Photochemical smog is a resultant of the reaction among
A
NO2, O3 and peroxyacetyl nitrate in the presence of sunlight
B
CO, O2 and peroxyacetyl nitrate in the presence of sunlight
C
CO, CO2 and NO2 at low temperature
D
high concentration of NO2, O3 and CO in the evening
Correct Answer: Option A
Explanation
1. Photochemical smog, also known as Los Angeles smog, is a type of air pollution produced when ultraviolet light from the sun reacts with nitrogen oxides (NOx) in the atmosphere.
2. This reaction involves primary pollutants like nitrogen oxides (particularly NO2) and volatile organic compounds (VOCs) emitted from sources like vehicles and industrial processes.
3. In the presence of sunlight, these primary pollutants undergo complex photochemical reactions to form secondary pollutants.
4. The key secondary pollutants characteristic of photochemical smog include ground-level Ozone (O3) and peroxyacetyl nitrate (PAN).
5. Option (A) correctly identifies the key components (NO2, O3, peroxyacetyl nitrate) and the essential condition (presence of sunlight) for the formation of photochemical smog.
6. Options (B), (C), and (D) include incorrect components (CO, CO2, O2 in these contexts) or incorrect conditions (low temperature, evening).