Which of the following best explains why increasing the temperature increases the rate of a chemical reaction?

• A. It increases the concentration of reactants in the reaction mixture.
• B. It changes the chemical identity of the reactants, making them more reactive.
• C. It decreases the activation energy required for the reaction to occur.
• D. It increases the average kinetic energy of the molecules, leading to more frequent and energetic collisions.

Answer: (D)

Verified step by step guidance

1. Understand that the rate of a chemical reaction depends on how often and how effectively reactant molecules collide.
2. Recall that temperature is a measure of the average kinetic energy of molecules in a substance.
3. Recognize that increasing temperature increases the average kinetic energy of molecules, causing them to move faster.
4. Faster-moving molecules collide more frequently and with greater energy, increasing the chances that collisions overcome the activation energy barrier.
5. Conclude that this leads to an increased reaction rate because more collisions have enough energy to result in a reaction.