Q. Pick out the correct statement?
A) $CO$ which is major pollutant resulting from the combustion of fuels in automobiles plays a major role in photochemical smog
B) Classical smog has an oxidising character while the photochemical smog is reducing in character
C) Photochemical smog occurs in day time whereas the classical smog occurs in early morning hours
D) During formation of smog the level of ozone in the atmosphere goes down
Explanation
(d)
During the formation of photochemical smog the level of ozone in the atmosphere goes down.
$NO + O_{3}\overset{\ \ hv\ \ \ \ }{\rightarrow}\ NO_{2} + O_{2}$
In the atmosphere the organic compounds rapidly react with $O_{3},NO_{2}$ to form other noxious photochemical products known as peroxyacyl nitrates (PANs) and acrolein.
Photochemical smog occurs in warm, dry and sunny climate, generally during the day time while classical smog occurs in cool humid climate, generally in the early morning hours of winter months.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.