Photochemical smog is a resultant of the reaction among

1. NO2, 03 and peroxyacetyl nitrate in the presence of sunlight
2. CO, 02 and peroxyacetyl nitrate in the presence of sunlight
3. CO, CO2 and N02 at low temperature
4. High concentration of N02, O3 and CO in the evening

Explanation

Option (a) is correct

• Photochemical smog is also known as summer smog or Los Angeles smog.
  It occurs most prominently in urban areas with high vehicular emissions.
• It forms when nitrogen oxides and volatile organic compounds react together in the presence of sunlight to form ozone (a secondary pollutant).
• The resulting smog causes a light brownish colouration of the atmosphere, reduced visibility, plant damage, irritation of the eyes, and respiratory distress.

Answer: (a) NO2, 03 and peroxyacetyl nitrate in the presence of sunlight; Difficulty Level: Easy