Propane on reaction with Oxygen produces COâ‚‚ and water;
            C₃H₈ + 10 O₂   →  3 CO₂ + 4 H₂O
According to Balance equation,
             1 mole of C₂H₈ required  =  10 moles of O₂
Then,
       0.105 moles of C₂H₈ will require  =  X moles of O₂
Solving for X,
               X = ( 10 mol × 0.105 mol) ÷ 1 mol
               X = 1.05 mol of O₂
Result:
      1.05 mol of O₂ is required to consume 0.105 mol of C₂H₈ completely.