Answer:
12.6 g
Explanation:
Step 1: Write the balanced decomposition reaction
2 Fe₂O₃ ⇒ 4 Fe + 3 O₂
Step 2: Calculate the moles corresponding to 18.0 g of Fe₂O₃
The molar mass of Fe₂O₃ is 159.69 g/mol.
18.0 g × 1 mol/159.69 g = 0.113 mol
Step 3: Calculate the moles of Fe formed from 0.113 moles of Fe₂O₃
The molar ratio of Fe₂O₃ to Fe is 2:4. The moles of Fe formed are 4/2 × 0.113 mol = 0.226 mol
Step 4: Calculate the mass corresponding to 0.226 moles of Fe
The molar mass of Fe is 55.85 g/mol.
0.226 mol × 55.85 g/mol = 12.6 g