Question

The acids present in acid rain are:

(i) Peroxyacetylnitrate

(ii) H₂CO₃ 

(iii) HNO₃

(iv) H₂SO₄ 

Answer 1

(ii) H₂CO₃ 

(iii) HNO₃

(iv) H₂SO₄  

Explanation:

Since rainwater has a pH of 5.6 due to the presence of H⁺ ions formed by the reaction of rainwater with carbon dioxide present in the atmosphere. The reactions can be shown as-

\[\ce{H2O (l) + CO2 (g) -> H2CO3 (aq)}\]

\[\ce{H2CO (aq) -> H+ (aq) + HCO3 (aq)}\]

If the pH of the rainwater falls below 5.6 then it is known as acid rain. SO₂ and NO₂ after oxidation and reaction with water are major contributors to the acid rain.

\[\ce{2SO2 (g) + O2 (g) + 2H2O (l) -> 2H2SO4 (aq)}\]

\[\ce{4NO2 (g) + O2 (g) + 2H2O (l) -> 4HNO^{-}3 (aq)}\]