the diagram to the right shows a plot of temperature versus time for a sample that is allowed to cool and the temperature monitored. explain the observed temperature versus time history for a liquidsolid phase boundary as the sample undergoes a temperature change from point b to point e. [7 marks]
(b) define the term "normal boiling point". [3 marks]
(c) if two phases are in equilibrium at a given p and t the relationship between ïp that we exert and ït we must make to ensure that the two phases remain in equilibrium is given by: lnp2= lnp1 - ïvaph/r (1/t2 - 1/t1) + constant: the vapour pressure of pyridine is 50.0 kpa at 365.7 k and the normal boiling point is 388.4 k. what is the enthalpy of vaporisation of pyridine? [10 marks]
d) define the term "supercritical fluid"