How does combustion of fossil fuels contribute to acid rain?

The combustion of fossil fuels contributes to acid rain primarily by releasing sulfur impurities found in these fuels. When fossil fuels such as coal, oil, and natural gas are burned, sulfur dioxide (SO₂) is produced as a byproduct. This gas can react in the atmosphere with water vapor and oxygen to form sulfuric acid (H₂SO₄).

This process occurs through a series of chemical reactions where sulfur dioxide is first oxidized to sulfur trioxide (SO₃), which can then combine with water to form sulfuric acid. The sulfuric acid can be carried by rain, entering the ecosystem as acid rain, which can have harmful effects on plants, aquatic life, and infrastructure.

In contrast, the other choices do not directly contribute to acid rain in the same manner. Carbon monoxide, while a harmful pollutant, does not form acids in the atmosphere. The heat generated from combustion does not directly relate to the formation of acids or ozone depletion. Lastly, fossil fuel combustion does not remove moisture from the atmosphere; it can actually contribute to changes in atmospheric water content due to the release of water vapor during combustion. Thus, the process of releasing sulfur impurities that result in sulfuric acid formation is the key pathway through which fossil fuel combustion leads