In the reaction 4Al + 3O_2 → 2Al_2O_3, how many moles of O_2 are consumed when 8 moles of Al are reacted?

• A. 12 moles
• B. 6 moles
• C. 8 moles
• D. 4 moles

Answer: (B)

Verified step by step guidance

1. Identify the balanced chemical equation: \$4Al + 3O_2 \rightarrow 2Al_2O_3$.
2. Determine the mole ratio between aluminum (Al) and oxygen gas (\(O_2\)) from the balanced equation. For every 4 moles of Al, 3 moles of \(O_2\) are consumed.
3. Set up a proportion to find the moles of \(O_2\) consumed when 8 moles of Al react: \(\frac{4\ \text{moles Al}}{3\ \text{moles } O_2} = \frac{8\ \text{moles Al}}{x\ \text{moles } O_2}\).
4. Solve the proportion for \(x\) (moles of \(O_2\)): \(x = \frac{8 \times 3}{4}\).
5. Interpret the result as the number of moles of \(O_2\) consumed when 8 moles of Al react.