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

96.66 g of Fe₃O₄

Step-by-step 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).(111.68gFe)/(159.69gFe_(2)O_(3)) .(231.54gFe_(3)O_(4))/(167.52gFe) =96.66gFe_(3)O_(4)`