The estimated average concentration of NO2 in air in the United States in 2006 was 0.016 ppm.
(a) Calculate the partial pressure of the NO2 in a sample of this air when the atmospheric pressure is 755 torr (99.1 kPa).
(b) How many molecules of NO2 are present under these conditions at 20 °C in a room that measures 15 X 14 X 8 ft?