Divide 24 out of 36 by 6（

Divide 24 out of 36 by 6（

"Divide 24 out of 36 by 6. To keep the size constant, the denominator should be (divided by 6)"
Or "divide 24 out of 36 by 6. To keep the size constant, the denominator should be (minus 30)"

If you divide the denominator of 1624 by 8, how can the numerator change so that the size of the fraction remains unchanged? What is the score after the change?

Dividing the denominator of 1624 by 8 is equivalent to reducing the denominator by 8 times, and the numerator should also be reduced by 8 times to keep the size of the fraction unchanged; the changed fraction is 1624 = 16 △ 824 △ 8 = 23

How many tons of magnetite with fe3o490% is needed to smelt 2000t pig iron with 3% impurity?

The mass of iron in pig iron is 2000t × (1-3%) = 1940t. Suppose that the mass of Fe3O4 is x.4co + Fe3O4 & nbsp; high temperature & nbsp; & nbsp; 3Fe + 4co2 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 1940t232168 = x1940t, X ≈ 2679.05t, the quality of magnetite required is 2679.05t △ 90% ≈ 2976.72t A: magnetite required is 2976.72t

A chemical team needs to determine the content of iron in scrap iron. Take 15g scrap iron and add it into enough dilute hydrochloric acid. After complete reflection, 0.45g hydrogen is obtained, and ferrous sulfate is generated (other impurities do not react with dilute sulfuric acid). Calculate the mass fraction of iron in scrap iron
It's better to work it out before five in the afternoon

Let the mass of iron in the reaction be X
Fe+H2SO4=FeSO4+H2↑
56 2
x 0.45g
56：x=2:0.45
x=12.6g
So the mass fraction of iron = 12.6g/15g * 100% = 84%
A: the mass fraction of iron in scrap iron is 84%

1. Experimental data
Before reaction: mass of beaker and dilute hydrochloric acid -- mass of 150 g limestone sample -- 12 g
After reaction: mass of beaker and mixture -- 157.6 G
Please calculate: (1) what is the mass of carbon dioxide generated after the reaction?
(2) What is the mass fraction of calcium carbonate in the limestone sample?

The reduced mass of reaction is the mass of CO2, which is 150 + 12-157.6 = 4.4g
Let the mass of calcium carbonate in the limestone sample be X
CaCO3 = high temperature = CaO + CO2 ↑
100 44
x 4.4g
100/x=44/4.4
x=10g
Mass fraction of calcium carbonate = 10 / 12 * 100% = 83.3%
A: (1) the mass of carbon dioxide generated after the reaction is 4.4g
(2) The mass fraction of calcium carbonate in the limestone sample is 83.3%

A piece of zinc copper alloy was put into 74.2 g dilute sulfuric acid, and then completely reacted to produce 0.2 g hydrogen
(1) Calculate the solute mass fraction of dilute sulfuric acid
(2) Calculate the mass fraction of solute in the solution after reaction
(3) There are 20 grams of 98% concentrated sulfuric acid in the laboratory. How many grams of water are needed to prepare this kind of dilute sulfuric acid?

Zn + H2SO4 = ZnSO4 + h26598 161 2 z = 6.5g x = 9.8g y = 16.1g 0.2g solute content of dilute sulfuric acid used = = 9.8g △ 74.2g × 100% = solute content of solution obtained after reaction = 16.1g △ 74.2g + 6.5g-0.2

Soda ash (Na2CO3) prepared by Hou's method often contains a small amount of sodium chloride. Dissolve 10g of soda ash containing sodium chloride in 102.32g dilute hydrochloric acid, just complete reaction, and collect 3.52G of gas (assuming that all the generated gases escape)? (2) The mass fraction of solute in the unsaturated solution obtained after reaction

Let the mass of sodium carbonate be x, the mass of sodium chloride be y, Na2CO3 + 2HCl  2nacl + H2O + CO2 , & nbsp; 106 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 117 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 44 & nbsp; X & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp

How much is 1 / 18 + 1 / 5

What is 1 in 18 + 1 in 5?
1/18+1/5
=5/90+18/90
=23/90
This is my conclusion after meditation,
If not, please ask, I will try my best to help you solve it~
If you are not satisfied, please understand~

What is 1.2 △ 18

1.2 △ 18 equals 12 / 180 = 2 / 30 = 1 / 15
If you don't understand, please ask. If you are satisfied, please adopt

What is one plus one plus 18?

It's twenty