5) Consider a substance that undergoes a phase transition at temperature T, = 300K and pressure P, = 5bar. The variation of Gibbs free energy per mole G with pressure for constant temperature T = T, in the vicinity of the phase transition is shown below. 10 600 500 6- 5- 400 300 200 3- 100 P3o 200 250 300 T(KI 400 450 350 PIbar) (Left) Variation of Gibbs free energy with pressure in the vicinity of a first-order phase transition at T, = 300K (solid line). The dashed line indicates the location of the phase transition. (Right) Phase boundary in the T-P plane (solid line). The dashed lines indicate the location of the reference point T,, Po- [Ibar = 10 Pa] From the figures above, estimate the difference in volume AV between the two phases a, (per mole of substance). (Hint: dG = V dP – SdT may be useful) From the result of (a) and from Figure 2, estimate the entropy difference AS between the two phases, and from this compute the latent heat of transition L (both per mole of substance). (Hint: L = TAS may be usefule)

5) Consider a substance that undergoes a phase transition at temperature T, = 300K and pressure P, = 5bar. The variation of Gibbs free energy per mole G with pressure for constant temperature T = T, in the vicinity of the phase transition is shown below. 10 600 500 6- 5- 400 300 200 3- 100 P3o 200 250 300 T(KI 400 450 350 PIbar) (Left) Variation of Gibbs free energy with pressure in the vicinity of a first-order phase transition at T, = 300K (solid line). The dashed line indicates the location of the phase transition. (Right) Phase boundary in the T-P plane (solid line). The dashed lines indicate the location of the reference point T,, Po- [Ibar = 10 Pa] From the figures above, estimate the difference in volume AV between the two phases a, (per mole of substance). (Hint: dG = V dP – SdT may be useful) From the result of (a) and from Figure 2, estimate the entropy difference AS between the two phases, and from this compute the latent heat of transition L (both per mole of substance). (Hint: L = TAS may be usefule)