Acertain volatile substance evaporates from an open container into a room of volume 1000 ft'. the evaporation rate is determined to be 200 mg/min. if the air in the room is assumed to be well mixed, how many ft/min of fresh air must be supplied to ensure that the concentration of the volatile is maintained below its tlv of 100 ppm? the temperature is 77°f and the pressure is 1 atm. assume a volatile species molecular weight of 100. under most circumstances the air in the room cannot be assumed to be well mixed. how would poor mixing affect the quantity of air required?