A few questions about high school chemistry

1, Na2CO3 + CO2 = 2NaHCO3, so A is not good, if it is not saturated, there will be the above reaction.

2. Look at the stem of the question, the solute concentration increases, not the weight of the solution increases.

3, According to the conservation of elements and mass, the solute is Naoh, according to the conservation of elements, the mass is 8g, the reaction releases H2, according to the conservation of mass, the mass of the solution is, and the answer is obtained.

4. Have you ever learned the equation of state of an ideal gas, pv=nrt, it is obvious that t, v are constant, so n increases with the increase of p, I have not learned and have not remembered in advance.

5. Let the amount of Na2O substance be X, Na2O2 is Y, then X+Y=, according to the reaction equation Na2O+2HCl=2NaCl+H2O, 2Na2O2+4HCl=4NaCl+2H2O+O2 (can be regarded as reacting with water first, and reacting with hydrochloric acid), if the mass of O2 is known, the answer can be obtained according to the conservation of mass, so this question lacks conditions.

6. According to the conservation of charge, R is used as a reducing agent, which is oxidized, and the monovalent is increased, and O2 is used as an oxidant, which is reduced, and the 4 valence is reduced, so m=4

I just want to say, boy, if you really want to figure out chemistry, let's go to the competition.........High school chemistry is stuck in textbooks, and there are many things that have to be forcibly accepted.

But you're just a freshman in high school, and you'll understand a lot of things as you learn.

1.Because NaHCO3 is generated after passage A

Does not react with CO2.

I can get 8gnaoh. But the reaction is generated.

1 Because saturated Na2CO3 will absorb the CO2 produced to form NaHCO3, saturation is required to maximize the absorption of hydrochloric acid.

2 b The precipitate formed by the reaction with carbon dioxide will no longer be part of the solution, and this reaction consumes calcium hydroxide, so the solute concentration decreases.

3 I'll give you an idea. First list the chemical formula of the reaction between sodium and water, calculate the amount of water consumed by gram sodium and the amount of sodium hydroxide generated, the solute mass is the mass of sodium hydroxide produced, and the mass of the solution is the mass of sodium plus water (because the mass of the element before and after the reaction is conserved).

4 In this popular understanding, the pressure is 5 times because I compressed the things that can be loaded in 5 spaces into 1 space, so the mass of the things in it should be multiplied by 5. Is this explanation acceptable?

5 I forgot what Moore was

1, Na2CO3+CO2+H2O=2NaHCO3, so A can't work; If NaHCO3 is not saturated, CO2 will dissolve more in it, and the reason for this will be understood when you learn the principle of balanced movement.