How does temperature influence chemical reaction rates in the environment?

• A. Temperature decreases reaction rates.
• B. Temperature has no effect on reaction rates.
• C. Higher temperature generally increases reaction rates by providing more energy to overcome activation barriers.
• D. Temperature only affects phase changes, not reactions.

Answer: (C)

Temperature changes the kinetic energy of molecules, which affects how fast reactions occur. When it gets warmer, particles move more quickly, so they collide more often and with greater energy. A reaction can only happen if collisions have enough energy to overcome the activation barrier; higher temperature increases the fraction of collisions with that energy, so the overall rate goes up. In environmental chemistry, this helps explain why warmer conditions often speed up processes like pollutant degradation or oxidation. Of course, extremely high temperatures can damage reactants or enzymes and change the pathways, but the general trend is clear: higher temperature tends to increase reaction rates. The other statements don’t fit because cooling doesn’t promote faster reactions, temperature does affect rates, and it influences more than just phase changes.