Learn high school chemistry, high school chemistry learning website

Let's do more questions, and there are notes, and I have to do it in the book, and the exercises taught by the teacher have to be memorized, I'm stupid, don't they all say that a good memory is not as good as a bad pen, I don't have a total score of 100 in high school chemistry, but I don't look for questions to do, just do the teacher's assignment, never copy Our school is just a general high-quality high school, and if you do more, you will master the rules of solving many problems, and then there will be a lot of shortcuts and tricks Chemistry is a very ok subject I like it very much, I hope you will improve in the future Come on.

The periodic table is a useful tool.

For example, my table mates didn't do very well in chemistry.

Later, due to interest memorized the periodic table of chemical elements.

The first exam after that.

The score is 96, and there are a lot of knowledge points in chemistry, and it is also very miscellaneous.

But the most important, and most basic, is the periodic table of chemical elements.

Common phenomena can be understood in terms of the periodic law of chemical elements.

The so-called reading the book is small.

In fact, the study of chemistry itself is a concrete interpretation of the periodic table of chemical elements, and it is a bridge between chemical elements.

To use an analogy:

The relationship between the English alphabet and the English language.

If you are in a key high school, you have to make up the textbook first, don't think that the textbook is so knowledge, you can memorize it, in fact, there is still a bit of literature in chemistry, because it has to memorize a lot of things, you have to read the textbook a lot, and find problems from it.

Don't have too many exercises, but be precise, you can do a few types of questions, think more, experience more, and after a long time, you will fall in love with the science of chemistry.

I'm understandably from the past.

Chemistry is different from other disciplines, like mathematics, if you don't have the ability to learn this aspect, you can't learn it well, but chemistry is much better, no matter what it takes, most of it is something that needs to be memorized, and then you need to think a certain amount on this basis, this knowledge can be made if you know it, and if you don't know it, you won't know anything. So be familiar with the knowledge in the textbook, especially the chemical equations. I don't know if you have noticed, especially for chemical inference, that relies on the accumulation of your chemical equations.

In fact, chemistry is very simple, as long as you remember those common chemical valences!

It's easy to remember the common oxidation laws.

There are also color variations such as common metals, remember!

Do more questions and summarize more.

Be interested in learning.

I'm also from here.

The key and difficult points should be remembered. Connect more with the knowledge in the textbook.

Believe that you can learn well.

What needs to be memorized, be sure to memorize; You don't have to do a lot of questions, but keep in mind that you will draw inferences.

Diligence can make up for clumsiness, do type questions, and draw inferences from one another.

There shouldn't be too many exercises, but you should be precise, and you can do a few types of questions.

Search the Internet and there are a lot of them.

I am a chemistry student in Shanghai, and I just finished the college entrance examination this year, which is my profound experience, and I hope it will help you

Learning Method: Return to textbooks, notes, homework.

If you have notes to copy notes, you have no notes to copy the key points and example questions on the book, you have to take your brain to copy, and the content must be copied to a complete understanding before copying, copying once is equal to learning again. At present, Shanghai's exams (especially the college entrance examination) are a return to textbooks, and any question has a basis to follow, and this "evidence" is the textbook.

When you get familiar with the concept, you have to read the homework assigned by the teacher, understand it all, ask questions if you don't understand, and at least you can understand the solution to the problem.

When I first entered the third year of high school, I only got 80+ in the 150 paper of the chemistry exam, and this method made my score go up to more than 120.

Precipitate first, and the excess precipitation disappears to form silver ammonia solution ([Ag(NH3)2]0H)AGNo3+3NH3·H2O [AG(NH3)2]OH+NH4NO3+2H2O

Adding aldehydes to tung touch to do heating is a silver mirror reaction.

ch3cho+2[ag(nh3)2]oh→ch3coonh4+2ag↓+3nh3+h2o

I wish the landlord a good time to learn and make progress

First of all, you have to understand what is going on, it is the reaction of aluminum hydroxide and sodium hydroxide to dissolve, because the volume of sodium hydroxide solution consumed is 10ml, so the consumption of oh-=, according to the equation can be calculated the amount of al substance is.

a.If the magnesium and aluminum alloys are all aluminum (assuming), then at least the aluminum hydroxide precipitate should be consumed), that is, 30 ml of NaOH solution, so the maximum value of a is 80-30 = 50 (no equal sign, because there is still mg), if the acid is completely reacted with the metal, then a = 0

b.It's easy to make an ab. Because n(al)=, n(oh-)=, which reacts with aluminum, and because the precipitation is generated, n(mg)=(you can understand it if you think about it, don't say much), so n(mg) n(al)=(because n(al=, so n(mg) n(al)=(,a's minimum is 0, so n(mg) n(al) the maximum value is.

c.From Figure 2, we can see that 2n(mg)+3n(al) = the amount of substances that generate hydroxide precipitates), and then from the inflection point, we can see that n(al)=, and the two equations can be combined to eliminate n(al) to obtain n(mg) = (, and then the range of a can be found according to the value of mg. The value of mg is 0dImitation c gives two equations 2n(mg)+3n(al)=

n(al)=

Similarly, by subtracting n(al) to obtain n(mg) = (, the range of mg's values is .

0 The answer comes out.

You have to give how much magnesium-aluminum alloy there is or how much HCl solution there is, otherwise the question cannot be answered!

A planar molecule with a high degree of symmetry means that it has multiple axes of symmetry (highly symmetrical) and all the atoms in the molecule are in the same plane (planar molecule).

A option is not actually able to distinguish between benzene and other olefins. For example, ethylene CH2=CH2 has two axes of symmetry, which can also be said to be "highly symmetrical". However, it is also an olefin.

If benzene really wants to reflect the difference between it and other olefins, then it must reflect the special properties of its benzene ring - the large bond makes its bond different from the general carbon-carbon double bond. A high degree of symmetry is only a geometric feature, which generally does not reflect the molecular characteristics well. For example, C60 (football ene) is also highly symmetrical, but this has little to do with how its molecules are composed.

Highly symmetrical, ethylene can.

So this does not reflect that benzene is different from olefins.