What acid is formed when sulfur dioxide reacts with water?

When sulfur dioxide reacts with water, it forms sulfurous acid (H₂SO₃), which can further oxidize to form sulfuric acid (H₂SO₄) under the right conditions. This process is significant in the context of environmental chemistry, as the formation of sulfuric acid can contribute to acid rain. The chemical equation for the reaction of sulfur dioxide with water is:

SO₂ (g) + H₂O (l) → H₂SO₃ (aq)

This sulfurous acid can further react with oxygen in the atmosphere to produce more sulfuric acid:

2 H₂SO₃ + O₂ → 2 H₂SO₄

Understanding this reaction is crucial for wastewater treatment operations, as sulfur compounds can be pollutants that impact water quality. Therefore, recognizing sulfuric acid as the ultimate product formed from the reaction of sulfur dioxide and water is important for environmental monitoring and control measures in wastewater treatment facilities.