Here's why:
* Natural Rainwater: Natural rainwater is slightly acidic due to the presence of dissolved carbon dioxide (CO₂), which forms carbonic acid (H₂CO₃).
* Acid Rain: Acid rain is formed when sulfur dioxide (SO₂) and nitrogen oxides (NOx) are released into the atmosphere, primarily from burning fossil fuels. These gases react with water, oxygen, and other substances to form sulfuric acid and nitric acid (HNO₃).
* Increased Acidity: Sulfuric acid is a strong acid, and its presence significantly increases the acidity of rainwater, making it more acidic than natural rainwater.
So, while both sulfuric acid and nitric acid contribute to acid rain, sulfuric acid is the primary culprit for its increased acidity.
