Aliquid mixture of benzene and toluene containing 50.0 wt% benzene at 100.0 °c and pressure p0 atm is fed at a rate of 32.5 m3/h into a heated flash tank maintained at a pressure ptank < < p0. when the feed is exposed to the reduced pressure in this unit, a portion of it evaporates. the liquid and vapor product streams are in equilibrium at 75.0 °c and ptank. the liquid product contains 43.9 mole% benzene. when carrying out the requested calculations, assume volume additivity of liquid benzene and toluene, use raoult's law and the antoine equation where necessary, and negelect the effect of pressure on enthalpy.

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?