Answer:
1296 moles of Fe
Explanation:
To know how many iron can be recovered you need to know the moles of Fe₃O₄ in 100,0kg (100,0x10³g) using molar mass of Fe₃O₄ (231,533 g/mol):
Moles of Fe₃O₄:
100,0x10³g × (1mol / 231,533g) = <em><u>431,9 moles of Fe₃O₄</u></em>
As molecular formula of Fe₃O₄ contains 3 atoms of Fe, you will have 3 moles of Fe per mole of Fe₃O₄. Thus, moles of Fe are:
431,9 moles of Fe₃O₄ × (3 moles Fe / 1 mole of Fe₃O₄) = <em>1296 moles of Fe</em>
I hope it hepls!