In a polyurethane production chemical plant, a container of nitrobenzene leaked for a week before the damage was repaired. It was estimated that the evaporation rate (Qm) of the nitrobenzene was approximately 0.005g/min. That room had a ventilation rate (Qv) of 5.5 m3/min. a. (4 points) Calculate the concentration of nitrobenzene in the described chemical plant. b. ( 8 points) Were the workers who had a work shift of 10h exposed to nitrobenzene above its TLV-TWA of 1 ppm? Hint: remember that TLV-TWA is based on 8h, so you will have to consider the longer work shift. Assume normal temperature (25C) and pressure ( 1 bar). Nitrobenzene has a molecular weight of 123.1g/mol. Concentration (in ppm) can be calculated using the following equation: kCppm=QvPMwQmRT106 k : mixing factor (assume a value of 0.2 ) Qm : evaporation rate Qv: ventilation rate R : gas constant T : temperature Mw: molecular weight