A bar with volume 500 m3 has 50 smokers in it, each smoking two cigarettes per hour. An individual cigarette emits, among other things, about 1.4 mg of formaldehyde (HCHO). Formaldehyde converts to carbon dioxide with a reaction rate coefficient k k = 0.40/h. Fresh air enters the bar at the rate of 1000 m3/h, and stale air leaves at the same rate.

a) Draw the mass balance diagram for this scenario.

b) Assuming complete mixing, estimate the steady-state concentration of formaldehyde in the air.

c) At 25oC and 1 atm of pressure, how does the result compare with the threshold for eye irritation of 0.05 ppmv?