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The chloride obtained from the title is MCL2

and the mass fraction of chlorine is , then the molecular mass of mcl2 is (i.e., the atomic mass of m is 24That is, mg.

That is. That is, ie.

Therefore, the hydrochloric acid mass fraction is.

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Hello, this is the whole process, I am also the third year of junior high school, I don't know how to ask, but you can send me a private message.

Let the metal be m, then the equation is.

m+2hcl＝mcl2+h2↑

Then the mass fraction of Cl in MCL2 is .

The relative molecular mass of MCl2 is 71

The relative molecular mass of M is 24, and the mass of HCl is X

m + 2hcl＝mcl2+h2↑

x24 x = hydrochloric acid mass fraction is.

1. an iron frame platform; gas collection cylinders;

2. Check the air tightness of the device; Method: After installing the device, put the mouth of the trachea into the water, hold the container tightly with both hands, if you see bubbles coming out of the trachea, it proves that the device is airtight;

3. [In order] a; b；Drainage method or upward exhaust air method; The reasons are: oxygen is not easily soluble in water and oxygen is denser than air.

Step 1: Roll the paper into strips, light it, and cover it over the flame with a dry and cold beaker;

Phenomenon 1: If there is a colorless mist on the inner wall of the dry and cold beaker;

Conclusion 1: Prove that water is generated when paper is burned;

Step 2: Again, roll the paper into strips, light it, and cover it above the flame with a beaker coated with clarified lime water on the inner wall;

Phenomenon 2: If the inner wall of the beaker is clarified, the lime water becomes turbid;

Conclusion 2: Prove that carbon dioxide gas is generated when paper is burned.

Carbon element: Collect the gas after the paper is burned, pass it into the clarified lime water, become turbid, and there is carbon dioxide, there is carbon element.

Hydrogen: Ignite paper in a large beaker with a mist of water on the walls of the cup, with hydrogen element.

Light the paper and place the large dry beaker above the flame; Small water droplets were observed on the beaker and it was concluded that there was hydrogen.

Light the paper, dip the large beaker in clarified lime water and buckle it above the flame; **, becomes cloudy; Conclusion: There is carbon.

1. Light the paper with a match, and cover the beaker with clarified lime water on the paper on the inner wall, and the phenomenon of clarified lime water becomes turbid, and the conclusion is CO2

2. Put the lit match into the beaker, phenomenon: water droplets appear on the inner wall of the beaker, and the conclusion is h

1.The paper was lit with a match and the drier beaker was placed above the flame, and small water droplets were found on the inner wall of the beaker, indicating that the paper contained hydrogen.

2. Light the paper with a match, then dry the inner wall of the beaker, coat it with clarified lime water, cover the beaker coated with clarified lime water above the flame, and find that the clarified lime water becomes turbid, which proves that the dry paper contains carbon.

The principle is to ignite the paper piece, and the generated gas is passed into the clear lime water, and if a white precipitate is produced, the paper still has carbon element; Light the piece of paper, cover the flame with a beaker above the flame, if there are colorless water droplets on the inner wall of the beaker, the paper also has hydrogen.

The square state excavation sail mill nucleus is shown in the downstream silver chart.

<> the answer to which oak hole plum withered picture is as wide.

Forehead. I'm a junior in high school, but I'm blindsided when I see this question, so abstract? What is the concept of energy conversion of adjacent matter?

17% Al2O3 3% Fe2O3

The easy way to solve this kind of problem is to directly set 100g of purple sand to sue Kai. then there are 17gal2o3 and 3gfe2o3

There are 9gal, 8go in the calculation. Then the mass fraction of Al is 9 100 = 9% and the mass fraction of O in Al2O3 is 8 100 = 8%.

Count Fe2O3The mass friend bond of Fe in 3Gfe2O3 and the mass fraction of O of Fe2O3 are called.

The mass fraction of O in Fe2O3.

The mixed solution of 200ml, the copper sulfate concentration of 1moll-, means that the copper sulfate concentration in 200ml of mixed solution is 1moll-

That ncuso4=, consume Naoh, CH2SO4=, CH+=, consume NaOH, consume a total of 24 grams.

co, cu (superscript 2+), fe2o write superscript) 12, c d

Oxygen is isolated.

Molecules are in constant motion.

Potassium fertilizer. I can't see it in the back...

You don't say which question it is!!

Question 11: Positive bivalent, Cu2+ (2+ is the upper corner mark), Fe2O3 (2 and 3 are the lower corner mark).

12 Questions: (1) C, (2) D, (3) Isolation of oxygen.

1.for iron and copper, ferrous chloride.

2.Copper, ferrous chloride and copper chloride.

[excess] of iron powder is added to the CuCl2 solution, and after a full reaction, it is filtered, and the solids on the filter paper are iron and copper, and the solute in the solution (the dissolved substance is called the solute) is FeCl2;

2.[A small amount] of iron powder is added to the CuCl2 solution, and after the full reaction, it is filtered, and the solid on the filter paper is copper The solute in the solution (the substance to be dissolved is called the solute) is CuCl2

and FeCl2

The reason is that iron is more reactive than copper, and the copper in the CuCl2 solution can be displaced, and the iron itself becomes FeCl2

1、cu、fe;(excess iron powder); fecl2;

2、cu；CuCl2 (overdose) and FeCl2