Isoprene (C5H8) is a natural atmospheric component emitted by coniferous forests, and is responsible for the blue haze of the Great Smoky Mountains in the Southeastern US. It is quickly degraded in the atmosphere though reaction with OH• and O3 to form non volatile species which then form particles. These latter ones are responsible for the haze.
The rate constants are known
OH• + isoprene (C5H8) ? radical +H2O
kOH = 1x10 -10 molecule-1cm3s-1
O3 + isoprene (C5H8) ?product +H2O
kO3= 1.4x10-17 molecule-1cm3s-1
Under atmospheric conditions and at a typical isoprene concentration of
5.9 x1010 molecules/cm3, the rates of the reactions are found to be
(rOH) = 4.7x106 molecule-1cm3s-1
(rO3) = 2.0x106 molecule-1cm3s-1
What must the O3 and OH• concentrations have been?