High School Chemistry Calculation Questions Urgent!! ） 5

The reaction is 2Al+6HCl=2AlCl3+3H2Al, the mass of HCl is 12*90%=, and the mass of HCl is 150*2 ALl + 6 HCl= 2 AlCl3 + 3 H2, assuming that AL reacts all, then.

Al is all reacted to the only HCl needed, and HCL is excessive, so AL is used to calculate.

2 al → 3 h2

The reaction produces H2,V(H2)=2*=2Al2Al3+

The reaction produces Al3+, mol Al3+

So the concentration is = 1mol l

1) Al is, HCL is greater than, so Al reacts completely. To produce hydrogen, 2) Al3+ is, so it is 1mol l

Because 12* is less than divided.

2al+6hcl=2alcl3+3h2

12* divided by 27*

According to the law of conservation of elements, 12* divided by 27 divided by each liter.

Landlord, to be honest, the question is very obscene!! If it's very troublesome, so I'll talk about it! In fact, the question can be done!

Question 1 Knowing that sodium ion grams, that is, let 10 sodium carbonate xmol sodium bicarbonate ymol, you can get the relation x y (106 180) x 84y x y can be found.

Finally, after burning, all the water in the sodium carbonate in xmol 10 water is consumed, and after the ymol sodium bicarbonate is burned, the water liquid Chang and CO2 all run away, and then it is not the same as doing!

The second question is simple! It is a set of formulas Simply put, knowing the concentration and volume of potassium permanganate, you can find the amount of its substance, and the amount of H2C2O4 can be found according to the equation shown by Tihao Zheng According to Cac2O4 H2SO4 CaSO4 H2C2O4 You can find the Ca ion concentration Then see if it is within the range given by the question! That's it.

Oh mom, there are too many questions!! Help me downstairs.。。。 I'm tired of typing so many words... The landlord, I'm flashing! Give or not give points as you like!

The sodium-containing mass ratio of sodium bicarbonate to sodium carbonate is 1; 2. You can find the mass of sodium contained in sodium bicarbonate, and you can find the mass of sodium carbonate according to the mass fraction of sodium carbonate.

According to the prompts, potassium permanganate was used to find the molar mass of H2C2O4, and the molar mass of H2C2O4 was the same as that of Cac2O4

The molar mass is 1:1 and is 10 milliliters, so you can find the concentration of calcium ions, according to the molar mass of potassium iodide, you will know the chlorine, and then you will know the sodium hypochlorite according to the public talk that people give you the age of resistance.

Alas. That's all there is to it.

You have too many questions.

I have time to watch.

The metal is all dissolved.

Indicates that the metal is completely reactive.

fe+h2so4=feso4+h2↑

The amount of the book and bond substance of the gas is the same as the amount of the substance of iron.

By data there is a shed latte in the iron filings.

Its quality is: 56×

The mass of iron is state.

I don't know what you're asking? Is it to be explained?

From the reaction equation 3 no2 + h2o = 2 hno3 + no, it can be seen that no2 reacts with water to form no, and the amount of its substance is the original 1 3, and according to Avogadro's law, the volume of the gas is also the original 1 3, so the water surface rises to about 2 3 of the volume.

If O2 is continued, then there is 2 no + o2 = 2 no2 ; 3 NO2 + H2O = 2 HNO3 + NO, reddish-brown again, and the liquid level rises again.

If you ask what is the volume of oxygen that is finally introduced, and the water fills the tube, the answer is 1 4 of the volume of the tube

The brief explanation is as follows: 3 no2 + h2o = 2 hno3 + no --1).

2 no + o2 = 2 no2 --2）

1) *2 + (2) * 3 (add both sides of the equation to simplify) to get (3).

4 no2 + o2 + 2 h2o = 4 hno3---3）

From (3), it can be seen that when the ratio of the amounts of substances of No2 and O2 is 4:1, it happens to be a complete reaction.

Hope it helps!

3no2+h2o→2hno3+no

2no+o2→2no2

Infinite circulation, only nitric acid is left at the end, and there is no gas residue in the test tube.

1）3o2===2o3

Let the imitation slag reed have 1molo2, if 30% of the oxygen is converted to ozone in the above reaction, yes, the average molar mass of the gas mixture is 32 g Liangshen mol2)3O2===2O3 V

x x = 3 l ozone 3 l

3) n=Let O3 be ymol and O2 be Zmol

y+z=48y+32z= y=

The volume fraction of ozone in the mixture is .

The last backup question O2 and O3 are all absorbed by copper, and the difference method cannot be used.

