Chemical weathering is the set of processes carried out by means of water or by gaseous agents in the atmosphere such as oxygen and carbon dioxide.
The rocks disintegrate more easily thanks to this type of weathering, since the mineral grains lose adhesion and dissolve or detach better when the physical agents act.
Dissolution: It consists of incorporating the molecules of a solid body into a solvent such as water. This system dissolves many sedimentary rocks composed of the salts that were left when the water that contained them in solution evaporated.
Hydration: It is the process by which water is chemically combined with a compound. When water molecules are introduced through the crystalline networks of the rocks, a pressure is produced that causes an increase in volume, which in some cases can reach 50%. When these transformed materials are dried, the opposite effect occurs, a contraction is generated and they are broken.
Oxidation: Oxidation is caused by the action of oxygen, usually when it is released into water. In oxidation there is a simultaneous reduction, since the oxidizing substance is reduced by taking possession of the electrons that lose the oxidized. The rocky substrates of reddish, ocher or brownish tones, so abundant, are produced by the oxidation of the iron contained in the rocks.
Hydrolysis: It is the chemical decomposition of a substance by water, which in turn also decomposes. In this process, water is transformed into ions that can react with certain minerals, to which they break their crystalline networks. This is the process that has caused most clay materials we know.
Carbonation: It consists of the ability of carbon dioxide to act on its own, or to dissolve in water and form carbonic acid in small amounts. Carbonated water reacts with rocks whose predominant minerals are calcium, magnesium, sodium or potassium, giving rise to carbonates and bicarbonates.
Biological action: The mineral components of the rocks can be decomposed by the action of substances released by living organisms, such as nitric acids, ammonia and carbon dioxide, which enhance the eroding action of water.
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