Consider the following pairs :

Types of Chemical Weathering : Characteristics
I. Solution : Results in leaching of minerals
II. Carbonation : Helps in breaking down feldspars
III. Hydration : Causes an increase in the volume of rocks
IV. Oxidation : Changes the colour of rocks

How many pairs given above are correctly matched?

All four pairs are correctly matched based on the principles of chemical weathering:

• Solution: This process involves the dissolution of soluble minerals in water. As these minerals are removed in solution, it leads to the leaching of the rock material.
• Carbonation: This is the reaction of carbonate or bicarbonate with minerals. Carbonic acid (formed by water and atmospheric CO2) is highly effective in breaking down feldspars and carbonates into clay minerals.
• Hydration: It is the chemical addition of water to the molecular structure of a mineral. This process causes an increase in the volume of the minerals and the rock, leading to physical stress and disintegration.
• Oxidation: This occurs when minerals react with oxygen to form oxides or hydroxides. It is common in iron-bearing minerals and typically changes the colour of rocks to shades of red, yellow, or brown.