Chemical calculations Haha, how to calculate chemical rU m

Is the standard answer so much?

I'm not sure I'm right.

I'll tell you about my thoughts, you can see if you can:

Suppose the solution mass of BaCl2 is X and the solution mass of Na2SO4 is Y

Then the mass of the solution after the reaction is: X+Y-mbaSo4The question says that it is equal to the mass of the BaCl2 solution added dropwise, so x+y-mbaso4x

After sorting out, knowing the mass y of Baso4 reflected in this way, it is easy to do, and then using the chemical equation, the mass of Na2So4 can be calculated.

142y／233．

The mass of the Na2SO4 solution has been set to Y

So it has a mass fraction of: 142 233

The friend upstairs is very smart, and the answer is correct, but the method is a bit problematic, a bit opportunistic, and in fact the reaction will not be exactly like that, although the answer is correct.

Can you be sure that Na2SO4 happens to react completely? Does the quality of the final solution have to be the quality of NaCl? So, the method is a bit problematic.

You're talking about the same mass of the precipitate as the dropwise addition of BaCl2 solution, right?

According to the title, then the mass of the Na2SO4 solution is the mass of the precipitate, and if the precipitate is 233, then Na2SO4 is 142

The mass fraction of Na2SO4 solution is about 142 233 I don't know if it's right, forgive me if it's wrong.

Consider what happens when the reaction is just complete.

We can see the change in the quality of the BaCl2 solution.

The mass of BA is reduced to 137 m, the mass of Na is increased by 46 m and the mass of water in the Na2SO4 solution is set to X

The quality remains the same as the original

137m+46m+x=0

x = 91 mNa2SO4 solute mass: 23 m * 2 + 96 m = 142 m total mass: 91 m + 142 m = 223 m

The result was: 142 233

δrum=δrhm-δ(p*v)=δrhm-δnrt

rum=δrhm-δ(p*v)=δrhm-δnrt, you didn't calculate water, water is a gas, so δn=5, the answer is.

The historical origin of chemistry is very ancient, and it can be said that the earliest chemical practice began when humans learned to use fire. Our ancestors drilled wood to make fire, used fire to bake food, kept warm on cold nights, drove away wild beasts, and made full use of the glow and heat phenomenon when burning. At the time, it was just an accumulation of experience.

The formation of chemical knowledge and the development of chemistry have gone through a long and tortuous road. It develops along with the progress of human society and is the inevitable result of social development. And its development promotes the development of productive forces and the progress of history.

It is found by the conservation of mass (conservation of elements).

The mass of iron oxide is weighed at 10g – according to the title, it contains impurities.

The total mass of iron oxide and glass tube is 60g - the mass of the glass tube is obtained 50g after a complete reaction, and then cooled to indicate that the oxygen element has been completely gone, leaving only iron and impurities.

So the oxygen element mass is 60

Then the question becomes how much g of iron oxide (Fe2O3) contains oxygen, and it is asked.

Ask Iron Oxide Mass Fraction – Find it using the mass fraction calculation formula.

Refer to the above.

feh2so4

feso4h2↑

56g...

x...The rest of the masses are Fe and Fe2O3, and they happen to satisfy a certain relationship.

fe2o3+3h2so4=fe2(so4)33h2o..fe2(so4)3

fe3feso4

fe~~~fe2o3

m(fe2o3)=(

Total mass of fe:

m(fe)=

2) In the end, only FeSO4 was in the fuel book, and all SO42- ions came from H2SO4

c(H2SO4) = (32g 160g mol*21mol Pihong L

According to the title, sulfuric acid happens to be completely Songyou reaction, and iron powder reacts with ferric iron to form ferric iron in addition to hydrogen gas with sulfuric acid. Assuming that the mass of iron powder is x, and the mass of iron oxide is y, then x+y=

Conservation of mass. x 56 (the amount of total iron substance) and the amount of iron substance used by sulfuric acid to produce hydrogen gas) cover letter = y 160 (amount of iron oxide substance) The amount of iron and ferric iron substance is 1:2

One iron oxide contains two ferric ions.

Solving the equation yields x

y. There is a little trick in the second question after calculating the first question, that is, according to the meaning of the question, it can be known that there is only ferrous sulfate in the final solution, so the amount of sulfuric acid can be calculated by using the amount of iron and the amount of sulfate 1:1, and the amount of sulfuric acid divided by volume is the concentration of the substance.

110,000 tons is the total weight of the alloy, which contains 11 90% of the iron mass reaction. 3co—— 2fe

x 11×90%

to find x

Solution: Let the mass of FeSo4 be X.

M sulfuric acid M liquid H2SO4%=

fe+h2so4==feso4+h2↑

x = A: The mass of Feso4 that can be prepared is .

First calculate the mass of sulfuric acid: m=

In the calculation according to the chemical equation:

h2so4+fe

feso4+h2

x98 gets x=

5 13570 mol 10 ml = 1357l i.e. Qinyou: 5g The drug is prepared into 1357L, and the concentration of the solution is: 10 M L

13570 mol 20 ml = i.e.: 5g of the drug is prepared, then the concentration of the solution is: denier wheel 20 m l

m=n*m, under the premise of matching 1l, is known as a god.

10 ml of lysophyllum requires 10*

In the same way, the need for a loss of 20 ml.

You can use the formula n=m m=5

c=n v, substituting the trace loss-related value hail slip into the Yuanzhou wax.

na2co3+cacl2=2nacl+caco3↓106 2* 100x y 10g

x=,y=i.e., the mass of sodium carbonate=

Let the total mass of the sample be zg

∴z=11g

Mass of sodium chloride =

na2co3+cacl2===2nacl+caco3↓106 111 116 100

x y z 10g

x=y=z=the mass wg of NaCl in the original sample

5%（100+w=