Question

question 13 (1 point)
if a positive catalyst is added while a reaction is in progress and the energy barrier is
reduced, how does it affect the rate of reaction?
rate of the reaction first decreases and then increases.
rate of the reaction first increases and then decreases.
rate of reaction increases.
rate of reaction decreases.
it does not have any effect on the rate of reaction.
question 14 (1 point)

Explanation:

A positive catalyst lowers the activation energy (energy barrier) of a reaction. According to the collision theory, when the activation energy is reduced, more reactant molecules have sufficient energy to overcome the energy barrier and collide effectively. This leads to an increase in the number of successful collisions per unit time. Since the rate of reaction is directly related to the number of successful collisions, adding a positive catalyst that reduces the energy barrier will increase the rate of reaction. There is no reason for the rate to first decrease or increase and then change in the opposite direction as long as the catalyst remains effective (and there's no indication in the problem that the catalyst's effect changes over time in a non - monotonic way). Also, a catalyst that reduces the energy barrier is designed to have an effect on the reaction rate, so the option of no effect is incorrect.

Answer:

Rate of reaction increases.