A mixture of methane and ethane has a density of 1.027 g/l at STP. Calculate the volume of oxygen required for the complete combustion of 10 liters of this mixture.
- 27.5 L
- 20.0 L
- 35.0 L
- 25.0 L
📝 Detailed explanation
Average molar mass M = 1.027 * 22.4 = 23 g/mol.Let x be the volume of methane (CH₄, M=16) and (10-x) be ethane (C₂H₆, M=30).
16x + 30(10-x) = 23 * 10.
16x + 300 - 30x = 230 => 14x = 70 => x = 5 L.
V(CH₄) = 5 L, V(C₂H₆) = 5 L.
CH₄ + 2O₂ → CO₂ + 2H₂O (Needs 2 * 5 = 10 L O₂).
C₂H₆ + 3.5O₂ → 2CO₂ + 3H₂O (Needs 3.5 * 5 = 17.5 L O₂).
Total O₂ = 10 + 17.5 = 27.5 L.