Q1: A rainfall may be classified as acidic if its pH value is less or equal to

ANS:C - 5

A rainfall may be classified as acidic if its pH value is less than or equal to 5.6. Rainfall with a pH value below 5.6 is considered acidic. However, the threshold for what is considered acidic can vary depending on the source and context. Some sources may consider a pH value of 5.0 or lower as the threshold for acidic rainfall. It's important to note that rainfall becomes acidic primarily due to the presence of pollutants such as sulfur dioxide and nitrogen oxides, which can form sulfuric acid and nitric acid when they react with water vapor in the atmosphere. This phenomenon is commonly known as acid rain and can have detrimental effects on the environment, including harming aquatic life, damaging vegetation, and corroding buildings and infrastructure.