
Answer:
9.5 mol
Explanation:
Let's consider the unbalanced equation for the combustion of tetraethyl-lead (IV).
Pb(C₂H₅)₄ + O₂ ⇒ PbO + CO + H₂O
Pb atoms are balanced. We will balance C atoms by multiplying CO by 8.
Pb(C₂H₅)₄ + O₂ ⇒ PbO + 8 CO + H₂O
Then, we will balance H atoms by multiplying H₂O by 10.
Pb(C₂H₅)₄ + O₂ ⇒ PbO + 8 CO + 10 H₂O
Finally, we get the balanced equation by multiplying O₂ by 9.5.
Pb(C₂H₅)₄ + 9.5 O₂ ⇒ PbO + 8 CO + 10 H₂O
All in all, we need 9.5 moles of O₂ to burn 1 mole of Pb(C₂H₅)₄.