1. The problem statement, all variables and given/known data NO2 is a known air-pollutant resulting from the combustion of petroleum in vehicles. Suppose at 6:00 am, there are 0.920 ppm NO2 in a liter of air. Calculate the mass (in grams) of the NO2 present in a liter, assuming there are 2.46x10^22 molecules of air in 1.00 L. (1 ppm = 10-6) 2. Relevant equations particle to mole to mass conversion PV=nRT(maybe) 3. The attempt at a solution I have no idea how to do this. The only thing I could think of is changing the number of molecules to some mass by changing it to moles than use the molar mass of NO2 to get mass I would appreciate any help on this. Thanks.