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. Solution weathering involves dissolving of soluble minerals like rock salt and gypsum, leading to leaching. Carbonation involves reaction of carbonic acid with minerals like feldspar, breaking them down into clay minerals. Hydration involves absorption of water by minerals, causing them to swell and increase in volume (e.g., anhydrite becoming gypsum). Oxidation, particularly of iron-bearing minerals, changes the colour of rocks to reddish-brown due to formation of iron oxides. Hence, all four pairs are correct.