Which two factors most commonly increase the rates of chemical reactions and weathering in rocks and soils?

• A. Lower concentration and higher pressure
• B. Decreased humidity and reduced catalyst presence
• C. Higher temperature and increased surface area
• D. Lower temperature and decreased surface area

Answer: (C)

Verified step by step guidance

1. Understand that the rate of chemical reactions generally depends on factors that affect how often and how energetically reactant particles collide.
2. Recognize that higher temperature increases the kinetic energy of particles, leading to more frequent and more energetic collisions, which typically increases reaction rates.
3. Know that increased surface area exposes more reactant particles to each other, allowing more collisions to occur simultaneously, thus speeding up the reaction.
4. Consider that factors like lower concentration or lower temperature usually decrease reaction rates, while catalysts can increase rates by lowering activation energy.
5. Apply these principles to weathering in rocks and soils, where higher temperature and increased surface area (e.g., from rock fragmentation) commonly accelerate chemical weathering processes.