Weathering release occurs of Ca and other ions into surface waters. Rainfall is acidic because atmospheric carbon dioxide dissolves in the rainwater producing weak carbonic acid. In unpolluted environments, the rainfall pH is around 5.6. Acid rain occurs when gases such as sulfur dioxide and nitrogen oxides are present in the atmosphere. These oxides react in the rain water to produce stronger acids and can lower the pH to 4.5 or even 3.0. Sulfur dioxide, SO, comes from volcanic eruptions or from fossil fuels, can become sulfuric acid within rainwater, which can cause solution weathering to the rocks on which it
Sulfur dioxide Sulfur dioxide Sulfur dioxide (also sulphur dioxide in British English) is the chemical compound with the formula . It is a toxic gas with a burnt match smell. It is released naturally by volcanic activity and is produced as a by-product of the burning of fossil fuels contaminated with sulfur compounds and copper extraction. SO is a bent molecule with "C" symmetry point group. A valence bond theory approach considering just "s" and "p" orbitals would describe the bonding in terms of resonance between two resonance structures. The sulfur–oxygen bond has a bond order of 1.5. There is support for