A chemistry problem, a master to solve!! （ ）

It can be found that the concentration of an aqueous solution of sulfuric acid with a density of 1 06 grams at 20 degrees Celsius is almost equal to the amount of zinc.

According to the title, the amount of sulfuric acid and the amount of zinc are exactly the same, and the zinc sulfate is generated.

ZnSO4 molecular weight.

Water molecular weight 18

Molecular weight ZnSO4 + 7H2O=

20g___x___yx=y=

This is the amount of water left, which can be calculated if you know the solubility at 10 degrees Celsius.

In fact, there is a density, you can check the table to know the mass fraction of sulfuric acid.

I checked the density of 1 06 grams per milliliter of sulfuric acid with a mass fraction of about 10%.

But there are still few conditions.

There is no solubility.

Refute the first floor, I have done it dozens of times in the third year of high school, and I am only in the third year of junior high school.

If someone asks you, if you don't answer, forget it, don't ggyy.

Why do I think the conditions are not enough, no concentration, no solubility.

Just give so many points and want detailed steps, it's not enough for me to bother, it's a very simple question, I did dozens of questions in my junior year of high school.

First, write the chemical equation, then calculate the relative atomic mass of each substance, and then calculate the proportional equation according to the principle of conservation of mass to find the resulting mass.

The above methods can be used for the calculation problems in the third year of junior high school.

Ho ho, chemical symbols are hard to play! ~~

I can't do it! What a subject!

The conditions are indeed less, and the solubility of zinc sulfate at 10 degrees Celsius is not known.

Acidic oxides: CO2, NO2, N2O5, SiO2, P2O5, SO2, SO3, CRO3, Mn2O7

Basic oxides: Na2O, MGO, Li2O, K2O, CaO, Bao, CuO, FeO.

Note: Na2O2 is not a basic oxide because O2 is released when it reacts with acids; Al2O3 is an amphoteric oxide because it reacts with both acids and bases to form salts and water.

Acid oxides CO2, N2O5, SiO2, P2O5, SO3, Cl2O7, Mn2O7

Basic oxides Na2O, MGO, CAO

Acid Oxides:

co2，so3,no2,n03

Basic Oxides:

cao,na2o,mgo,al2o3,

Acid oxides: CO2, SO2, SO3, NO, NO2

Basic oxides: Al2O3, Na2O2, MGO, CAO, Feo, Fe2O3

That's basically what they're most commonly used for.

Calcium carbonate reacts with two HCl molecules.

2 HCl molecules, so 2 CLs will be supplied

Ca is +2 valence, Cl is -1 valence, one Ca needs two Cls, which is the reason why CaCl2 is 2.

Good luck with your learning and progress.

cacl2

2 is obtained based on the valency.

Calcium +2, chlorine-1, to make the algebraic sum of valency to 0, so chlorine has two.

Also, point out that there is a problem with your chemical equation. The correct one should be:

caco3+2hcl===cacl2+h2o+co2

Because the Ca ion is positive bivalent, and the chloride ion Cl is negative monovalent, the requirement for writing the chemical formula is that the algebraic sum of the valence is 0, so the 2Cl ion can be combined with a Ca ion to achieve the algebraic sum of 0, so there is a 2

I'm glad to answer your questions and wish you progress in your studies!

Ca (calcium) is a divalent cation, and Cl (chlorine) is a monovalent anion;

The compound is not charged (electrically neutral), so it is CaCl2.

The chemical formula should be written according to the valence, using the algebraic sum of the positive and negative valencies in the chemical formula to write as o, because the valency of calcium is +2, and the valency of chlorine in chloride is -1. In fact, this problem is easy to deal with, you only need to memorize the valency of common elements in junior high chemistry.

At first glance, it is a junior high school student, and it should not be H2CO3, but H2O and CO2. I'm curious, if you doubt the 2 of CaCl2, why don't you doubt the 2 in H2CO3?

Ca is a positive 2 valence, CL is a negative 1 valence, and the sum of positive and negative prices should be 0

The valency of calcium is +2, chlorine is -1, the whole substance is neutral, according to the simplest ratio, the chlorine subscript is 2

1. Since they are all just saturated, the ratio of solute to solvent mass is the same.

So, m 100 = (160n 250) (100 + 90n 250)2, na2o + h2o = 2naoh

c = cholelum. c=10×16/25/100=

Sodium chloride. c=10/100

cao+h2o=ca（oh）2

c=3, it is possible to form gases or precipitates, and these substances are detached from the solution.

4. When it is evaporated, it must be a saturated solution.

So s=

1. The mass of pure CuSO4 in NGCUSO4·5H2O should be equal to mg CuSO4, and the mass of pure CuSO4 in NGCUSO4·5H2O is 16/25N, therefore, the relationship between M and N is that M is equal to 16/25N

2. Sodium oxide, sodium chloride, bile alum, calcium oxide.

3. Because some capacitance can react with water, such as sodium oxide, the mass fraction formed is greater than 100% a, and the maximum soluble x in gram water is gram, then the maximum soluble gram in 100 grams is 60 grams, and the solubility of substance x is 60 grams at t degrees Celsius.

Homework someone else will write for you.

