Answer
See the answer below.
Work Step by Step
a) Since the pressure is less than the critical pressure and the temperature is far from the saturation curve, it's in the gas phase.
b) It's a mixture of solid and liquid (in that saturation curve).
c) $380\ mmHg=0.5\ atm$, so the gas-liquid saturation line at that pressure has a temperature of approximately -117$^{\circ}$.
d) From the phase-diagram it should be approximately 0.3 atm
e) The solid is generally the denser phase since the atoms are packed more closely than in liquids and with less freedom of movement.
