Answer:
final mole fraction of O₂ = 58.84% , CO₂ = 17.64% , H₂O = 23.52% .
final partial pressure of O₂ = 2.942 atm , CO₂ = 0.882 atm , H₂O = 1.176 atm .
Explanation:
Assuming that propane is present as a gas , and also that the combustion is complete:
C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O
then taking as a reference propane sample= 1 mol , then
initial moles of O₂ = 3* 5 moles = 15 moles
final moles of O₂= 3* 5 moles - 5 moles = 10 moles
final moles of CO₂ = 3 moles
final moles of H₂O = 4 moles
total number of moles = 10 + 3 + 4 = 17 moles
final mole fraction of O₂ = 10/17 = 0.5884 = 58.84%
final mole fraction of CO₂ = 3/17 = 0.1764 = 17.64%
final mole fraction of H₂O = 4/17 = 0.2352 = 23.52%
From Dalton's law for ideal gases , the partial pressure p=P*x then
final partial pressure of O₂ = 5 atm * 10/17 = 2.942 atm
final partial pressure of CO₂ = 5 atm * 3/17 = 0.882 atm
final partial pressure of H₂O = 5 atm * 1/17 = 1.176 atm
