The reaction rate of a reaction at 60 °C will be greater than at 30 °C because:

• A. the molecules have higher kinetic energy, leading to more frequent and energetic collisions
• B. the activation energy of the reaction decreases as temperature increases
• C. the reaction becomes exothermic at higher temperatures
• D. the concentration of reactants increases automatically with temperature

Answer: (A)

Verified step by step guidance

1. Understand that reaction rate depends on how often and how effectively molecules collide with each other.
2. Recall that increasing temperature increases the average kinetic energy of molecules, making them move faster.
3. Recognize that faster-moving molecules collide more frequently and with greater energy, increasing the chance of overcoming the activation energy barrier.
4. Know that activation energy is a fixed energy barrier for a given reaction and does not decrease simply because temperature increases.
5. Conclude that the main reason the reaction rate increases with temperature is due to higher kinetic energy causing more frequent and energetic collisions, not changes in activation energy, reaction exothermicity, or reactant concentration.