The following expressions are available for the saturation pressures of a substance A: Liquid-vapor: Solid-vapor: In(Psat) = 47.83 7381 T 5.18 In(T) A In(Psat) = 34.16 - 8240 T - 2.51 In(T) Where Pat is in atm and T is in K. (a) Calculate the value of the triple point temperature TT and pressure PT of substance A fusion (TT). (b) Determine the heat of fusion of substance A at its triple point temperature, AhA