Question

One of the major photochemical oxidant is:
A.$O_3$
B.$H_2{O}_2$
C.Nitrogen oxides
D.Peroxyacetyl nitrate (PAN)

Answer 1

Hint:
Photochemical oxidants are basically a mixture of the primary and secondary air pollutants found in photochemical smog. There are various components present in photochemical oxidants that cause pollution.

Complete step by step answer:
Photochemical oxidants:
Photochemical oxidants are the product of reactions that occur between nitrogen oxides and volatile organic compounds (VOC’s).
Volatile organic compounds are those compounds that can evaporate easily. They are highly flammable.
These compounds are mainly released from burning of coal, wood and gasoline.
Also when these react with nitrogen oxides, very high concentrations of ozone is formed which causes an adverse effect on the environment.
The most commonly known photochemical oxidants are ozone, hydrogen peroxides and peroxyacetyl nitrate (PAN).
These are formed under the influence of sunlight by complex photochemical reactions.
The concentrations of the photochemical oxidants depend on the primary pollutants and the sunlight.
Other compounds that are also formed such as aldehydes, ketones, aerosol and nitrogen dioxide.
Many of these oxidants are also released from the air pollution that is caused because of the emissions from vehicles.
Photochemical oxidants are very harmful to human, animal and aquatic life.
It causes painful irritation in the respiratory tract, difficulty in breathing, reduced lung function.
People who are sensitive to ozone, that is people who already have respiratory health issues , are likely to be more affected.
Therefore, the correct answer is option C nitrogen oxides.

Note:Although all the components are major components of photochemical oxidants but most of the components are produced from nitrogen oxides. That is why it is considered a major component. These photochemical oxidants are the part of photochemical smog.