Which of the following best describes how increasing temperature affects the rate of a chemical reaction?

• A. It increases the rate by providing reactant molecules with more kinetic energy, leading to more frequent and energetic collisions.
• B. It decreases the rate by causing reactant molecules to move more slowly and collide less often.
• C. It increases the rate only if a catalyst is present.
• D. It has no effect on the rate of a chemical reaction.

Answer: (A)

Verified step by step guidance

1. Understand that the rate of a chemical reaction depends on how often and how effectively reactant molecules collide with each other.
2. Recall the collision theory, which states that molecules must collide with sufficient energy (activation energy) and proper orientation for a reaction to occur.
3. Recognize that increasing temperature increases the average kinetic energy of molecules, making them move faster.
4. Faster-moving molecules collide more frequently and with greater energy, increasing the likelihood that collisions overcome the activation energy barrier.
5. Conclude that increasing temperature generally increases the reaction rate by providing reactant molecules with more kinetic energy, leading to more frequent and energetic collisions.