What is the process where acidic rainwater dissolves rocks like limestone and chalk and process of acid rain wearing away limestone?
Chemical Weathering occurs when weak acids in rainwater attack and break down rock surfaces. Some types of rock are easily weathered by chemicals. When acidic rainwater falls on limestone or chalk, a chemical reaction occurs and the rock is weathered.Chemical weathering describes the process of chemicals in rainwater making changes to the minerals in a rock. Carbon dioxide from the air is dissolved in rainwater, making it slightly acidic. A reaction can occur when the rainwater comes into contact with minerals in the rock, causing weathering.
Lakes that have been acidified by acid rain can be neutralized by liming, the addition of limestone. When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. In exposed areas of buildings and statues, we see roughened surfaces, removal of material, and loss of carved details. Because surface waters are in equilibrium with atmospheric carbon dioxide there is a constant concentration of carbonic acid, H2CO3, in the water. The presence of limestone and other calcium carbonate rock in lakes and streams helps to maintain a constant pH because the minerals react with the excess acid. Weathering caves being formed by acid rain dissolving underground limestone. Weathering water getting into cracks, freezing, and breaking the rocks or pavement apart. The chemistry of limestone and groundwater can combine to make for sinkholes or vertical holes in bedrock that open up quickly. Sinkholes happen because groundwater, percolating downward from the land surface, is acidic, so it eats away at limestone, dissolving it. Although it is a slower process in nature, this same reaction happens to limestone acidic rain reacts with it, producing carbon dioxide.
- Badges
- Science topic
- Similar topics
- Geoscience
- Cartography
- Mapping
- Maps