Correct Option
The correct option is 1 only
Explanation
Soil formation, or pedogenesis, is fundamentally driven by weathering, an exogenic process. Climatic factors, particularly temperature and moisture, act as the primary regulators of the rate at which parent rock decomposes chemically and disintegrates physically.
Statement-wise Analysis
- Statement 1 is Correct: Chemical weathering involves reactions such as hydrolysis, oxidation, and carbonation. Following the general principles of chemical kinetics (specifically Van't Hoff's rule), the rate of chemical reactions increases with a rise in temperature. Consequently, warm climates, such as the humid tropics, experience intense chemical activity and deeper soil formation.
- Statement 2 is Incorrect: Lower temperatures reduce the kinetic energy available for chemical reactions, thereby slowing down chemical decomposition. In cooler climates, the rate of chemical weathering is significantly retarded compared to warmer regions.
- Statement 3 is Incorrect: In freezing conditions, water is locked in a solid state (ice) and is unavailable to act as a medium for chemical reactions. Furthermore, the low thermal energy means that chemical activity practically ceases or becomes negligible, though physical weathering (like frost wedging) may continue.
Key Takeaway: The rate of chemical weathering is directly proportional to temperature and moisture availability; it accelerates in hot conditions and becomes negligible in freezing conditions.