Question

Which of the following is a secondary pollutant?  

विकल्प

• CO

• NO

• SO₂

• SO₃

Answer 1

SO₃

Explanation:

SO₂, a primary air pollutant, reacts with O₂ to produce SO₃, a secondary air pollutant.

\[\ce{2SO2 + O2 → 2SO3}\]