How does chemistry improve in 9 days? For practical advice, let s talk about it briefly.

1, first of all, you have to love it, you are not interested, how can you improve it if you look at it disgusting? In fact, you don't have to be exam-oriented education to produce talents!

2. Be imaginative. What's the best way to learn English? It's throwing you into an English-only environment.

The same is true of chemistry, every plant and tree around you, the flow of air, and even your own breathing are chemical reactions, and when you look at the world with the idea that everything is chemical, you will find that the whole earth, the chemical composition of the entire universe, as small as a stone being processed into lime, the evolution of the burning of a piece of paper.

3. Do the questions. When I was in school to study chemistry, I loved to do questions, because chemistry has a lot of similar questions, unlike mathematics and physics, you can change numbers like mathematics, chemical changes have their own specific laws, especially when I was in school, there are not many types of chemistry that I came into contact with, you can be divided into many common types in life, such as iron, aluminum, magnesium, calcium, one by one, do more questions, you can remember the answers, don't have to think, write the answers directly. Do 10,000 questions in mathematics to increase one point, and do 10,000 problems in chemistry It is estimated that you will get a full score!

Let's start with the basics, find a good information, and go through the knowledge, which will improve greatly. It's not bad to get a tutor either.

Read the book, be able to memorize the general outline, and then find a reference book to read the summary of each chapter of it, and try to memorize it

Memorize formulas to sort out the context of knowledge, and be clear about the content of the whole study, that is, to see the questions and know what knowledge points it is testing.

It's a junior high school student! Read more books in the last few days. Focus on the textbook, pay attention to some small details in the textbook, such as test steps, precautions, etc., and read them carefully.

There is only one book, all the chemical formulas must be memorized (including trim, of course), not to be rushed, and the mentality is also one thing!

Add saturated saline to the Erlenmeyer flask to moisten the wire, insert a single-hole plug with a catheter, and after the other end of the catheter is raised into the red water for 2-3 minutes, the liquid level of the red liquid in the catheter is observed to rise (raised, lowered, unchanged, uncertain).

Because of the galvanic corrosion that occurs inside the Erlenmeyer flask.

Negative electrode: Fe - 2E- +2OH - == Fe(OH)2 Positive electrode: O2 + 4E- +2H2O == 4OH - The oxygen in the air is consumed, so the air pressure in the Erlenmeyer flask drops, the liquid is pressed into the catheter by the outside atmospheric pressure, and the water level in the catheter rises.

Are car emissions a cause of climate warming? Or air pollution?

Exhaust emissions from automobiles are not considered to be the cause of climate warming, but air pollution.

The exhaust gases emitted by automobiles are mainly nitrogen oxides and carbon monoxide, which pollute the atmosphere, but are not the cause of climate warming (the cause of climate warming is mainly carbon dioxide).

Air pollution corresponds to exhaust gases emitted by automobiles.

Climate warming corresponds to the burning of coal and oil.

1,cDecomposition reaction refers to the reaction of one substance to produce multiple substances2,bOxygen and inert gases do not react.

3, a is used when preparing solutions.

Potassium permanganate is used to prepare oxygen, which requires an alcohol lamp to heat, an iron stand, and BCD

The answer upstairs was wrong for three reasons: the first equation itself was wrong, second, it didn't give an exact amount of hydrochloric acid, and he calculated it in moderation, and third, even in moderation, he ignored the gas spill. If the dosage of hydrochloric acid is not stated, there is no solution to this problem.

The equation is 2HCl+Na2CO3=2NaCl+H2O+3H2The molecular mass of hydrochloric acid is, in this equation the hydrochloric acid coefficient is 2, so multiply by 2 to get 73, which is the molecular weight, and then the molecular weight of Na2CO3 is 106, known to be added, then let the mass of hydrochloric acid consumed be x, that is, multiplied by 73 divided by 106 is equal to x, and the solution x is, the known concentration is, that is, the amount of hydrochloric acid consumed is multiplied to obtain. Next is 2Fe + 6HCl = 2FeCl3 + 3H2.

According to the coefficient, the molecular weight of hydrochloric acid is 219, and the actual mass of hydrochloric acid is 112, then let the mass of iron be y, that is, 112 multiplied by 219, which is approximately equal to.

It's very simple, and it seems that there is an overdose of hydrochloric acid, which is a bit complicated.

1 Metal materials include pure metals and alloys, and the most commonly used metal materials are iron, copper, aluminum and their alloys.

2. The use of the substance is mainly determined by the nature of the substance, which is not the only determining factor to consider whether it is cheap and beautiful in appearance.

Saturated calcium acetate solution is added to higher concentration alcohol, and because it is not easily soluble in alcohol, it can precipitate gelatinous calcium acetate containing ethanol, which can be made into a transparent elastic candle ...... a certain shapeCan be lit with fire.

Take a look at the high school chemistry book and the interesting experiments in the back are detailed.

Water chemistry experiments should be easier to do. Such as changes in temperature:

Fill a large glass with cold water.

Fill a small glass with hot water. (Note that the small glass should be able to be placed in a large glass, preferably in a small sip) Put a little color in the hot water, so that the hot water and cold water can be distinguished together.

If you quickly put a small glass of colored hot water into a large glass, you will have a magnificent phenomenon like a volcanic eruption.

First of all, as a boy over 1.8 meters to tell you, our taller boys like to be a little shorter, don't worry about it (laughing liquid first tells you can default to jealousy) Secondly, do more jumping exercises, don't make a fuss about using too heavy objects to oppress! ^_