Answer:
B) It will decrease because fewer particles will have the required activation energy.
Step-by-step explanation:
Temperature is one of the important factors that affect the rate of a chemical reaction. An increase in the temperature of a reaction will cause the reactants to gain more kinetic energy and hence, reduce the energy required for reactants collision (start) to occur i.e. activation energy.
Note that, once the activation energy is reduced, the rate of reaction is increased. In this case, the temperature of a reaction vessel with liquid reactants is lowered to one-third (1/3) of the original temperature. Due to a reduction in the reaction's temperature, the rate of reaction will also decrease because fewer particles will have the required activation energy.