How does increasing temperature affect the rate of a reaction that has a catalyst present?

How does increasing temperature affect the rate of a reaction that has a catalyst present?

• A. It decreases the rate.
• B. It increases the rate by increasing the fraction of molecules with energy above activation energy.
• C. It has no effect due to the catalyst.
• D. It reverses the direction of the reaction.

Answer: (B)

Raising temperature speeds up a reaction because more molecules have enough energy to get over the activation energy barrier. A catalyst provides a lower-energy pathway, so the threshold is easier to reach. With the activation energy lowered, the rise in temperature increases the fraction of molecules energetic enough to react even more, leading to a faster rate. This is consistent with the Arrhenius idea that rate constants grow with temperature.

Raising temperature speeds up a reaction because more molecules have enough energy to get over the activation energy barrier. A catalyst provides a lower-energy pathway, so the threshold is easier to reach. With the activation energy lowered, the rise in temperature increases the fraction of molecules energetic enough to react even more, leading to a faster rate. This is consistent with the Arrhenius idea that rate constants grow with temperature.