In: Chemistry
The vapor pressure of solid benzene is 299 Pa at -30ºC and 3270 Pa at 0ºC. The vapor pressure of liquid benzene is 6170 Pa at 10ºC, and 15,800 Pa at 30ºC. (a) Calculate the triple point of benzene (temperature and pressure at which solid, liquid, and vapor all coexist). This is obtained by using the Clausius-Clapeyron equation first to determine ∆vapH for the solid and the liquid, and then to give equations for the curves defining the solid-vapor equilibrium and the liquidvapor equilibrium, and solving both the latter equations simultaneously. (b) Calculate the enthalpy of fusion at the triple point, ∆fusH = Hliq – Hsol.