1. Using the liquid-vapor equilibrium diagram of an oxygen-nitrogen mixture, determine the composition of each phase at 84 K and 100 kPa.
2. Using the liquid-vapor equilibrium diagram of an oxygen-nitrogen mixture at 100 kPa, determine the temperature at which the composition of the vapor phase is 79 percent N2 and 21 percent O2.
3. An oxygen-nitrogen mixture consists of 30 kg of oxygen and 40 kg of nitrogen. This mixture is cooled to 84 K at 0.1 MPa pressure. Determine the mass of the oxygen in the liquid and gaseous phase.