Coal from western states such as Montana and Wyoming is known to have a lower percentage of sulfur impurities than coal found in the eastern United States. How would burning more sulfur-enriched coal in the eastern US affect the level of acidity in rainfall? Support your answer with chemical equations ...

Burning more sulfur-enriched coal in the eastern US would result in higher levels of acidity in rainfall.

Explanation:

Acid rain is a result mainly of the production of sulfur dioxide, SO₂, which accompanies the combustion of coal with high sulfur content in power generating plants. Sulfur dioxide is slowly converted into SO₃ by the reaction with oxygen in the air and its dissolution in rainwater, which produces diluted sulfuric acid, H₂SO₄.

First, the sulfur in coal is transformed into sulfur dioxide by the reaction with oxygen during burning:

S (s) + O₂ (g) ⇒ SO₂ (g)

Sulfur dioxide rises into the atmosphere and part of it oxidizes, becoming sulfur trioxide:

2 SO₂ (g) + O₂ (g) ⇒ 2 SO₃ (g)

Finally, sulfur dioxide and sulfur trioxide react with the water formed in the rains to form sulfurous acid and sulfuric acid respectively:

SO₂ (g) + H₂O (l) ⇒ H₂SO₃ (aq)

SO₃ (g) + H₂O (l) ⇒ H₂SO₄ (aq)