Why does an increase in temperature result in an increase in reaction rate?

• A. Because more reactant molecules have enough kinetic energy to overcome the activation energy barrier.
• B. Because the concentration of reactants increases with temperature.
• C. Because the products become more stable at higher temperatures.
• D. Because the activation energy of the reaction decreases as temperature increases.

Answer: (A)

Verified step by step guidance

1. Understand that reaction rate 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 system.
3. Recognize that increasing temperature increases the average kinetic energy of reactant molecules, making collisions more energetic.
4. Know that only molecules with kinetic energy equal to or greater than the activation energy can successfully react; this is described by the Arrhenius equation: \(k = A e^{-\frac{E_a}{RT}}\), where \(k\) is the rate constant, \(E_a\) is activation energy, \(R\) is the gas constant, and \(T\) is temperature in Kelvin.
5. Conclude that as temperature increases, a larger fraction of molecules have enough energy to overcome the activation energy barrier, thus increasing the reaction rate.