The pollutants which come directly in the air from sources are called primary pollutants. Primary pollutants are sometimes converted into secondary pollutants. Which of the following belongs to secondary air pollutants?
(i) CO         (ii) Hydrocarbon        (iii) Peroxyacetyl nitrate       (iv) NO

Answer: (iii)
Secondary pollutants are chemical species that are formed in the atmosphere through chemical reactions involving primary pollutants and other atmospheric constituents.
Examples of secondary pollutants include ozone (O3), sulfuric acid (H2SO4), and peroxyacetyl nitrate (PAN). Therefore, the correct answer to the question is (iii) Peroxyacetyl nitrate.
The formation of PAN can be represented by the following chemical equation:
NO2 + RO2 → PAN + NO
where RO2 represents a peroxyacyl radical formed from the reaction of a VOC (volatile organic compounds like Benzene, Formaldehyde, Tolune etc) with OH radicals in the atmosphere.

For Free Notes
For Free Mock Tests
Youtube channels for video solutions

Leave a Reply

Your email address will not be published. Required fields are marked *