What rock like limestone dissolves in water and why does chalk and limestone dissolve in rainwater?
The three common rocks that dissolve are rock-salt gypsum and limestone. Dissolution of these rocks produces caves, sinkholes, sinking streams and large springs, creating a landscape known as karst. Limestone areas are predominantly affected by chemical weathering when rainwater, which contains a weak carbonic acid, reacts with limestone. This causes the limestone to dissolve.
Rainwater, especially in combination with atmospheric gases often resulting in acid rain can result in dissolution of the limestone, causing higher levels of salt movement within the stone structure. When sulfurous, sulfuric, and nitric acids in polluted air and rain react with the calcite in marble and limestone, the calcite dissolves. Chalk or CaCO3 is sparingly soluble in water and chalk hills do not normally dissolve in rain water. However, under acidic conditions like acid rain, bicarbonate ions are formed and calcium bicarbonate salt is soluble in water. 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. The limestone does not dissolve in water but it will form a solution same as that of mud and water. Two separate layers can be seen. If limestone is mixed with a mixture of carbon dioxide and water. It will form calcium hydrogen carbonate.Most groundwater contains some acid, in most cases carbonic acid. The acidic groundwater slowly dissolves any limestone that it comes in contact with. The CO2 combines with water to form carbonic acid. The slightly acidic water is especially good at dissolving the rock limestone. Groundwater creates landforms by dissolving away rock.
- Badges
- Science topic
- Similar topics
- Geoscience
- Atmospheric Sciences
- Atmosphere
- Air