What mass of propane is necessary to react with the amount of oxygen in the chemical formula C3H8 + 5O2 → 3CO2 + 4H2O

C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

n (O₂) = 1.407 mol

M (C₃H₈) = 44.1 g/mol

m (C₃H₈) / M (C₃H₈) = n (O₂) / 5

m (C₃H₈) = M (C₃H₈) n (O₂) / 5

m (C₃H₈) = 44.1*1.407/5=12.410 g

the mass of propane is 12.410 g