Bailey, Clark, Ferris, Krause and Strong, “Chemistry of the Environment,” second edition (San Diego: Academic Press) 2002.

Photochemical Smog:

[O3] depends on the ratio [NO]

][NO2

and on [VOC]

Generally, [VOC] [O3]

BUT

If VOC are in excess, changing [VOC]

has little effect; [NOx] [O3]

If [VOC] is low relative to [NOx], a situation

can occur where [NOx] [O3]

Why? VOC, NOx compete for OH

[NOx] more VOC reacts w/ OH [O3]