8. A power plant located in a valley is the main source of NO2. The valley is approximately square, 25 km × 25 km. Meteorologists predict that an incoming high-pressure

weather system will create an inversion that will prevent atmospheric mixing above a height of200 m. The volume below 200 m can be considered well-mixed. Winds are expected to blow clean air in from the west at 4 m/s during the inversion period. Photochemical reactions in the atmosphere degrade NO2 with a first-order rate constant,k, of 8x 105 s1. During normal operation, the power plant burns 130 kg/s of the algae, which has a nitrogen content of 6.5% by mass. All of the nitrogen in the biomass is converted to NO2upon combustion. This "fuel NO2" represents 2/3 of the total NO2 emissions from the power plant. The power plant plans to switch to a fuel with 1.3% nitrogen during the inversion period.What steady-state concentration of NO2 to you expect to observe in the valley during the inversion? Give your answer in ug/m3.