A worker, performing repairs inside a large air duct, spills a gallon of contact cement, which uses toluene as a solvent. The glue spreads out to an area of 4000 cm2. The vapor pressure of toluene in a closed headspace over the glue would be 10^-2 atm (less than for pure toluene, because toluene is part of a mixture). The air duct is 1.5 m high by 1 m wide, and a blower is creating a 1.2 m/sec airflow past the spill.

a. What concentration of toluene (mol/m3) do you expect to find in the air far downstream of the glue spill? b. A coworker turns up the blower, increasing air velocity to 2 m/sec to ventilate the duct more rapidly. What is the steady-state downstream toluene concentration now? c. The worker who spilled the glue covers it with kitty litter to a depth of 2 cm. Diffusion through the litter layer (for which you may use an effective value for Dmolecular of 0.01 cm2/sec) now controls the toluene evaporation rate (assume the glue does not soak up into the litter). Estimate by what factor the concentration downstream is decreased (assume the blower is turned back to its original setting).