Latent heat is the heat that is needed to achieve a phase transfer. Each chemical species require different latent heat for phase transfer. Please make use of the vapor pressures (listed in the table below) as a function of temperature and of the saturated-liquid and saturated-vapor volumes of tetrafluoroethane, calculate the latent heat of vaporization at one of the following temperatures and compare the result with the latent heat of vaporization calculated from the enthalpy values given in the table.

(a) (5 pts) -30C; (b) (5 pts) 4C; (c) (5 pts) 70C.