Question

The major photochemical oxidant is:

• A. H\(_2\)O\(_2\)
• B. O\(_3\)
• C. NO
• D. Peroxy acetyl nitrate (PAN)

Hint:

Photochemical smog is often referred to as ozone smog due to the dominance of O\(_3\).

Answer 1

The Correct Option is B

Step 1: Understanding photochemical oxidants.
Photochemical oxidants are secondary air pollutants formed by reactions of nitrogen oxides and hydrocarbons in the presence of sunlight.
Step 2: Formation of ozone.
Ground-level ozone is produced when NO\(_x\) and volatile organic compounds react under sunlight. It is the most abundant and reactive photochemical oxidant in the atmosphere.
Step 3: Evaluating the options.
(A) H\(_2\)O\(_2\): Not the major photochemical oxidant in ambient air.
(B) O\(_3\): Correct, ozone is the principal photochemical oxidant.
(C) NO: A precursor pollutant, not an oxidant.
(D) PAN: A secondary pollutant, but not the major oxidant.
Step 4: Conclusion.
The major photochemical oxidant present in photochemical smog is ozone (O\(_3\)).