Statement I : Oxides of sulfur and nitrogen present in high concentration in air are dissolved in rain drops. Statement II : Oxyacids of sulfur and nitrogen make rain water acidic.

Statement I is true as the atmosphere receives oxides of sulfur (SO2) and nitrogen (NOx) from industrial and natural sources, which are subsequently dissolved in raindrops or moisture [2]. Statement II is also true and provides the correct explanation for the first statement. These oxides undergo reactive dissolution and oxidation in the atmosphere to form oxyacids, specifically sulfuric acid (H2SO4) and nitric acid (HNO3) [4]. For instance, sulfur dioxide reacts with water to form sulfurous acid or is oxidized to sulfur trioxide to form sulfuric acid. Similarly, nitrogen dioxide reacts with water or hydroxyl radicals to form nitric and nitrous acids [4]. The presence of these oxyacids in precipitation significantly lowers the pH of rainwater, typically below 5.6, resulting in the phenomenon known as acid rain [5].

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > 5.15.4. Chemistry of Acid Rain > p. 103
2. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > Acidification > p. 8
3. [4] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > 5.I5. ACID RAIN > p. 101
4. [5] https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=20013K3B.TXT