4. (20 points) une is evaporating from a beaker at a constant temperature of 420 C and a pressure of at The peaker is 25.0 cm in height and is initially filled with toluene to a depth of 15.0 cm Pure ait is blowing across the top of the beaker. The diffusivity of toluene in air is Du = 0.086 cm/s at 25.9 C. The vapor pressure of toluene at 42.0 *C is P= 64.2 mmHg. Determine the initial flux of toluene, N., in kgmol/ms when the evaporation process starts AND the final flux, Nas, in kgmol/m s' when the last of the toluene evaporates