How is sulfur dioxide related to acid rain?

Sulfur dioxide (SO₂) plays a significant role in the formation of acid rain through its ability to react with water in the atmosphere. When sulfur dioxide is released into the air, it can undergo a series of chemical reactions that ultimately lead to the formation of sulfuric acid (H₂SO₄) when it combines with water vapor.

This process can be summarized as follows:

1. Sulfur dioxide reacts with oxygen in the atmosphere to form sulfur trioxide (SO₃).

2. The sulfur trioxide then reacts with water to produce sulfuric acid.

3. This newly formed sulfuric acid can dissolve in water droplets present in clouds, leading to increased acidity in rainwater.

As a result, when it rains, the water can become more acidic due to the presence of sulfuric acid, contributing to what is known as acid rain. This increase in acidity can have harmful effects on ecosystems, buildings, and water sources. Therefore, the correct connection is that sulfur dioxide forms solutions of sulfuric acid when it interacts with water.