Which of the following best explains why increasing temperature generally speeds up chemical reactions?

• A. Higher temperature decreases the activation energy required for the reaction to occur.
• B. Higher temperature increases the concentration of reactants.
• C. Higher temperature changes the chemical identity of the reactants.
• D. Higher temperature increases the kinetic energy of molecules, leading to more frequent and energetic collisions.

Answer: (D)

Verified step by step guidance

1. Understand that temperature is a measure of the average kinetic energy of molecules in a substance.
2. Recall the collision theory, which states that chemical reactions occur when reactant molecules collide with sufficient energy and proper orientation.
3. Recognize that increasing temperature increases the kinetic energy of molecules, causing them to 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 the increased frequency and energy of collisions at higher temperatures generally speed up chemical reactions.