Why does the reaction rate increase when a catalyst is added

The reaction rate increase when a catalyst is added "because it hike the reaction rate by lowering the activation energy for a reaction."

Explanation:

A catalyst can be a chemical or biological in nature but its role always remain same "to increase reaction rates and the method vary from other ways of hiking reaction rate". Its intention is to reduce the activation energy, so that a larger proportion of the particles has enough energy to react.

The activation energy for a reaction is minimized by catalyst by targeting type of orientation of the  the reacting particles for causing more effective collisions. It react with the reactants to generate an intermediate product requiring less energy to form the product.

i don't get what you mean

explanation:

answer; (c) a law code that provides believers with a set of pratical laws to regulate their daily lives