Coal is a fossil fuel and in constant debates for its negative impacts on the environment. Which elements does it consist of and which products are being formed when it is burned? Give two examples for the effects on the environment.

(a) Coal contains  Carbon (80%) Sulfur (9%) Oxygen (5%) Hydrogen (1%) other elements (5%) (b) Carbondioxide (CO2) Sulfurdioxide (SO2) Water  (H2O) (c)  Carbon dioxide: Global warming (green house effect) Sulfur dioxide: Acidic Rain  2 SO₂ + O₂ → 2 SO₃ SO₂ + H₂O → H₂SO₃ SO₃ + H₂O → H₂SO₄