Acid rain is produced by volcanic eruptions. Acid rain has been shown to have adverse impacts on forests, freshwaters and soils, killing insect and aquatic life-forms, causing paint to peel, corrosion of steel structures such as bridges, and weathering of stone buildings and statues as well as having impacts on human health. "Acid rain" is a popular term referring to the deposition of a mixture from wet (rain, snow, sleet, fog, cloudwater, and dew) and dry (acidifying particles and gases) acidic components. Distilled water, once carbon dioxide is removed, has a neutral pH of 7. Liquids with a pH less than 7
Hexafluorosilicic acid 99% hydrolysis occurs and the pH drops. The rate of hydrolysis increases with pH. At the pH of drinking water, the degree of hydrolysis is essentially 100%. Neutralization of solutions of hexafluorosilicic acid with alkali metal bases produces the corresponding alkali metal fluorosilicate salts: The resulting salt NaSiF is mainly used in water fluoridation. Related ammonium and barium salts are produced similarly for other applications. Near neutral pH, hexafluorosilicate salts hydrolyze rapidly according to this equation: The majority of the hexafluorosilicic acid is converted to aluminium fluoride and cryolite. These materials are central to the conversion of aluminium ore into