Question

Calculate the weight of Fe3O4 in 100.0g Fe2O3.

Given: molar mass of Fe2O3 =159.69 g/mol Molar mass of Fe3O4 = 231.54 g/mol Hint: you need two conversion factors

Answer 1

Answer:

96.66 g of Fe₃O₄

Explanation:

In order to calculate the weight of Fe₃O₄ in 100.0 g of Fe₂O₃ we need elements in common between both substances, for instance, the mass of Fe in each one. We will use the molar mass of Fe = 55.84g/mol The conversion factors we need are:

• 159.69 g of Fe₂O₃ contain 2 × 55.84 = 111.68 g of Fe

• 231.54 g of Fe₃O₄ contain 3 × 55.84 = 167.52 g of Fe

Then, we can use proportions:

$100.0gFe_{2}O_{3}.\frac{111.68gFe}{159.69gFe_{2}O_{3}} .\frac{231.54gFe_{3}O_{4}}{167.52gFe} =96.66gFe_{3}O_{4}$