Acid rain is caused by the oxides of and .....

Question

Acid rain is caused by the oxides of  and .....

Accepted Answer

Explanation:

1. **Why Option 2 is Correct:**
   Acid rain is primarily caused by the presence of sulfur dioxide (SO₂) and nitrogen oxides (NOₓ) in the atmosphere. These compounds are released into the air through the burning of fossil fuels, industrial processes, and vehicle emissions. Once in the atmosphere, sulfur dioxide and nitrogen oxides react with water vapor, oxygen, and other chemicals to form sulfuric acid (H₂SO₄) and nitric acid (HNO₃). These acids then mix with rainwater, resulting in acid rain. Therefore, the oxides of sulfur and nitrogen are the main contributors to acid rain, making Option 2 the correct answer.

2. **Why Other Options are Incorrect:**
   - **Option 1 (Carbon, Phosphorus):** Carbon oxides, such as carbon dioxide (CO₂), do not contribute to acid rain. While CO₂ can dissolve in water to form carbonic acid, it is weak and does not significantly lower the pH of rainwater to the levels seen in acid rain. Phosphorus oxides are not significant contributors to acid rain either, as they are not commonly found in the atmosphere in forms that would lead to acid rain.
   
   - **Option 3 (Carbon, Nitrogen):** While nitrogen oxides are indeed a cause of acid rain, carbon oxides are not. As mentioned earlier, carbon dioxide forms a weak acid and is not a major factor in acid rain. Therefore, this option is incorrect because it includes carbon, which is not a primary contributor to acid rain.
   
   - **Option 4 (Nitrogen, Fluorine):** Although nitrogen oxides are involved in the formation of acid rain, fluorine compounds are not. Fluorine is not typically found in the atmosphere in forms that would contribute to acid rain. Therefore, this option is incorrect because it includes fluorine, which is not relevant to the formation of acid rain.

In conclusion, the correct answer is Option 2, as sulfur and nitrogen oxides are the primary causes of acid rain.