Correct Answer: b) (A) is false, but (R) is true.
Explanation:
1. Primary Contributors to Acid Rain:
– Sulfur Dioxide (SO₂):
– Sources: Combustion of fossil fuels (like coal and oil), volcanic eruptions, and certain industrial processes.
– Chemical Reaction: SO₂ reacts with water vapor in the atmosphere to form sulfuric acid (H₂SO₄).
– Nitrogen Oxides (NOₓ), Mainly Nitrogen Dioxide (NO₂):
– Sources: Vehicle emissions, power plants, and industrial activities.
– Chemical Reaction: NO₂ reacts with water to produce nitric acid (HNO₃).
2. Carbon Dioxide (CO₂) and Its Role:
– Sources: Respiration, combustion of carbon-based fuels, deforestation, and various industrial activities.
– Chemical Reaction: CO₂ dissolves in water to form carbonic acid (H₂CO₃).
– Impact: While carbonic acid does contribute to the acidity of rainwater, it is a weak acid and has a negligible effect on the overall acidity compared to sulfuric and nitric acids. Consequently, CO₂ is not considered a primary cause of acid rain.
Analyzing the Given Statements
1. Assertion (A): “CO₂, SO₂, and NO₂ gases get dissolved in rainwater and produce acid rain.”
– Accuracy: Incorrect. While SO₂ and NO₂ are significant contributors to acid rain, CO₂ plays a minor role and is not a primary cause.
2. Reason (R): “Atmospheric air is polluted due to high concentration of gases like carbon dioxide, sulphur dioxide and oxides of nitrogen.”
– Accuracy: Correct. The statement accurately identifies CO₂, SO₂, and NOₓ (including NO₂) as major pollutants that contribute to various environmental issues, including pollution and acid rain.