Which of the following chemicals are responsible for production of photochemical smog?
مندرجہ ذیل میں سے کون سے کیمیکل فوٹو کیمیکل سموگ کی پیداوار کے لیے ذمہ دار ہیں؟
Answer: Nitrogen oxides and Hydrocarbons
Explanation
Photochemical smog:
- NOX is one of the primary causes of photochemical smog.
- Photochemical smog is a condition that develops when primary pollutants (such as oxides of nitrogen and volatile organic compounds) interact under the influence of sunlight to produce a mixture of secondary pollutants.
- Thus photochemical smog is mainly composed of oxides of nitrogen, volatile organic compounds (primary pollutants), ozone, and peroxyacetyl nitrate (PAN) (secondary pollutants).
Note:
It depends on primary pollutants as well as the formation of secondary pollutants.
Primary pollutants include
- Oxides of nitrogen, particularly nitric oxide (NO) and nitrogen dioxide (NO2)
- Volatile organic compounds.
Secondary pollutants include
- Peroxyl-acyl nitrates (PAN)
- Tropospheric ozone
- Aldehydes
An important secondary pollutant for photochemical smog is ozone, which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight.
