Exercise 1 Pressure (a.u.) Temperature, To (constant) Bubble point line PA P1 1x Dew point line P2 2. P3 3 4 P4 Pa PS 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Mole fraction of A (x) The figure above is a P-composition diagram (at constant T) for a two-component mixture of ethane and heptane. Taking into account the relative magnitudes of their molar mass: (i) Which is more volatile, ethane or heptane? Explain your answer in one or two lines. (ii) Explain the process of depressurisation from P1 to P5, indicating for each point: the phase or phases in which the mixture is found an estimate of the compositions of the corresponding phases (in x,), indicating the calculations on the diagram.