Which pollutant is most commonly associated with acid rain?

The pollutant most commonly associated with acid rain is nitrogen oxides. When fossil fuels are burned, nitrogen in the air combines with oxygen to form nitrogen oxides, which then enter the atmosphere. These nitrogen oxides can react with water vapor and other chemicals in the atmosphere to create nitric acid, a significant component of acid rain.

The formation of acid rain primarily involves the interaction of sulfur dioxide and nitrogen oxides with atmospheric moisture, leading to the production of sulfuric and nitric acids. These acids can then precipitate back to the Earth's surface as acid rain, which can have harmful effects on ecosystems, water sources, and human structures.

Understanding the role of nitrogen oxides in the formation of acid rain underscores the importance of controlling emissions from vehicles and industrial processes, as addressing these can significantly reduce acid rain and its detrimental environmental impacts.