Question

Write down the reactions involved during the formation of photochemical smog.

Answer 1

Hint: The formation of photochemical smog occurs as a result of the reaction of sunlight with hydrocarbons and nitrogen oxides. Common components of the photochemical smog are ozone, formaldehyde, nitric oxide, acrolein and peroxyacetyl nitrate.

Complete step by step answer:
-The formation of photochemical smog occurs during a dry and sunny climate.
-Common components of the photochemical smog are ozone, formaldehyde, nitric oxide, acrolein and peroxyacetyl nitrate.
-The photochemical smog is oxidizing in nature.
-The formation of photochemical smog occurs as a result of the reaction of sunlight with hydrocarbons and nitrogen oxides.
-The reactions involved during the formation of photochemical smog are as follows:
-Nitrogen dioxide is converted to nitric oxide in presence of sunlight. Nascent oxygen is formed during this reaction. The reaction is as follows:
${\text{N}}{{\text{O}}_{\text{2}}}\left( g \right)\xrightarrow{{h\nu }}{\text{NO}}\left( g \right) + {\text{O}}\left( g \right)$
-The nascent oxygen reacts with oxygen to produce ozone. This is a reversible reaction. The reaction is as follows:
${\text{O}}\left( g \right) + {{\text{O}}_{\text{2}}}\left( g \right) \leftrightarrow {{\text{O}}_{\text{3}}}\left( g \right)$
-The ozone reacts with nitric oxide to produce nitrogen dioxide and oxygen gas. The reaction is as follows:
${{\text{O}}_{\text{3}}}\left( g \right) + {\text{NO}}\left( g \right) \to {\text{N}}{{\text{O}}_{\text{2}}}\left( g \right) + {{\text{O}}_{\text{2}}}\left( g \right)$
-The ozone also reacts with methane gas to produce formaldehyde and water. The reaction is as follows:
${\text{2}}{{\text{O}}_{\text{3}}} + {\text{3C}}{{\text{H}}_{\text{4}}} \to {\text{3C}}{{\text{H}}_{\text{2}}} = {\text{O}} + {\text{3}}{{\text{H}}_{\text{2}}}{\text{O}}$

Note: The reactions occurring during the formation of photochemical smog are:
-Nitrogen dioxide is converted to nitric oxide in presence of sunlight. Nascent oxygen is formed during this reaction.
-The nascent oxygen reacts with oxygen to produce ozone.
-The ozone reacts with nitric oxide to produce nitrogen dioxide and oxygen gas.
-The ozone also reacts with methane gas to produce formaldehyde and water.