Question

Describe chemical weathering, mentioning the processes involved in it.

Answer 1

Chemical weathering refers to the breakdown of rocks through chemical reactions that alter the mineral composition of the rocks. This process is largely driven by water, oxygen, carbon dioxide, and organic acids. The four main processes involved in chemical weathering are:

1. Solution: Minerals like salts, especially soluble minerals, dissolve in water, breaking down the rock.

2. Carbonation: Carbon dioxide reacts with minerals like calcium carbonate (in limestone) to form carbonic acid, which dissolves the minerals.

3. Oxidation: Oxygen reacts with iron-rich minerals in the rocks (e.g., haematite or magnetite), causing them to form iron oxide (rust), weakening the rock structure.

4. Hydration: Water interacts with minerals in rocks, causing them to absorb water, expand, and become heavier, which leads to the breakdown of the rock.