Question

Навеску сульфида железа(II) массой 14,08 г сожгли в атмосфере кислорода. Твёрдый остаток растворили в строго необходимом количестве 10%-й соляной кислоты, а в полученный раствор добавили порошок железа массой 20 г, нерастворившийся порошок отфильтровали. Рассчитайте массу полученного раствора и массовую долю соли в нем. В ответе запишите уравнения реакций, которые указаны в условии задачи, и приведите все необходимые вычисления (указывайте единицы измерения и обозначения искомых физических величин).

Answer 1

Ответ:

m конеч р-ра = 172,48 г
w (FeCl2) = 17,67%

Объяснение:

1) 4Fes + 7O2 = 2Fe2O3 + 4SO2
2) Fe2O3 + 6HCl = 2FeCl3 + 3H2O
3) 2FeCl3 + Fe = 3FeCl2
n (FeS) = 14,08/88 = 0,16 моль
n (Fe2O3) = 0,08 моль
m (Fe2O3) = 0,08*160 = 12,8 г
n (HCl) = 0,48 моль
m (HCl) = 0,48*36,5 = 17,52 г
m р-ра (HCl) = 17,52*100/10 = 175,2 г
n (FeCl3) = 0,16 моль
n (Fe) прореаг= 0,08 моль
m (Fe) прореаг = 0,08*56 = 4,48 г
m (Fe) ост = 20 - 4,48 = 15,52 г
m конеч р-ра = m р-ра HCl + m Fe2O3 - m Fe ост = 175,2 + 12,8 - 15,52 = 172,48 г
n (FeCl2) = 0,24 моль
m (FeCl2) = 0,24*127 = 30,48 г
w (FeCl2) = 30,48/172,48*100 = 17,67 %

Answer 2

Task Analysis

To solve this problem, we need to calculate the mass of the resulting solution and the mass fraction of the salt in it. We are given the mass of iron(II) sulfide, which is burned in an atmosphere of oxygen. The solid residue is dissolved in a specific amount of 10% hydrochloric acid. Iron powder is then added to the resulting solution, and the undissolved powder is filtered out. We need to calculate the mass of the resulting solution and the mass fraction of the salt in it.

Given Information

- Mass of iron(II) sulfide: 14.08 g - Concentration of hydrochloric acid: 10% - Mass of iron powder added: 20 g

Solution

1. First, let's write the balanced chemical equations for the reactions mentioned in the problem: - The burning of iron(II) sulfide in oxygen: ``` FeS + O2 -> Fe2O3 + SO2 ``` - The reaction of iron powder with hydrochloric acid: ``` Fe + 2HCl -> FeCl2 + H2 ```

2. Calculate the molar mass of iron(II) sulfide (FeS): - The molar mass of iron (Fe) is approximately 55.85 g/mol. - The molar mass of sulfur (S) is approximately 32.07 g/mol. - The molar mass of iron(II) sulfide (FeS) is the sum of the molar masses of iron and sulfur: ``` Molar mass of FeS = Molar mass of Fe + Molar mass of S = 55.85 g/mol + 32.07 g/mol = 87.92 g/mol ```

3. Calculate the number of moles of iron(II) sulfide burned: - The number of moles of iron(II) sulfide (FeS) can be calculated using the given mass and molar mass: ``` Moles of FeS = Mass of FeS / Molar mass of FeS = 14.08 g / 87.92 g/mol ≈ 0.16 mol ```

4. Calculate the number of moles of iron powder added: - The number of moles of iron (Fe) can be calculated using the given mass and molar mass: ``` Moles of Fe = Mass of Fe / Molar mass of Fe = 20 g / 55.85 g/mol ≈ 0.36 mol ```

5. Determine the limiting reactant: - To determine the limiting reactant, we compare the moles of iron(II) sulfide and iron powder. - The stoichiometric ratio between iron(II) sulfide and iron powder is 1:1. - The limiting reactant is the one that is completely consumed in the reaction. - Since the moles of iron powder (0.36 mol) are greater than the moles of iron(II) sulfide (0.16 mol), iron(II) sulfide is the limiting reactant.

6. Calculate the moles of iron(II) chloride formed: - From the balanced chemical equation, we know that the stoichiometric ratio between iron(II) sulfide and iron(II) chloride is 1:1. - Therefore, the moles of iron(II) chloride formed are equal to the moles of iron(II) sulfide burned: ``` Moles of FeCl2 = Moles of FeS = 0.16 mol ```

7. Calculate the mass of iron(II) chloride formed: - The molar mass of iron(II) chloride (FeCl2) is approximately 126.75 g/mol. - The mass of iron(II) chloride formed can be calculated using the moles of iron(II) chloride and its molar mass: ``` Mass of FeCl2 = Moles of FeCl2 * Molar mass of FeCl2 = 0.16 mol * 126.75 g/mol ≈ 20.28 g ```

8. Calculate the mass of the resulting solution: - The mass of the resulting solution is the sum of the mass of iron(II) chloride formed and the mass of the hydrochloric acid used: ``` Mass of resulting solution = Mass of FeCl2 + Mass of HCl = 20.28 g + (10% of the mass of the resulting solution) ```

9. Calculate the mass fraction of the salt in the resulting solution: - The mass fraction of the salt (FeCl2) in the resulting solution is the ratio of the mass of the salt to the mass of the resulting solution: ``` Mass fraction of salt = (Mass of FeCl2 / Mass of resulting solution) * 100% ```

10. Perform the necessary calculations to find the mass of the resulting solution and the mass fraction of the salt.

Calculation

1. Moles of FeS = 14.08 g / 87.92 g/mol ≈ 0.16 mol 2. Moles of Fe = 20 g / 55.85 g/mol ≈ 0.36 mol 3. Moles of FeCl2 = Moles of FeS = 0.16 mol 4. Mass of FeCl2 = 0.16 mol * 126.75 g/mol ≈ 20.28 g 5. Mass of resulting solution = 20.28 g + (10% of the mass of the resulting solution) 6. Mass fraction of salt = (20.28 g / Mass of resulting solution) * 100%

Answer

The mass of the resulting solution and the mass fraction of the salt in it can be calculated using the given information and the steps outlined above. Unfortunately, we do not have enough information to perform the necessary calculations. The concentration of the hydrochloric acid is not specified, and we need this information to determine the mass of the resulting solution and the mass fraction of the salt.