Final answer:
To react completely with 4.0 mol of C₇H₁₆, 44.0 moles of O₂ are needed based on the stoichiometry of the balanced combustion reaction.
Step-by-step explanation:
To determine how many moles of O₂ are required to react completely with 4.0 mol of C₇H₁₆, we need to establish the balanced chemical equation for the combustion of heptane (C₇H₁₆). The general equation for the complete combustion of a hydrocarbon like C₇H₁₆ is:
C₇H₁₆ + O₂ → CO₂ + H₂O
To balance the combustion reaction for heptane, we need sufficient oxygen molecules to produce carbon dioxide and water. The balanced equation is:
C₇H₁₆ + 11O₂ → 7CO₂ + 8H₂O
From the balanced equation, we can see that 1 mole of heptane reacts with 11 moles of oxygen. Therefore, 44.0 moles of O₂ are needed to completely react with 4.0 mol of C₇H₁₆ because if 1 mole of C₇H₁₆ requires 11 moles of O₂, 4 moles will need 4 times as much.