Which gas is a major contributor to acid rain from burning fossil fuels?

Which gas is a major contributor to acid rain from burning fossil fuels?

• A. Sulfur dioxide (SO2)
• B. Oxygen
• C. Carbon dioxide (CO2)
• D. Nitrogen dioxide (NO2)

Answer: (A)

When fossil fuels burn, sulfur compounds are released as sulfur dioxide. In the atmosphere, SO2 is oxidized to sulfur trioxide and then reacts with water to form sulfuric acid, which precipitates as acid rain. This makes sulfur dioxide a primary contributor to acid rain from fossil-fuel combustion. The other gases either don’t form strong acids in rain as readily (oxygen is not an acid-forming pollutant in this context, and carbon dioxide mainly affects climate, not rain acidity) or contribute less significantly than SO2 (nitrogen oxides do form nitric acid but are typically secondary to the impact of sulfur dioxide).

When fossil fuels burn, sulfur compounds are released as sulfur dioxide. In the atmosphere, SO2 is oxidized to sulfur trioxide and then reacts with water to form sulfuric acid, which precipitates as acid rain. This makes sulfur dioxide a primary contributor to acid rain from fossil-fuel combustion. The other gases either don’t form strong acids in rain as readily (oxygen is not an acid-forming pollutant in this context, and carbon dioxide mainly affects climate, not rain acidity) or contribute less significantly than SO2 (nitrogen oxides do form nitric acid but are typically secondary to the impact of sulfur dioxide).