Final answer:
The minimum number of moles of O₂ required for complete combustion of 1 mole of propane and 2 moles of butane is 18 moles. This is determined by using stoichiometry from the balanced chemical equations for the combustion of propane and butane.
Step-by-step explanation:
To calculate the minimum number of moles of O₂ required for the complete combustion of 1 mole of propane (C₃H₈) and 2 moles of butane (C₄H₁₀), we must first write the balanced chemical equations for the combustion reactions:
For propane:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
For butane:
C₄H₁₀ + ⅗O₂ → 4CO₂ + 5H₂O
As we can see from the balanced equations, we need 5 moles of oxygen for every mole of propane and 13/2 (6.5) moles of oxygen for every mole of butane for complete combustion.
Therefore, the total moles of O₂ required are:
For 1 mole of propane: 1 mole C₃H₈ × 5 moles O₂/mole C₃H₈ = 5 moles O₂
For 2 moles of butane: 2 moles C₄H₁₀ × 6.5 moles O₂/mole C₄H₁₀ = 13 moles O₂
Adding them together gives the minimum number of moles of O₂ required:
5 moles O₂ + 13 moles O₂ = 18 moles O₂