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h2so4 + zn = znso4 + h2 ↑200* m m=

1mol H2 is 2 grams, grams are, and the number of molecules in 1mol is 02mol for.

In standard conditions (1 atm, 0 atm), the density of hydrogen is grams v = mass density = liters per bottle, and 9 collecting cylinders are required.

h2so4 + zn = znso4 + h2 ↑m=200g*

n sulfuric acid = MH2 = n sulfuric acid * 2 =

2）n=3）v=

8960 500 is approximately equal to 18

18 gas collection cylinders are required.

1)n(h2so4)=(200*

According to H2SO4+ZN=ZNSO4+H2

n(h2)=n(h2so4)=

m(h2）=n(h2)*m(h2)=

2) n=na (constant. Check it up in the book) * n = ......

3) n (one bottle) = v Note the unit conversion, all into liters) = n (bottle) = one bottle) = so it's nine bottles.

According to the chemical equation of magnesium and sulfuric acid. Under standard conditions, the gas is, so is magnesium, the mass is, and after the reaction, MgSO4 is, then the amount concentration of the substance is.

It seems that you are learning the content of chemistry on your own, which is very good, the content of the quantity of matter is more difficult, and you should do more exercises on the basis of understanding the concept, but at present, you have not fully understood the relevant concepts. Let's take a look at the relevant counseling governance.

（1）mg+h2so4=mgso4+h2

The amount of the substance of mg is:

The molar mass of magnesium is 24,,,m=mn,m=

The quality of copper is.

2) by the above equations.

The amount of the substance of MgSO4 is:

c = negative cubic ) = 1 (mol l).

(1) First of all, it is necessary to determine that the reaction is mg, and cu does not react, and then the equation is listed: mg+h2so4=mgso4+h2

Since h2 is, so is, so the corresponding mg is, m(mg)=, so cu=(

2）c（mgso4）=n/v=

Copper is 25% by mass

The concentration of the MgSO4 substance is 1mol L

Only magnesium reacts with dilute sulfuric acid to produce hydrogen, and the mass of magnesium is calculated according to hydrogen, so copper is, the mass fraction is 25%, and the same magnesium sulfate is obtained, divided by 200ml to the amount concentration of the substance 1mol l

It's so easy. If you ask the quantity of magnesium first, you can find the quality of copper. Second, the quantity of the substance can be counted by the equation, and then its concentration can be found by the formula.

25% 1mol/l

Copper does not react with dilute sulfuric acid, and magnesium reacts with dilute sulfuric acid in a ratio of 1:1.

Liquefaction The intermolecular distance becomes larger.

Decomposition Decomposition reaction.

Compound Compound reaction.

Evaporation increases the molecular spacing (yes to this particle knowledge).

Relative molecular mass of organic matter = 30

Organic matter 24 g completely combusted, generated and under standard conditions), the mass of the substance of h = , the amount of the substance of c = , the amount of the substance of o = (

Organics: C:H:O=24:2:4:2, and the molecular formula of this organism is C2H4O2

It is also known that this organic substance is weakly acidic, can react with metal sodium, can also react with alkali solution, the organic matter is acid, is acetic acid CH3COOH.

The uses of the following substances are related to their chemical properties: (c) a use of metal mercury as a liquid in the thermometer - thermal expansion and contraction, physical properties b use liquid nitrogen to remove small tumors and moles on the face - liquid nitrogen cooling, physical properties c carbon dioxide as a greenhouse gas fertilizer - photosynthesis, chemical properties d use of marble as a decorative material - hardness, smoothness, physical properties.

CCO2 is the raw material for plant photosynthesis, plant photosynthesis produces oxygen, so it is related to chemical properties, and the other three are based on physical properties.

I hope to help you, if you have any questions, you can ask

I wish you progress in your studies and go to the next level! (*

Ca is the principle of thermal expansion and contraction of mercury, B is the use of liquid nitrogen vaporization process to absorb a large amount of heat, which plays the role of anesthesia, and D has nothing to explain.

a is oxygen.

b is sodium.

c is for nitrogen.

d is aluminum.

1) N3N ion crystals (2) Na:O::O:Na(3)O>Al>N>Na, (4)H2NO3+2NaHo=2H2O+Na3(5)Na

An element whose ordinal number is equal to 3 times the number of periods A is the second period, the sixth main group, and a is oxygen.

b Elements whose period number is equal to 3 times the ordinal number of the group b are the first main group and the third period b is sodium.

c At room temperature, the gas element is a diatomic molecule. The gaseous hydride of C can make the phenolphthalein solution red, and C is nitrogen.

d The third cycle of the metal element, which can react with the hydrate corresponding to the most ** oxide of b to form hydrogen d is aluminum.

1) Write the elemental structural formula of the formation of element C N2, the hydrate corresponding to the most ** oxide of element C reacts with the gaseous hydride of the element, and the resulting product belongs to ionic crystals. (2) Elements B and A can form compound B2A2, write the electronic formula of the compound (3) The four atoms are in the order of atomic radius from large to small (fill in the element symbol) (4) Write the chemical equation of the hydrate corresponding to the most ** oxide and the most ** oxide corresponding to B. (5) Compared with elements b and d, the stronger metallicity is na (fill in the element symbol).

(1) Write the elemental structure formula of the formation of element C: , the hydrate corresponding to the most ** oxide of element C reacts with the gaseous hydride of the element, and the resulting product belongs to (ionic) crystals.

2) Elements B and A can form compound B2A2, write the electronic formula of the compound: .

3) The four atoms are in order of atomic radius from largest to smallest: na, al, n, o (fill in the element symbol).

4) Write the chemical equation for the reaction of hydrate corresponding to the most ** oxide and the most ** oxide corresponding to b:

Al(OH)3 + NaOH NAALO2 + 2H2O(5) elements B and D are more metallic: NA (fill in element symbol).

A is oxygen, B is sodium, C is nitrogen, D is aluminum, (1) N (three **) N, ionic crystals, (2) electronic formula of sodium peroxide, 3) Na>Al>N>O, (4) Who's the most ** (5) Na

1.Unchanged, changed.

2.(1) When the temperature is high in summer, the gas in the tire will expand due to heat (the distance between the gas molecules increases) due to heat, and it is easy to burst the tire.

2) The first is a physical change, where the water molecule does not change.

The other is a chemical change, where water molecules are altered and converted into hydrogen molecules and oxygen molecules.

1. No change Change.

2. Thermal expansion and cold contraction.

One is a physical change and the other is a chemical change.

1. I can't do it all so easily, and I definitely didn't attend the class. If you don't have a good foundation in chemistry, you will definitely regret it in the future.

1.Hydrogen mass = ( g=

fe + h2so4==== h2↑ +feso456 2x

m(fe)=x=

2.The solute in solution is FeSo4 = 152 =