Question

What is chemical weathering? Give examples.

Answer 1

Hint:The process of breakdown or dissolution of rocks and minerals that are on the Earth's surface in regular intervals of time is weathering. When a rock has been broken down, a mechanism known as erosion carries the rock and mineral fragments further.There are no rocks upon the Earth that are capable of withstanding the effects of erosion or weathering.

Complete answer:
Weathering in general is just the phenomenon that is caused by the rocks on the earth due to factors like minerals, animals, plants, acids or water, and many more. Chemical weathering can occur as a result of chemical reactions that change the nature of rocks. The minerals on the surface of rocks are now developing more kinds of minerals as a result of long, steady, and continuing processes that later lead to causing hydration and oxidation to happen.

This process is helped by other agents such as water and oxygen, as they produce acids from microbial and plant root reactions with the help of oxygen and water. This type of weathering, the chemical weathering, is a worldwide occurring phenomenon, but it is most commonly done in places with climates like that of the tropical areas.

Some examples of chemical weathering are;
-Sometimes traveling water bodies have the power to cause erosion to rocks, resulting in a salty or saline solution. This splitting up of particles with the help of molecules of water is the mechanism involved. This is referred to as the hydrolysis method of chemical weathering.

-We know that the element oxygen is quite reactive. The phenomenon of oxidation takes place as oxygen comes into contact with rocks. The formation of rust is one such example of this weathering caused by the oxidation process; it happens as iron is reacted upon by oxygen thus forming rust or iron oxide. Rust alters the appearance of the minerals, and since rust that is iron oxide is much more brittle than iron, the weathered area is more prone to breakage.

-Other organisms like lichens have a major impact on the earth's surface rocks. Lichens are a mix of fungi and algae that contain an acid that is weak but it is very well capable of dissolving rock. Weathering occurs as a result of such dissolution.

Note: Another type of weathering is the biological weathering. This type of weathering is promoted by plants or animals, and even by microorganisms. People can induce biological weathering by simply having walked. Plant roots can cause biological weathering in some cases, but if they contain organic acids, they can also conduct chemical weathering.