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Home Up Type of Rocks Physical Weathering Chemical Weathering Factors

 

Chemical weathering  is the process by which rocks are decomposed, dissolved or loosened by chemical processes to form residual materials. Some of the proc

Processes involved in chemical weathering are given below :

CARBONATION 
process by which dissolved carbon dioxide in rainwater or moisture in  surrounding air forms carbonic acid and reacts with the minerals in the rock. This process weakens the rock thus breaking it down in the process.

e.g.: Calcium Carbonate + Water + Carbon Dioxide ---> Calcium Carbonate (soluble)

HYDROLYSIS 

chemical reaction between the minerals in the rock and hydrogen in rain  water. For example, during hydrolysis, the feldspar in granite changes to claymineral which crumbles easily, weakening the rock and causing it to break down.

OXIDATION 
The process by which oxygen combine with water and minerals in the rock  such as calcium and magnesium. When iron reacts with oxygen, reddish -brown   iron oxide is formed. The iron-oxide crust crumbles easily and weakens the rock.

e.g. : Iron + Oxygen -->  Iron Oxide (crumbles)

SOLUTION    
process by which minerals in the rocks dissolve directly in water.

 

HYDRATION
process where minerals in the rock absorb water and expand, creating stress which causes the disintegration of rocks.

EG: Unhydrated Calcium sulphate + Water -->   Hydrated Calcium Sulphate (expands)

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