Definition of Dobson unit
1 Dobson Unit (DU) is defined to be 0.01 mm thickness at standard temperature and pressure (STP)
How many molecules are in a column with area 1 cm
2and containing 300 DU of ozone?
k is Boltzmann’s constant = 1.3806505(24) × 10−23 J K−1 T is 273 K
P=1 atm=1013.25 mbar=101325 Pa A=1cm2=10-4m2
h=height of ozone column at STP=3 mm