If the activation energy required for a chemical reaction were reduced, what would happen to the rate of the reaction?
the rate would increase.
the rate would decrease.
the rate would remain the same.
the rate would go up and down.

The rate would increase.

Explanation:

Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.

A chemical reaction which involves lower activation energy, means more molecules will gain sufficient energy to cross the energy barrier, thus  effective collisions increase and more products will be formed and hence the rate of reaction would increase.

The effect of catalyst on activation energy is shown in the image below:

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.