Iron is an indispensable trace element for human beings. Normal people should supplement about 14 mg of iron every day, most of which come from food. If all of them take tablets containing FeSO4 · 7H2O to supplement iron, they need to take tablets containing FeSO4 · 7H2O every day______ The content of Fe2 + in a ferrous sulfate tablet on the market is 16.0%. The Fe2 + in the tablet is easy to deteriorate in the air, and the state stipulates that the tablet can not be taken if the Fe2 + deteriorates more than 10.0%. In order to test whether the ferrous sulfate tablet sold in a drugstore is ineffective, 10.0g of the tablet is determined to contain 1.52g of Fe2 +?

Iron is an indispensable trace element for human beings. Normal people should supplement about 14 mg of iron every day, most of which come from food. If all of them take tablets containing FeSO4 · 7H2O to supplement iron, they need to take tablets containing FeSO4 · 7H2O every day______ The content of Fe2 + in a ferrous sulfate tablet on the market is 16.0%. The Fe2 + in the tablet is easy to deteriorate in the air, and the state stipulates that the tablet can not be taken if the Fe2 + deteriorates more than 10.0%. In order to test whether the ferrous sulfate tablet sold in a drugstore is ineffective, 10.0g of the tablet is determined to contain 1.52g of Fe2 +?

(1) Normal people should supplement about 14mg of iron every day, then they need to take about 14mg of FeSO4 · 7H2O every day, so the answer is: 69.5; (2) the amount of Fe2 + deterioration in 10.0g ferrous sulfate tablets containing Fe2 + 1.52g = 10.0g × 16.0% − 1.52g × 10.0g × 16.0% × 100% = 5

In the oxide of a metal element R, the mass ratio of R to oxygen is 9:8, and the relative atomic mass of R is 27
A. ROB. R2OC. R3O4D. R2O3

In the oxide of a metal element R, the mass ratio of R to oxygen is 9:8, and the relative atomic mass of R is 27. Suppose the chemical formula of the oxide is rxoy, then 27x: 16y = 9:8, X: y = 2:3, so the chemical formula of the oxide is r2o3

Hydrogen peroxide solution, commonly known as hydrogen peroxide, will decompose slowly during storage. The chemical equation is: 2h2o2 = = 2H2O + O2 ↑. There is a bottle of hydrogen peroxide that has not been used and has been stored for a long time. The commodity label on the bottle provides the following information:
1. The mass fraction of H2O2 is 30%
2. The mass of internal solution is 1000g
The mass fraction of H2O2 is only 10%
(1) If this bottle of hydrogen peroxide is used to prepare 1500g of medical hydrogen peroxide with 3% H2O2 mass fraction, what is the mass of hydrogen peroxide needed?
(2) . calculate the mass of hydrogen peroxide decomposed in this bottle of dioxygen water

(1) If this bottle of hydrogen peroxide is used to prepare 1500g of medical hydrogen peroxide with 3% H2O2 mass fraction, what is the mass of hydrogen peroxide needed?
When the mass fraction of H2O2 is 3%, the mass ratio of H2O2 is 1500 × 3% = 45g
Therefore, the mass fraction of hydrogen peroxide with 10% is needed: 45 △ 10% = 450 G
(2) . calculate the mass of hydrogen peroxide decomposed in this bottle of dioxygen water
The mass of original H2O2 is: 1000 × 30% = 300g
Let the mass of decomposed H2O2 be XG and the mass of generated O2 be YG
2H2O2==2H2O+O2↑
sixty-eight point three two
xg.yg
68/xg=32/yg
y=8x/17
So the total mass of the solution is: 1000-y = 1000-8x / 17
The mass of H2O2 is 300-x
Because the mass fraction of H2O2 is only 10%
So, (300-x) / (1000-8x / 17) = 10%
The solution is x = 210 G
Therefore, the mass of hydrogen peroxide decomposed in dioxygen water is 210g