion is water and does not pollute the environment. 4. There are generally three types of particles that make up atoms: protons, neutrons, and electrons. 5. There are only three types of ferrous metals: iron, manganese, and chromium. 6. The elements that constitute matter can be divided into three categories: (1) metallic elements, (2) non-metallic elements, and (3) rare gas elements. 7. There are three types of iron oxides, and their chemical formulas are (1) FeO, (2) Fe2O3, and (3) Fe3O4.

8. There are three characteristics of solutions