Question

Which of the following statements about photochemical smog is not correct?
A) It occurs in a warm, dry, and sunny climate.
B) Chemically, it is a reducing mixture and is called reducing smog.
C) It is formed as a result of sunlight of unsaturated hydrocarbons and nitrogen oxides.
D) It has a high concentration of oxidizing agents and is also called oxidizing smog.

Answer 1

Hint: To answer this question you should know that ozone and nitric acid are two of the main components of photochemical smog. Now try to find whether these components are reducing agents or oxidizing agents.

Complete answer:
First, we should know that Photochemical smog is a type of smog produced when ultraviolet light from the sun reacts with nitrogen oxides and hydrocarbons in the atmosphere.
Photochemical smog is visible as a brown haze, and is most prominent during the morning and afternoon, especially in a densely populated, warm, dry, and sunny climate.
${ NO }_{ 2 }$ goes through a complex series of reactions when exposed to ultraviolet radiation, with hydrocarbons to produce the components of photochemical smog—a mixture of ozone, nitric acid, aldehydes, peroxyacyl nitrates (PANs) and other secondary pollutants
We should know that ${ NO }_{ 2 }$, ozone, and PANs are called photochemical oxidants because they can react and oxidize certain compounds in the atmosphere or within a person's lungs that are not normally oxidized.

Therefore, we can conclude that the correct answer to this question is option B.

Note: The main pollutant in photochemical smog is ozone. Besides ozone, there are also a number of other pollutants in photochemical smog. One of them is Peroxyacyl nitrate (PAN), this pollutant is notable for causing eye and respiratory irritation. It is also responsible for eye-watering when there is heavy pollution.
We should also know that another type of smog, "reducing smog", has high concentrations of sulfur dioxide, which is a reducing agent.