JEE Main 2021 — Environmental Chemistry Question with Solution

Option A

Both Statement I and Statement II are true.

Explanation :

The pH of pure water is 7, which is considered neutral. However, rainwater is naturally slightly acidic due to the presence of dissolved carbon dioxide, which reacts with the water to form carbonic acid. The pH of "normal" rainwater is around 5.6 because of this natural process.

Acid rain is a term that refers to any form of precipitation with acidic components, such as sulfuric or nitric acid, that fall to the ground from the atmosphere in wet or dry forms. This can include rain, snow, fog, hail or even dust that is acidic. The increased acidity in rain is caused by high amounts of pollutant components such as sulfur and nitrogen compounds which react in the atmosphere with water, oxygen, and other chemicals to form sulfuric and nitric acid. These then fall to the ground as acid rain. The generally accepted definition of "acid rain" refers to rainfall with a pH of less than 5.6, which is more acidic than normal rainwater.