Chemistry questions qualified analysis process Thank you!

2kClO3==2kCl+3O2, the catalyst is Mno2, no longer producing gas means that Kclo3 has been relied, and the residual solid is a mixture of Mno2 and KCl. When adding water only.

KCL dissolves, and according to the title, there is no KCL that is not dissolved in the end. The solubility can be deduced from the process of adding water twice, and the mass of the mixture can be calculated from the solubility and the first addition of water, according to the mass of the mixture.

The amount of oxygen produced can be known, and the mass of Kclo3 and Mno2 corresponding to the reaction can be calculated.

1.The addition of water dissolves the solids, that is. The solubility is water.

2.The mass of the solid dissolved by adding water for the first time is 15; So the mass of residual solids is, and the mass of oxygen generated is.

According to the chemical formula, m(kclo3)=245 96 is obtained.

Hello, we must first know: CuSO4 solution is blue (the color of Cu2+), Cu elemental is purple-red, and the composition of patina is basic copper carbonate (this understanding).

The rusted copper sheet must contain Cu elemental and patina, and the reaction of patina and sulfuric acid will produce Cu2+ and CO2, so the blue solution is CuSO4, the purple-red solid is Cu (which is characteristic of these two substances), the colorless gas is CO2, and the solution D is ferrous sulfate (simple displacement reaction).

1. In the reaction: Cu2(OH)2CO3+2H2SO4=2CuSO4+3H2O+CO2 (gas).

Among them, CuSO4 is dissolved in water as a blue solution.

Because there is still copper element in the copper sheet, and the copper element does not react with dilute sulfuric acid, the purple-red solid is Cu.

I haven't studied for many years, the rusty copper sheet contains copper, copper oxide, and possibly cuprous oxide, which is oxidized by a large amount of dilute sulfuric acid c b a is copper copper sulfate oxygen, middle school chemistry generally mentions that the blue solution is generally copper sulfate solution, copper is purple-red, copper sulfate solution + copper is reduced after a large amount of iron powder, solution d is iron sulfate solution.

You're asking about important aspects of the physical properties of common substances to keep in mind.

Copper oxide is reacted with dilute sulfuric acid ......

This question lacks conditions, but the idea should be fixed, since this question has already told you the specific mass of dilute hydrochloric acid, you can see if it is completely reacted and the mass of the gas produced. If the reaction is complete, the mass of HCl reacting with magnesium carbonate and calcium carbonate can be deduced from the amount of carbon dioxide produced, and the mass of the remaining HCl is the amount of reaction with magnesium hydroxide, and the mass of magnesium hydroxide can be deduced.

If the mixture is calculated as carbonic acid, it needs 2 times the molar number of hydrochloric acid, and if the molecular weight of calcium carbonate is large, for example, 10g is required, and the mass of hydrochloric acid is required.

0 09991mol 2, the mass of hydrochloric acid added is, so hydrochloric acid is excessive, and then the number of moles of carbonate is calculated according to the amount of carbon dioxide released.

There is a problem with this question, hydrochloric acid not only reacts with magnesium hydroxide, but also with carbonic acid

There are no known conditions for this topic, and the solid is thrown in, and the reaction result is not said, so you dare to find the mass of a substance in the mixture? I know if these solids are dissolved or not, and whether they are fully reacted? Excess hydrochloric acid or mixture or just complete reaction?

Insufficient conditions. The biggest difference between magnesium hydroxide and the other two components is that the latter is a carbonic acid and ion, which can react with hydrochloric acid to release carbon dioxide gas. So the amount of gas emitted is missing from the question.

Knowing this, just knowing the total amount of magnesium carbonate and calcium carbonate, there is also a condition, which should be the amount of sodium hydroxide added to generate precipitation, and the amount of magnesium hydroxide can be found together.

At the very least, you should be told the quality of the remaining solution, or how much gas is produced. Important conditions are therefore missing and need to be supplemented.

The answer is 0 g

Magnesium hydroxide, magnesium carbonate, calcium carbonate of the same quality, magnesium hydroxide consumes the most hydrochloric acid. According to the calculation of 10g of magnesium hydroxide, the actual consumption of hydrochloric acid hydrochloric acid, the quality of the hydrochloric acid solute is seen in the title, which represents the excess hydrochloric acid and can be completely rejected. So the answer is 0g

Acid-base reaction first, first assume that they are, see how much HCl is needed, HCl is excessive, then in the end it is all mgCl2, the answer is 0g

The problem cannot be solved without conditions.

