A catalyst increases the rate of reaction because it:
increases the activation energy
decreases the activation energy
decreases collision diameter
increases the temperature coefficient
The correct option is B decreases the activation energy The presence of a catalyst increases the reaction rate (in both forward and reverse reactions) by providing an alternative pathway with lower activation energy.
Activation energy is the minimum energy barrier which the reagents have to cross for the completion of the reaction. If the activation energy is lowered, more reactants can cross that barrier easily and so, the rate of reaction increases.