 # Why do equal quality zinc powder and iron powder put into dilute sulfuric acid with equal mass and same solute mass fraction produce more hydrogen Why do equal quality zinc powder and iron powder add the same mass fraction of dilute sulfuric acid to produce more hydrogen

## Why do equal quality zinc powder and iron powder put into dilute sulfuric acid with equal mass and same solute mass fraction produce more hydrogen Why do equal quality zinc powder and iron powder add the same mass fraction of dilute sulfuric acid to produce more hydrogen

The molar mass of iron is less than that of zinc. The molar number of iron and zinc iron is greater than that of zinc. The hydrogen replaced by equal molar iron and zinc is equal. Therefore, when equal mass zinc powder and iron powder are put into the same mass fraction of dilute sulfuric acid, iron produces more hydrogen

### 3.8g of the mixture of zinc powder, aluminum powder, iron powder and magnesium powder reacts exactly with dilute sulfuric acid with a mass fraction of 25% solute. Evaporate the water of the reaction mixture to 11g of solid (excluding crystal water), and the mass of hydrogen generated in the reaction is () A. 0.15g B. 0.20g C. 0.30g D. 0.45g

According to the subject information, the mixture and sulfuric acid react exactly, so the sum of the mass of the mixture and pure sulfuric acid (H2SO4) is equal to the sum of the mass of the remaining solid and hydrogen. The mass of sulfate before and after the reaction = (11g - 3.8g) = 7.2g, then the mass of pure sulfuric acid = 7.2g ÷ 96
98 = 7.35g. Therefore, the mass of hydrogen = the mass of hydrogen element in sulfuric acid = 7.35g - 7.2g = 0.15g, so a

### Put 10g of the mixture of iron powder and copper powder into a beaker containing sufficient dilute sulfuric acid. After full reaction, the total mass of the material in the beaker is reduced by 0.1g compared with the total mass of the metal mixture and dilute sulfuric acid before reaction. Calculate the mass fraction of copper powder in the original mixture

The mass of generated hydrogen is 0.1g, and the mass of iron participating in the reaction is assumed to be x.fe + H2SO4  FeSO4 + H2 ↑ 56               2x          ...

### 14g of the mixture of iron powder and copper powder is put into 116.2 dilute hydrochloric acid and the reaction is just complete. At this time, the total mass of each substance in the beaker is 129G 14g of the mixture of iron powder and copper powder was put into 116.2 dilute hydrochloric acid and the reaction was just complete. At this time, the total mass of each substance in the beaker was 129 Put 14g of the mixture of iron powder and copper powder into 116.2 dilute sulfuric acid and react exactly. At this time, the total mass of each substance in the beaker is 129.8g. Find: 1. Mass fraction of iron powder in the original mixture; 2. The volume of concentrated sulfuric acid with a mass fraction of 36% (density of 1.19g / cm3) is required to prepare the dilute sulfuric acid used above; 3. Mass fraction of solute in the solution after reaction Please don't copy

The total mass before the reaction is 14 + 116.2g = 130.2g, the mass of the beaker after the reaction is 129.8g, and the mass before and after the reaction is reduced by 130.2-129.8 = 0.4g. Because copper is inactive and does not react with acid, there is only one reaction: Fe + 2H + = Fe2 + + H2, so 0.4g of hydrogen is generated, 11.2g of fe11, 19.8g of sulfuric acid, 1. Mass fraction of Fe = 5.6 /

### 14g of the mixture of iron powder and copper powder is put into 116.2g of dilute hydrochloric acid and the reaction is just complete. At this time, the total mass of each substance in the beaker is 129.8g 1. What is the mass of hydrogen produced? 2. Mass fraction of iron powder in the original mixture?

After dilute hydrochloric acid is added to iron powder and copper powder, iron reacts with hydrochloric acid to generate ferrous chloride and hydrogen. Copper does not react with hydrochloric acid. According to mass conservation, m (iron powder + copper powder) + m (hydrochloric acid) = m (salt solution + copper powder) + m (hydrogen), so m (hydrogen) = 14 + 114.2-129.8 = 0.4gfe + 2HCl = FeCl2 + h256 2

### 14g of the mixture of iron powder and copper powder is put into 116.2g dilute hydrochloric acid, and the reaction is just complete. At this time, the total mass of each substance in the beaker is 129.8g Q: The volume of concentrated hydrochloric acid (density 1.19g/cm3) with a mass fraction of 36% is required to prepare the dilute hydrochloric acid used above? Write out the process and analysis. Don't copy it

Let the mass of iron be x, the mass of FeCl2 generated be y, and the mass of hydrochloric acid solute consumed be Z
The mass of H2 is 14g + 116.2g-129.8g = 0.4g
Fe + 2HCl ＝ FeCl2 + H2↑
56 73 127 2
X Z Y 0.4g
X=11.2g
Y=25.4g
Z=14.6g
The volume of 36% concentrated hydrochloric acid used is:
14.6g÷36％÷1.19g／cm3=34.08mL
The mass fraction of solute in the solution obtained after reaction is:
25.4g÷(11.2g+116.2g－0.4g) × 100％=20.0％