**Question **# A rigid, closed vessel of volume V = 648 L is loaded with 112 mol of n-hexane, 155 mol of n-heptane and 14 mol of nitrogen. The vessel is maintained at constant temperature, T = 365 K. Calculate the pressure in the vessel and the composition of all phases present at equilibrium. State all assumptions in your calculations. An equimolar mixture of propane and butane is initially in the liquid phase at T = 240 K and P=10 bar. The liquid flows through an adiabatic throttling valve that reduces its pressure to P=0.8 bar, resulting in partial evaporation of the mixture. Calculate the temperature and vapor fraction of the mixed vapor + liquid stream exiting the throttling valve. State all assumptions in your calculations.