How to get a high score on the chemistry test?

In the process of learning chemistry, there are many problem-solving methods and skills, as long as we pay more attention and practice more. Mastering the methods and skills of solving problems will not only make the learning of chemistry easier and save us a lot of time, but also allow you to get unexpected fun from it. Let the chemistry teacher of Zhixue come to the learning and explanation of chemistry problem-solving methods and skills with the students.

1. Extreme hypothetical method:

Example: After mixing potassium chlorate with manganese dioxide, put it into a test tube and heat it, after full reaction, the mass of the remaining solid in the test tube is about ( ) a, b, c, d, Hint: The mass of the remaining solid in the tube is the total mass minus the mass of potassium chlorate to release oxygen.

There is no need to rush to calculate this problem, it is easy to see that the mass of the remaining solid is between and , so a and d are discharged, and the remaining b and c are then selected: 2kclo3 - 3O2

m m=96 It is clear that m< =

The mass of the remaining solid must be greater than ".

2. Balance balance problems:

Example: 98g of dilute sulfuric acid with a solute fraction of 10% at each end of the balance, which group of metals ( ) A, 1gmg, 1gzn B, 3gmg, 3gzn c, 5gmg, 5gzn d, 7gmg, 7gzn should be added to the solution at both ends to keep the balance in balance.

Choice for this question: D.

3. Equivalent substitution method.

Example: Add an appropriate amount of dilute sulfuric acid to the barium chloride solution, and after the reaction is complete, weigh the mass of the solution and the mass of the original barium chloride solution equal, and find the mass fraction of dilute sulfuric acid. Analysis:

Before and after the reaction, the mass of the solution is equal, indicating that the mass of the precipitate produced is equal to the mass of the dilute sulfuric acid added. That is, the mass of sulfuric acid is divided by the mass of barium sulfate.

4. Conservation Law:

Example: There is a chemical reaction 3A+B+2C=D, 15 grams of A, B, and C are mixed evenly and heated to generate 30 grams of D. After adding 10 ga to the residue, the reaction resumes again, and when the reaction stops again, only C remains in the reactant.

The following statements are true ( ) A has 9 g B left when the first reaction stops, C has 6GC left when the first reaction stops, the mass ratio of A and C in the reaction is 5:3 d, and C has 5 g left after the second reaction. Analysis:

A comprehensive analysis of the two reactions showed that 25 g a and 15 g b were exactly completely reactive. When the first reaction is stopped, 15 g A (fully reacted) consumes 9 g of B and consumes 6 g of C. When the first reaction stops, B has 6 g remaining, and C has 9 g remaining.

The mass ratio of A to C in the reaction is 15:6=5:2.

Let the mass of the reaction consume c be xg, then there is 25:x=5:2, x=10g.

Do the questions carefully, and you must get the points you will do

The maximum score in chemistry in the college entrance examination is 100 points. The "3+x" scheme used by some provinces (municipalities and autonomous regions) in China refers to "Chinese, mathematics, and foreign languages", and "x" refers to the fact that students can independently choose one of the two comprehensive subjects of liberal arts (covering politics, history, and geography) and Gao Yuqian science comprehensive (covering physics, chemistry, and biology) according to their own wishes. The difference between the total scores of the college entrance examination in various provinces and cities across the country:

The total score of most provincial college entrance examinations is 100 points.

Chemistry: Chemistry is a kind of natural science, mainly at the molecular and atomic levels, to study the composition, properties, structure and change laws of matter, and to create new substances (essentially molecules that do not exist in nature). The world is made up of matter, and there are two main forms of change: chemical and physical changes (and nuclear reactions).

Different from particle physics and nuclear physics, which study smaller scales, chemistry studies the material structure of atoms, molecules, ions (clusters), chemical bonds, intermolecular forces, and other interactions.

There is no specific score requirement; Based on the score of the paper, A, B, C, etc. are delineated according to the cumulative proportion of the closest % of the actual number of examiners.

Taking Zhejiang Province as an example, the high school examination results adopt a grading system, with five grades: A, B, C, D, and E, and E is unqualified. Based on the paper score, A, B, C, etc. are delineated according to the cumulative proportion of the closest % of the actual number of examiners, and the proportion of E is not more than 5%. The grades of students in the internal senior class and the internal vocational class that have been approved are separately delineated.

Implement a system of individual performance diagnosis and report. The grade level and the individual score diagnosis report can be queried by the Zhejiang Provincial Education Examination Institute**, and the grade level will be provided to the candidate's school. Ordinary high school students who are transferred from other provinces, return to school after going abroad for study and exchange, enlist in the army, or are admitted to the university in advance, and who do not take the examination subjects and need to be recognized for their grades, shall be implemented in accordance with the relevant documents of the department.

The current academic examination system has a full score of 70 points, so it is 42 points to pass. However, there is no such thing as a passing grade in the strict sense, because the grades are divided according to the proportion of the number of people. Maybe you scored below 42 but still passed the exam.

All students who rank in the bottom 5% of the number of people who take the exam will be judged as failing and will be required to take the subject again next time. In both cases, there will be one chance to retake the exam, and the fee for each exam is 20 yuan.

Chemistry is generally a perfect score of 100 and a passing grade of 60.

If you want to get a high score, then you have to study hard, so these are all issues that need to be paid attention to. And you must find a learning method that is suitable for Zen Hongxian, and at this time, you must recite some chemical congratulatory beats, and you must have a good foundation, so that you can get high scores.

1. How should I study to get a high score?

Many people may think that chemistry is very difficult, and they didn't study chemistry at that time, because they felt that they couldn't learn it, so they chose to study liberal arts at that time. But you must find a learning method that suits you, and I think that chemistry is also very interesting. Everyone must memorize chemical formulas, and they must memorize some knowledge points in daily life, because these knowledge points must be memorized, and they will be tested in every exam, so everyone must lay a good foundation for themselves.

