Answer: Peroxyacetyl nitrate (PAN).
- A Peroxyacetyl nitrate (PAN)
- B Sulfur dioxide
- C Carbon monoxide only
- D Hydrogen sulfide
Correct answer: A. Peroxyacetyl nitrate (PAN)
Explanation: Photochemical smog is oxidising and contains ozone, PAN and aldehydes formed from NO<sub>x</sub> and hydrocarbons in sunlight; PAN is a typical eye-irritant component.
Classical smog is a reducing mixture of SO₂ and fog, while photochemical smog is an oxidising mixture generated by UV-driven reactions of NOx and hydrocarbons.
Concept context
Understand how human activities alter the atmosphere, water, and soil. Covers air pollutants, smog types, ozone depletion, acid rain, greenhouse effect, water and soil pollution, and the principles of green chemistry.