A sample of liquid X, is introduced into an evacuated chamber with a movable piston. The pressure is measured as a function of the volume of the container while the temperature is maintained at $50°C,$ and the graph below is obtained. Choose the correct group of statements.
I) At volumes below 60 mL, X is only present in the liquid phase.
II) At volumes above 60 mL, X is only present in the gaseous phase.
III) If the process were repeated at 60 °C, the point at which the pressure begins to decrease would shift to higher volume.
IV) If more ‘X’ were added to the container, the pressure at V = 20 mL would increase