Answer:
166 g
Explanation:
Step 1: Write the reaction for the obtaining of Fe from magnetite
Fe₃O₄ ⇒ 3 Fe + 2 O₂
Step 2: Calculate the moles corresponding to 120 g of Fe
The molar mass of Fe is 55.85 g/mol.
120 g × (1 mol/55.85 g) = 2.15 mol
Step 3: Calculate the moles of Fe₃O₄ required to produce 2.15 moles of Fe
The molar ratio of Fe₃O₄ to Fe is 1:3. The moles of Fe₃O₄ required are 1/3 × 2.15 mol = 0.717 mol
Step 4: Calculate the mass corresponding to 0.717 moles of Fe₃O₄
The molar mass of Fe₃O₄ is 231.53 g/mol.
0.717 mol × 231.53 g/mol = 166 g