Question

M(Fe(OH3)2=30,9 г m(Fe2O3)-?

Answer 1

Дано

m(Fe(OH)3) = 30.9 г

Решение

n(Fe(OH)3) = m(Fe(OH)3) / M(Fe(OH)3) = 30.9 / (56 + 3 * 16 + 3 * 1) = 30.9 / 107 = 0.29 моль

2Fe(OH)3 = Fe2O3 + 3H2O

n(Fe2O3) = 0.5n(Fe(OH)3) = 0.5 * 0.29 = 0.145 моль

m(Fe2O3) = n(Fe2O3)M(Fe2O3) = 0.145 * (2 * 56 + 3 * 16) = 0.145 * 160 = 23.2 г

Ответ: 23.2 г

Answer 2

To determine the mass of Fe2O3 (iron(III) oxide), we need to use the molar mass of Fe(OH)3 and apply stoichiometry.

The molar mass of Fe(OH)3 is: Fe: 55.85 g/mol O: 16.00 g/mol (three oxygen atoms in the formula) H: 1.01 g/mol (three hydrogen atoms in the formula)

Adding these together: Fe: 55.85 g/mol O: 48.00 g/mol (16.00 g/mol * 3) H: 3.03 g/mol (1.01 g/mol * 3)

Total molar mass of Fe(OH)3: 55.85 g/mol + 48.00 g/mol + 3.03 g/mol = 106.88 g/mol

Given that the mass of Fe(OH)3 is 30.9 g, we can use the molar mass to find the number of moles of Fe(OH)3:

moles of Fe(OH)3 = mass / molar mass moles of Fe(OH)3 = 30.9 g / 106.88 g/mol ≈ 0.2895 mol

According to the balanced chemical equation, the molar ratio between Fe(OH)3 and Fe2O3 is 2:1. Therefore, 0.2895 mol of Fe(OH)3 will produce half that amount of Fe2O3:

moles of Fe2O3 = moles of Fe(OH)3 / 2 moles of Fe2O3 = 0.2895 mol / 2 = 0.1448 mol

Finally, we can calculate the mass of Fe2O3 using its molar mass:

m(Fe2O3) = moles of Fe2O3 * molar mass of Fe2O3 m(Fe2O3) = 0.1448 mol * (2 * 55.85 g/mol + 3 * 16.00 g/mol) m(Fe2O3) ≈ 0.1448 mol * 159.7 g/mol ≈ 23.1 g

Therefore, the mass of Fe2O3 is approximately 23.1 grams.