Junior high school chemistry, help me see if it s right

Fix the answer on the first floor.

2 b The number of protons determines the kind of atom.

4 Let the valency be x, then there is r(oh)xr2(so4)n, and the column formula is 17x+r=m

96x+2r=n The solution gives x=(n-2m) 62

The first 3 questions are correct.

If the valency of r is odd, then set to +x

Hydroxide is r(oh)x

Forming a compound with sulfate atomic clusters: R2(SO4)x has a relative atomic mass of R

then a+17x=m

2a+96x=n

x=(n-2m) (96-17*2)=(n-2m) 62If the valency of r is even, set to +x

Hydroxide is r(oh)x

Forming a compound with sulfate atomic clusters: R(SO4) x 2 Let the relative atomic mass of R be a

then a+17x=m

a+48x=n

x=（n-m）/（48-17）=（n-m）/31

1. c 0 +2 +4 +6 +7

2.b Reflected in aspects such as valency and mobility.

3.d Valence in ascending order -1 +1 x +5 +74(n-m) 31 or (n-2m) 62

1c2b3d

4 Let the valency be x and its relative atomic mass be a. When x is an even number, a+17x=m, a+48x=n is solved (by yourself).

When x is an odd number, a+17x=m, 2a+96x=n, the solution (self-solution) eliminates a

4.Let the valency be x, then there is r(oh)xr2(so4)nn column, and the equation is 17n+r=m

96x+2r=n The solution gives x=(n-2m) 62

Bonus points.

Because the oxygen concentration required for the combustion of different substances is not the same, the oxygen concentration required for firewood combustion is higher, so when the oxygen concentration is reduced to a certain extent, it is not enough to support the burning of wood, so it is extinguished, and the combustion of red phosphorus and white phosphorus, the concentration he needs is relatively low, so after the wood is burned, the oxygen in the remaining air in the gas collector cylinder is enough to support the combustion of phosphorus, so the phosphorus is inserted into it, and the phosphorus will burn, It is also impossible to completely consume the oxygen in the cylinder, and when the concentration of oxygen is lower than the minimum concentration to support his combustion, it will also be extinguished, so to remove the oxygen in the cylinder, you can use a metal oxidation ring to completely remove it.

The reason for this is that a certain amount of oxygen is required for the burning of wooden sticks. When there is not enough oxygen, the sticks are extinguished. Red phosphorus, on the other hand, burns as long as it is aerobic. So after it burns, the oxygen in the air has been completely used up by it.

Good Khan, I'm still a science student, and I've taught everything I learned to the teacher. Cups.

The first question does not state that the reaction is complete with the addition of a sufficient amount of dilute magnesium sulfate, but zinc does not.

The second question shows that with a sufficient amount of dilute sulfuric acid, all three metals can react completely.

The crux of this problem is that the hydrogen produced in Figure A is calculated based on sulfuric acid, the concentration and mass of sulfuric acid are equal, so the mass of hydrogen produced is equal, and the second figure is that the mass of hydrogen is calculated according to the metal, at this time, the amount of sulfuric acid is sufficient, and the smaller the relative molecular mass, the more hydrogen will be produced. The three metals have different relative atomic masses, so the mass of hydrogen produced is also unequal. You must learn to analyze which reactant hydrogen is based on the calculation, and whoever has the sufficient amount is calculated according to another substance.

Fig. 2, there is an excess of metal, all the acids in the reaction are consumed, and the H2 produced comes from H+, and because H+ is the same and is consumed completely, the H2 produced is equal.

Figure 3, acid excess, all metals are consumed in the reaction, and the amount of H+ consumed is related to the properties of the metal, and the H2 produced is not necessarily equal.

The amount of metal in Figure A is sufficient, and the mass of hydrogen produced is all the hydrogen elements in sulfuric acid, because the mass and concentration of sulfuric acid are the same, so the mass of hydrogen produced is the same, and the amount of metal in B is insufficient, and the mass of hydrogen produced is related to the mass of metal elements and the relative atomic mass, and the smaller the relative atomic mass of the metal of the same mass, the more hydrogen mass is produced.

Problem 1: If the quality and concentration of sulfuric acid are the same, the sulfuric acid contains the same hydrogen element, so the hydrogen produced is the same;

Question 2: Although the sulfuric acid is the same and sufficient amount, the given metal mass is also the same, but the three metals have different relative atomic masses, and the smaller the relative atomic mass, the more hydrogen gas is produced. As shown below: