Explain why increasing temperature generally increases the rate of a chemical reaction.

• A. Higher temperature decreases particle collisions.
• B. Higher temperature increases particle collisions and energy, making more collisions successful.
• C. Temperature has no effect on reaction rate.
• D. Higher temperature changes the reaction to endothermic only.

Answer: (B)

Raising temperature increases the rate of a chemical reaction because it boosts the average kinetic energy of the reacting particles. With more energy, particles move faster, so they collide more often (higher collision frequency). When they do collide, the higher energy means a greater chance that the collision has enough energy to overcome the activation energy barrier needed to break old bonds and form new ones. In other words, more collisions occur and a larger fraction of those collisions are successful, speeding up the reaction. The idea is also reflected in the Arrhenius relationship, where the rate constant rises as temperature increases.

The other statements don’t fit what actually happens: increasing temperature does not decrease collisions, it does affect the rate, and temperature does not change the character of the reaction to endothermic only.