
Answer:
139.97 kPa
Explanation:
Assuming propane is an ideal gas
PV = nRT
n₁ ( number of mole f the first gas) of the 1 m³ rigid tank = P₁V₁ / RT₁ R gas constant = 8.314 J/mol
n₁ = 100kPa × 1 m³ / (8.314 J/mol × 300 K) = 0.0401 mol
n₂ = 0.5 m³ × 250 kPa / ( 8.314J/mol × 400 K) = 0.0376 mol where n₂ is the number of mole of the second gas
n total = n₁ + n₂ = 0.0401 mol + 0.0376 mol = 0.0777 mol
PV = nRT
P final pressure = nRT / V where V = V₁ + V₂ = 1 m³ + 0.5 m³ = 1.5 m³
P final pressure = 0.0777 mol × 8.314 J/mol × 325 K / 1.5 m³ = 139.97 kPa