（1）kio3 + 5ki + 3h2so4 = 3k2so4 + 3i2 + 3h2o

2）i2 + so32- +h2o = so42- +2h+ +2i-

3）i2 + 2s2o32- = 2i- +s4o62-

x solves: x =

kio3 + 5ki + 3h2so4 = 3k2so4 + 3i2 + 3h2o

1 3y solution: y =

The solution happens to be blue and disappears. (But if the answer is blue, there is no step to the back titration).

×127g/mol = =

W 1000kg = 420 W (mg kg), unqualified.

However, I think you must be missing one step in this question, it is very likely to take out a certain volume of solution after dilution, or add more sodium thiosulfate and then use the I2 solution to titrate, resulting in inconsistent calculation results.

i kio3 3i2 and i2 2s2o32-then i 6s2o3-

x 2*x==127* 2* g

That is, there is g iodine in WG table salt.

One kilogram has *1000 W g

i.e. 420 mg kg

1 Analysis: The mass of Fe is found from the mass of hydrogen, then the mass of Cu is the classmate, is the data of this question correct? Or am I dizzy and don't have the right answer? ）

2 Analysis: The precipitate is mg(OH)2, just is, then the amount of magnesium chloride is conserved by magnesium), so choose b

3. The mixture of sodium carbonate and sodium bicarbonate is put into hydrochloric acid for complete reaction, and the nitric acid solution is just consumed.

1) Write the chemical equation for the reaction.

Na2CO3 + 2HCl = 2NaCl + H2O + CO2 (gas).

NaHCO3 + HCl = NaCl + H2O + CO2 (gas).

2) Calculate the mass fraction of sodium carbonate in the mixture.

Is it hydrochloric acid or nitric acid?

Let the amount of sodium carbonate be x and the amount of sodium bicarbonate be y

106x+84y=

63 (2x + y) = 50 * nitric acid).

This data should be nitric acid, so it should be possible to solve x y and then calculate it with the above two equations. I don't need to count the specific data!

Quality score: 106x is sufficient.

4. 100g of copper hydroxide and copper mixture were fully heated and burned in air, and it was found that the solid mass was still 100g after burning. If 100g of the mixture is put into a sufficient amount of dilute sulfuric acid, it is filtered after full reaction, and the mass of the solid is wg.

1) Write the chemical equation for the reaction when burning.

2cu+o2=2cuo

Cu(OH)2 = (heating) CuO+H2O

2) Find the value of w.

The mass of the solid is the mass of the undissolved copper.

Let the amount of copper in the mixture be x and the amount of copper hydroxide y y

64x+98y=100

80*（x+y）=100

Calculate x=? Then w=64x

A bit lazy, the calculation part is omitted!

1.Let the Fe mass in the original mixture be x grams.

fe+h2so4=feso4+h2↑

56 2xg

56/xg=2/

x=m（cu）=

No options...

2.Let the mass of MgCl2 be Xg

mgcl2+2naoh=mg(oh)2+2nacl95 58x

95/x=58/

x=mgcl2%=

na2co3+2hcl==2nacl+h2o+co2↑nahco3+hcl==nacl+h2o+co2↑（2）50g*

na2co3+2hcl==2nacl+h2o+co2↑106 73

x a=73x/106nahco3+hcl==nacl+h2o+co2↑84

x=The data should be incorrect.

4.(1) Cu(OH)2= =CuO+H2O, the masses of copper hydroxide and copper in the original mixture are x and y, respectively, and the mass of water generated by copper hydroxide after thermal decomposition is m, so according to the title, it can be seen that the mass of oxygen participating in the reaction is also m

cu(oh)2=△=cuo+h2o

98 18x m98:18=x:m

x=49m/9

2cu + o2= △= 2cuo

y m128:32=y:m

y=4mx+y=49m/9+4m=100g

m=w=y=4m=4*

I'll write it down on paper and show you.

1.grams (no correct answer).

2. b3.（1）nahco3+ hno3 == nano3+ h2o+ co2

na2co3+ 2hno3 == 2nano3 + h2o +co2（2） *100%==

3) 20 grams.

4. （1） 2cu + o2 == 2cuo cu（oh）2 == cuo + h2o

2) grams.

I'll make up the detailed answer before seven o'clock.

3) 3Cu + O3 = = = 3Cuo, 2Cu + O2 = 2Cuo, the oxidation of ozone is stronger than that of oxygen socks, and it can also react with copper, which is the total mass of ozone and oxygen.

Which do you want to overdose first! It depends on the situation! You can't just pull it with a one-step difference method!!