Question

Образец природного минерала железа содержит Fe2O3 и примеси, массовая доля которых составляет 12%. Вычислите массу Fe2O3 в 250 г минерала и массу железа, которая может быть из него получена.

Answer 1

Ответ: 154 г

Объяснение:

Answer 2

Calculation of the Mass of Fe2O3 in the Mineral

To calculate the mass of Fe2O3 in the mineral, we need to use the given information that the mass fraction of impurities is 12% and the mineral has a mass of 250 grams.

The mass fraction of Fe2O3 can be calculated by subtracting the mass fraction of impurities from 100%. In this case, the mass fraction of Fe2O3 is 100% - 12% = 88%.

To find the mass of Fe2O3 in the mineral, we can multiply the mass of the mineral by the mass fraction of Fe2O3:

Mass of Fe2O3 = Mass of mineral × Mass fraction of Fe2O3

Substituting the given values:

Mass of Fe2O3 = 250 g × 88% = 220 g

Therefore, the mass of Fe2O3 in the mineral is 220 grams.

Calculation of the Mass of Iron Obtained from the Mineral

To calculate the mass of iron that can be obtained from the mineral, we need to consider the stoichiometry of the reaction between Fe2O3 and iron.

From the chemical formula of Fe2O3, we can see that there are 2 moles of iron (Fe) for every 1 mole of Fe2O3.

To calculate the molar mass of Fe2O3, we can use the atomic masses of iron (Fe) and oxygen (O) from the periodic table:

Molar mass of Fe2O3 = (2 × atomic mass of Fe) + (3 × atomic mass of O)

Using the atomic masses of Fe (55.845 g/mol) and O (15.999 g/mol):

Molar mass of Fe2O3 = (2 × 55.845 g/mol) + (3 × 15.999 g/mol) = 159.69 g/mol

Now, we can calculate the number of moles of Fe2O3 in the mineral by dividing the mass of Fe2O3 by its molar mass:

Number of moles of Fe2O3 = Mass of Fe2O3 / Molar mass of Fe2O3

Substituting the given values:

Number of moles of Fe2O3 = 220 g / 159.69 g/mol ≈ 1.378 mol

Since the stoichiometry of the reaction between Fe2O3 and iron is 2:1, we can conclude that the number of moles of iron (Fe) is half the number of moles of Fe2O3:

Number of moles of Fe = 1.378 mol / 2 ≈ 0.689 mol

To calculate the mass of iron, we can multiply the number of moles of Fe by its molar mass:

Mass of iron = Number of moles of Fe × Molar mass of Fe

Using the atomic mass of Fe (55.845 g/mol):

Mass of iron = 0.689 mol × 55.845 g/mol ≈ 38.46 g

Therefore, the mass of iron that can be obtained from the mineral is approximately 38.46 grams.