You can solve the problem by listing the equations according to the conditions given in the problem, and then according to the knowledge of conservation of elements.

Lack of conditions, can only go so far.

You want to first write down the conditions in the question, or.

It's you who think about it yourself and then ask, and you're right.

bar. Lack of conditions can not lead to results, ideas.

can give you that the chemical change in the formation of gases.

How much is the essence of the question, the idea is as follows, you can understand it yourself and then use your brain.

The question is incomplete, please ......Complete supplements, otherwise they cannot be calculated.

Chemistry is a kind of natural science, which studies the composition, properties, structure and change laws of matter at the molecular and atomic levels. The science of creating new matter. The world is composed of matter, and chemistry is one of the main methods and means used by human beings to understand and transform the material world. It is a discipline with a long history and vitality, and its achievements are an important symbol of social civilization.

Title: Add 10 g of magnesium hydroxide, magnesium carbonate and calcium carbonate to a mixture of dilute hydrochloric acid ,...... with a solute mass fraction of 10%.Then the mass of magnesium hydroxide in this mixture is g?

Please ......Complete the complement.

Kao, this is a junior high school question???

The current education is speechless!!

I really don't, but I feel like there's nothing missing.

bt Don't think about it.

Give up decisively You don't even need to look at this kind of question.

Crash directly.

I was taught to by an older brother I knew who was very good at chemistry.

a:hno3 b:naoh c:h2o

d:c e:co2 f:h2 g:ba

h:bao i:cao j:ca

k:o2 l:cu m:cuo n:h2so4

o:na2co3 p:ca(oh)2 q:fecl3

r:fe

Little brother, I'm from the past, I don't take such a question in the high school entrance examination, are you competing?

It's a bit of a test, I'll definitely help you figure it out.

This question examines the properties of common elemental substances.

According to "A burns in the air and emits a dazzling white light, forming a white solid C", it can be judged that A is a mg element, and C is MGO. According to "A+B--C", B is O2 elemental.

According to "A+H--F+I (i is a gas)", it can be associated with the reaction of mg with acid to form hydrogen, so i is an element of H2; It is then judged that H is an acid, and F is a salt formed by Mg and H.

According to the analysis of "C+H--F+E", C is MGO, H is acid, F is salt, then E must be H2O.

In this way, "b+i--e" and "e--b+i" are verified.

The key is the condition of "G+H--F+E+D (D is a gas)", G contains Mg, and reacts with H (an acid) to form F (a salt of Mg), E (H2O) and a certain gas D (excluding H2), it can be seen that G itself contains a weak acid group, which reacts with H to form a colorless and odorless gas anhydride, which is easy to determine that this is carbonate (colorless and odorless excludes SO2). Therefore, d is CO2. Then depending on the presence of water in the product, then g is the basic carbonate.

Answer: (1) The chemical formula of substance A is: mg

2) Write the chemical formula of another substance with the same composition elements as the E substance: H2O2

3) Write the chemical equation for d to be converted to b under certain circumstances:

Did you copy the wrong question? ）

4) A and D can undergo displacement reactions under high temperature conditions, and the chemical equation of the reaction is written

2mg+CO2 = (high temperature) = 2mgo+c

I'm sure you've copied the wrong question, because B is a elemental substance, and D is definitely a compound ("A and D can be replaced at high temperatures, how can they be replaced if they are not compounds?"). So d can't be converted to b. But the ideas are clear to you, just understand!

Damn, I won't graduate from engineering,, I still got a full score in chemistry in the high school entrance examination that year, hey.

The answer should be wrong.

The mass of 100t of hematite containing 20% impurities containing Fe2O3 is 100*(1-20%)=80t

Suppose the mass of pig iron that can be smelted up to 96% iron is x.

Fe2O3 + 3Co = High temperature = 2Fe + 3CO2160 11280T 96%x160 80=112 96%x

x = A: Pig iron containing up to 96% iron can be smelted.