2. What issues do we need to pay attention to?

And we must have a good learning mentality, there are some people who are usually very nervous in life, because these students are too concerned about their grades, so they can't play normally during the exam, so their grades will be very poor. Therefore, you must find a method that suits you, and you must have a good attitude in life, and you don't need to be so nervous when you take the exam, as long as you study hard in life, then you can get good results.

III. Conclusion. If you want to get a high score, then you have to study some difficult questions, and you must pay attention to checking your test papers when you take the exam. When you take the exam, you must pay attention to the time to solve the questions, and you must control your speed in life.

If you want to improve your chemistry scores, you can also seek help from your teachers.

The first is to be interested in the chemistry of Bei Xian, and then memorize more chemical equations, so that the imitation may get a high score, and the other is that when learning chemistry, the party also needs to master the introductory skills and master a learning method suitable for themselves. In addition, you need to brush up on the questions more, so that you will improve your score.

When studying, you must pay attention to memorization, you must master the learning methods and skills, memorize the periodic table of chemical elements, and memorize chemical equations well.

You should listen carefully during class, and if you encounter any questions you don't understand, you should ask the teacher immediately, and you can also make up lessons on weekdays and weekends.

First of all, you must listen carefully in class, it is best to take notes, and secondly, ask the teacher for advice.

1. Chemistry requires many aspects of ability: memory of fragmented knowledge, number crunching, descriptiveness, inference and analysis from known information, etc. However, the ability requirements in these aspects are not high, in terms of the richness and fragmentation of knowledge content, chemistry is far inferior to biology, and in terms of the amount of calculation and the difficulty of analysis, chemistry is also lower than physics and mathematics.

2. Therefore, as long as your ability is relatively balanced, chemistry questions will not become the biggest obstacle. On the contrary, if you are very poor at one area, chemistry questions that test that area will give you a headache.

3. Learning chemistry is really changing your knowledge system, and the changes in it want to change from two-dimensional to three-dimensional, and then you can suddenly look at everything you have learned from a higher perspective.

4. For example, the concept of acid and alkali, for example, metathesis reaction: when I was in junior high school, the teacher told you that the metathesis reaction generates insoluble matter, water, and gas, and the teacher told you that it is actually generated by non-electrolytes.

5. In the study of chemistry, the first method is to accurately grasp each concept, summarize some counterexamples that are often encountered, and combine the two with each other. For example, if there is a non-metal formation, it must be a covalent compound, then it will be found that ammonium chloride is an ionic compound composed of non-metals.

In this way, the concept of covalent compounds can be fully grasped. The second point of the question, you can write the steps you do next to the test question, whether it is chemistry or mathematics, physics, so that you can really know the reason for your mistakes when correcting, and at the same time, you can also talk about correcting some of your bad habits and improve your scoring efficiency.

There are currently four schemes for the college entrance examination in China, and the scoring method of each method is different.

1. The "3+X" scheme is applied to most provinces and cities.

"3" refers to "Chinese, Mathematics, and Foreign Language", and "X" refers to the student's own choice of one of the two comprehensive subjects of liberal arts (covering politics, history, and geography) and science (covering physics, chemistry, and biology) according to their own wishes. This scheme is currently the most widely used, the most mature and the most accepted in the country. The total score is 750 points (150 points in Chinese, 150 points in mathematics, 150 points in foreign language, 300 points in comprehensive liberal arts and comprehensive science).

2. "3 + Academic Level Test + Comprehensive Quality Evaluation" program, application area: Jiangsu.

With the approval of the Ministry of Education, since 2008, Jiangsu Province has implemented the college entrance examination program of "3+ academic level test + comprehensive quality evaluation". Among them, "3" refers to "Chinese, Mathematics, Foreign Language", with 160 points in Chinese (40 points in liberal arts plus test questions), 160 points in mathematics (40 points in science plus test questions), and 120 points in foreign language, with a full score of 480 points.

The compulsory subjects of the Academic Proficiency Test include 7 subjects: Physics, Chemistry, Biology, Politics, History, Geography, and Information Technology, with an original full score of 100 points for each subject, and candidates are required to take 5 compulsory subjects that are not selected as elective subjects for the Academic Proficiency Test. The elective subjects of the academic proficiency test include 6 subjects: physics, chemistry, biology, politics, history, and geofluid, and the original full score of each subject is 120 points.

Liberal arts candidates must take history, science candidates must take physics, and then choose one subject from chemistry, biology, politics, geography, and general candidates must all achieve a C before they can take the college entrance examination and elective subject tests. The academic proficiency test is graded and divided into 4 categories: A, B, C, and D.

3. Shanghai plan.

Compulsory subjects: Chinese, Mathematics and English, each subject has 150 points, of which English is tested twice a year, and the highest score is taken.

Physics, Chemistry, Biology, Politics, History, and Geography choose 3 subjects, 70 points in each subject, according to AA+??Proportional points are given. Among them, the geography grade is tested in the second year of high school. The total score is 660 points.

4. Zhejiang plan.

Compulsory subjects: 150 points in Chinese, 150 points in mathematics, 150 points in foreign language.

Elective subjects: Politics, History, Geography, Physics, Chemistry, Macro-Ambush, Biology, Technology, students should choose 3 subjects as the optional subjects for the college entrance examination.

Examinations for elective subjects will be held twice a year, in April and October. A total of 3 unified examinations are arranged for each subject, candidates can decide their own time to participate, each subject can take up to 2 times, and the results of the selected subjects will be assigned grades, such as the top 1% of the score will be assigned 100 points to join the total score of the college entrance examination. The total score is 750 points.