Photochemical smog formation
Question
Photochemical smog is a resultant of the reaction among (a) NO_2, O_3 and peroxyacetyl nitrate in the presence of sunlight (b) CO, O_2 and peroxyacetyl nitrate in the presence of sunlight (c) CO, CO_2 and NO_2 at low temperature (d) high concentration of NO_2, O_3 and CO in the evening
Options
NO_2, O_3 and peroxyacetyl nitrate in the presence of sunlight
CO, O_2 and peroxyacetyl nitrate in the presence of sunlight
CO, CO_2 and NO_2 at low temperature
high concentration of NO_2, O_3 and CO in the evening
Explanation
Photochemical smog is formed by the reaction of nitrogen oxides (NOx), volatile organic compounds (VOCs), and oxygen in the presence of UV sunlight. The primary pollutants include nitrogen dioxide (NO₂), which reacts with sunlight to produce ozone (O₃). Peroxyacetyl nitrate (PAN) is one of the secondary pollutants produced in this reaction. This type of smog typically forms during daytime in sunny conditions and is characteristic of areas with high vehicular traffic and industrial emissions. Option (c) is incorrect as it requires low temperature, and option (d) is incorrect as photochemical smog requires sunlight, not evening conditions. > Photochemical smog = secondary pollutants from NOx + sunlight + oxidants = Ozone + PAN.
Question details
Year
2013
Paper
GS Paper 1
Question
Q49
Subject
Environment
Sub-topic
Air pollution and smog
Type
Factual single
Difficulty
Medium
Nature
Static
Source hint
NCERT Chemistry - Air pollution
See all questions on Air pollution and smog
Browse every tagged question across all years