`SO_2` and `NO_2` cause pollution by increasing

Options

A. Acidity
B. Alkalinity
C. Buffer action
D. Both (a) and C

Answer

To solve the question regarding how `SO2` (sulfur dioxide) and `NO2` (nitrogen dioxide) cause pollution, we can follow these steps:

### Step 1: Understanding the Compounds
Both `SO2` and `NO2` are gases that can contribute to environmental pollution. They are known for their role in forming acid rain.

### Step 2: Reaction with Water
When `SO2` and `NO2` come into contact with water vapor in the atmosphere, they undergo chemical reactions:
- `SO2` reacts with water to form sulfuric acid (`H2SO4`).
- `NO2` reacts with water to form nitric acid (`HNO3`).

### Step 3: Formation of Acidic Compounds
Both sulfuric acid and nitric acid are strong acids. This means that the presence of these compounds in the atmosphere increases the acidity of rainwater.

### Step 4: Impact on the Environment
When acid rain falls to the ground, it can have detrimental effects on soil and vegetation. The increased acidity can lead to:
- Soil becoming barren and less fertile.
- Harm to plant life, making it difficult for vegetation to grow.

### Step 5: Conclusion
From the above analysis, we can conclude that `SO2` and `NO2` cause pollution primarily by increasing the acidity of the environment, leading to the phenomenon known as acid rain.

### Final Answer
`SO2` and `NO2` cause pollution by increasing acidity.

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