Question

How is SO₂ an air pollutent ?

Answer 1

1. SO₂ is strongly irritating to the respiratory tract. SO₂ at a concentration of 5 ppm causes throat and eyes irritation causing cough, tears and redness in eyes. It causes breathlessness and affects larynx. i.e, voice box.

2. SO₂ dissolves in rain water and produces H₂SO₄ which demages building materials especially marble (CaCO₃).
CaCO₃ + H₂SO₃ → CaSO₃ + H₂O + CO₂ ↓