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

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

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 that temperature is a measure of the average kinetic energy of molecules in a substance; increasing temperature means molecules move faster on average.
3. Recognize that faster-moving molecules collide more frequently and with greater energy, increasing the chances that collisions overcome the activation energy barrier.
4. Know that activation energy is the minimum energy required for a reaction to proceed, but temperature does not change this energy threshold itself.
5. Conclude that increasing temperature increases the average kinetic energy of reactant molecules, leading to more frequent and energetic collisions, which increases the reaction rate.