Does your wife want someone else to do it for you?

1. It can be calculated according to the algebraic sum of the valency of the compound to zero

The ratio of the amount of iron and oxygen is 4:5, which can make iron and oxygen 4mol and 5mol respectively, let Fe2+ be xmol, then Fe3+ is (4-x)mol, according to the valency algebra of the compound, there is: 2x+3*(4—x)=2*5, and the solution of x=2 is x=2, then the ratio of Fe2+ to Fe3+ is 1:

12. The ratio of the quantity of Fe2+ to Fe3+ is 1:2, then the ratio of FeO to Fe2O3 is 1:1

Fe GFE2O3 is 3mol Fe3+ The amount of Fe3+ is 6mol, and when the catalytic activity is the highest, the ratio of Fe2+ to Fe3+ is 1:2, that is, the amount of Fe2+ is 6mol*(1 3)=2mol The amount of Fe3+ is 6mol-2mol=4mol

That is, the amount of FeO and Fe2O3 is 2mol respectively; 2mol and 2Fe2O3 + C = = = = 4 Feo + CO2

xmol 2mol

The solution is x= so the mass of the toner is 12g mol*

1.Let the quantity of Feo be x The amount of Feo is y and we get x+2y:x+3y=4:

5 The solution yields 2y=x, i.e., mfeo:mfe2o3=2:1, so the ratio of the amount of feo to fe2o3 is not 2:

The relative molecular mass of 1 is 56 O is 16, the ratio of the amount of Fe2+ to Fe3+ in the catalyst is 1:2, and the mass fraction of Fe is 56x3 (56x3+16x4).

3.From the equation, it can be seen that the amount of matter that consumes 1molc to produce 4molFeO 480GFE2O3 is 3mol, that is, to produce FeO2mol, it can be found that it consumes 6g

1.Right "Left" ".

2. Oxygen and hydrogen.

3. Oxygen: Put a small wooden strip with sparks deep into the gas, and the re-ignition of the wooden strip can prove to be oxygen hydrogen: block the test tube filled with gas with your hand and get close to the flame, if you hear a crisp popping sound, it proves to be hydrogen.

4. Hydroxide.

(2) hydrogen is produced in the test tube connected to the positive electrode; What is produced in the tube connected to the negative electrode is oxygen gas; The ratio of the number of molecules of these two gases is 2:1.

3) How to prove these two gases experimentally.

A test of hydrogen is found in the book p47 Martian wood strips for oxygen, and the re-ignition is O24) Through the above experiments, it can be shown that water is composed of hydrogen and oxygen.

Hello, maybe you missed something in this question!

According to the conditions proposed by the molar volume of the gas, it can be seen that at the same temperature and pressure, the molar number is proportional to the volume of the gas. So we get the following equation:

nxoy+ycu=

The gases before and after the reaction are nxoy and n2, respectively, as long as the nitrogen oxides with x=1 are eligible.

That is, both no and no 2 are eligible.

Hope it helps, thank you.

NO2, because 4Cu+2NO2=4CuO+N2, the ratio of the coefficients of the equation is equal to the ratio of the quantity of the substance, so there is NO2 before the reaction, i.e., 1mol, so there is N2 after the reaction

First of all, because nitric acid is more acidic than sulfuric acid, and does not meet the conditions of the same reaction as sulfuric acid (need to be heated), so copper first reacts with and only with nitric acid to release colorless gas NO, and a small amount of nitric acid (copper reacts with excess nitric acid to form NO2 reddish-brown gas) and finally adds excess iron powder in the pot, and only hydrogen gas is released, indicating that copper has completely reacted with nitric acid, and finally the hydrogen ions in the solution are exhausted. In fact, from the ion equation of copper and a small amount of nitric acid, it can be seen that 3Cu + 8H + + 2NO3-= 3Cu + + 2NO (with gas symbol) + 4H20 The ratio of hydrogen ions to nitrate ions is 8 to 2, but the ratio of H+ to N03- in nitrate HN03 is 1 to 1, the problem arises, as long as the outside world provides hydrogen ions, it can continue to react with the remaining nitrate ions and copper. Until all nitrate ions are depleted.

This question is the case where sulfuric acid provides hydrogen ions. And it can be calculated that the h+ that reacts with iron is divided by 2 and then multiplied by 2, and the reaction is required, so it can be judged that the hydrogen ions in the solution have common hydrogen, and the nitrate ions only react with copper, because no nitrogen oxides are released when the solution reacts with iron later. So there is nitric acid in the solution, and sulfuric acid is the equivalent of nitric acid, and I hope the solution will be useful to you.

In the presence of nitric acid, no metal will produce H2 from it. So HNO3 must have finished reacting.

To say that H2SO4 participates in the reaction with Cu is essentially H+ participation in sulfuric acid.

In fact, this problem is mainly explained by ion reaction, after the reaction between Cu and Hno3 is complete, Cu(NO3)2 will be generated, at this time, H2SO4 can provide H ions Cu(NO3)2 provides NO3 ions, which is equivalent to nitric acid again. In fact, the answer to this question may also be explained according to your current knowledge. Remember, adding soluble nitrate under acidic conditions is equivalent to adding nitric acid.