Example of chemical weathering

Chemical weathering is the disintegration of a substance in the rock through a chemical reaction.

Carbonation occurs when water and a pollutant, such as sulphur dioxide creates a weak sulphuric acid. When it rains and the water comes into contact with limestone a chemical reaction happens. Calcium sulphate is produced as it takes the calcium carbonate from the limestone. It can then transfer the solution to another area until it evaporates. When it does so it leaves behind calcium information such as stalactites.

hydration occurs when minerals in a rock absorb water, causing it to expand. Mineral, such as anhydrite, expands and weakens it's structure and leave the rock more exposed to erosion.

oxidation occurs some substances react to being exposed to water or air. Iron, when exposed, will turn from a silver color to a red or dark brown color known as iron oxide. It weakens the rock.

hydrolysis occurs when water bonds with a mineral in the rock. It is particularly strong at weathering feldspars in rock and can lead to the formation of Kaolin.