The chemistry competition started on the 22nd, and I didn t review it, so everyone gave me some advi

The chemistry competition is a pure university content, and it is completely useless to do the college entrance examination paper, you can get a self-recruitment quota at most if you win the second prize, and you want to specialize in mathematics a little more.

Do the college entrance examination papers, especially in Zhejiang Province, Jiangsu, Beijing, and Shanghai.

Start by writing the reaction:

a) Cu + H2SO4 = (heating) = CuSO4 + H2 (Cu complete reaction).

n 10/64 10/64 10/64

m 10（g）

Iron replaces copper, the mass remains unchanged, indicating that iron reacts before sulfuric acid, let m=a+b, a is the mass that completely reacts with sulfuric acid, and b is the mass of copper replacement.

b) Fe + H2SO4 = FeSO4 + H2 (H2SO4 complete reaction).

n a/56 a/56

m a（g）

Replacement of iron and copper:

c) Fe + CuSO4 = FeSO4 + Cu (Fe complete reaction).

n b/56 b/56

m b（g） b/56*64=m-b（g）

Now I think you should review it like this:

1. Resolutely insist on endorsing books every morning, and the content of times is textbooks and notebooks;

2. Preview every day, don't be greedy, do the questions immediately after the preview to consolidate! Take notes and organize them;

3. Don't be stuck in difficult questions and can't extricate yourself, which will only backfire, but you must do two difficult test papers a week, and take good notes;

4. Read books and read notes every day (you can solve it when you endorse books in the morning), and the time for previewing, doing questions, and sorting notes every day shall not be less than two hours and not more than four hours;

5. Memorize the periodic table (you can memorize it in a week), and the review materials in your hand should not exceed three, I added that the school set the materials to be four, but I only used two, and the school only took it out to deal with the teacher during class;

6. Don't lose other courses;

Chemistry Competition. The "National High School Students' Chemistry Competition" of the Chinese Chemical Society is to popularize chemistry knowledge, encourage young people to get in touch with the frontier of chemistry development, understand the significance of chemistry to science and technology, social economy and people's lives, and learn the ideological methods and working methods of chemists, so as to stimulate their interest and creative spirit in learning chemistry. explore ideas, methods and ways to discover and cultivate outstanding talents at an early stage; Promote the exchange of new ideas and methods of chemistry teaching, promote the reform of chemistry teaching in universities and middle schools, and improve the level of chemistry teaching in China; Candidates are selected to participate in the annual International Chemistry Competition. The National High School Students' Chemistry Competition and Winter Camp is the highest level of chemistry competition for high school students in China, which is in line with the International Chemistry Olympiad and is the "National Games" of chemistry for Chinese high school students

Objective (1) To popularize the knowledge of chemistry, to encourage young people to get in touch with the frontier of chemistry development, to understand the significance of chemistry to science and technology, social economy and people's lives, and to learn the thinking and working methods of chemists, so as to stimulate their interest and creative spirit in learning chemistry;

2) Explore the ideas, methods and ways to discover and cultivate outstanding talents at an early stage;

3) Promote the exchange of new ideas and methods of chemistry teaching, promote the reform of chemistry teaching in universities and middle schools, and improve the level of chemistry teaching in China;

4) Selection of contestants to participate in the annual international chemistry competition. All activities and publicity related to the Contest shall be consistent with the purpose of the Contest.

I am also studying chemistry, I have been studying for 2 years, and I have competed twice, 1 bronze medal and 1 silver medal. Don't be nervous in the finals and think hard.

You're strong enough....I've only been studying for a year and I'm only 73, and now I'm in the provincial team, and our provincial team doesn't take classes, so I guess you're the same, so you have to learn by yourself, and then you can do the questions during the training camp.

But you should be fine with this strong look at the outline.

Knowledge can be made up, but ability cannot be changed, there are such good conditions, you must cherish it, make a result, I hope you can get the gold medal when you are at Xiamen University.

One. d It is obtained according to the fact that the solution is electrically neutral and the number of positive and negative charges is equal.

Two. a Hydrogen content is the nitrogen content, the ratio is calculated by using the (content atomic weight) result, which is the simplest ratio of each atomic number, the simplest formula of the compound can be found, and then the chemical formula is determined according to the appropriate amount, and the result is calculated.

Three. c At the temperature of t, in the saturated solution of m, the mass ratio of salt m to water is constant, that is, s 100 that is, the following a n (let the water be n grams) can be obtained from s 100 = a n n n n , and m ·7h2o with x is added, which is equivalent to adding salt m: x*126 (126+18*7) water becomes:

n+x*18*7/(126+18*7)

The result of the comparison between the two is still a n. Representing x as a function of a and s is the result of the requirement.

Four. caso4·2h2o caso4·1/2 h2o+3/2 h2o=caso4·2h2o

The answer is not calculated, refer to others)

One: dIt is considered to be equal in the number of positive and negative charges.