a

Question Content Area Using collision theory, indicate why each of the following factors influences the rate of a reaction. Temperature of reactants (Select all that apply.) As the temperature increases, a smaller fraction of the collisions has enough kinetic energy to reach the activation energy. The number of collisions per second decreases with an increase in the temperature of a system. The number of collisions per second increases with an increase in the temperature of a system. An increase in the temperature of a system results in a decrease in the average speed of the reacting molecules movement. As the temperature increases, a larger fraction of the collisions has enough kinetic energy to reach the activation energy. An increase in the temperature of a system results in an increase in the average kinetic energy (the average speed) of the reacting molecules.

b

Question Content Area Presence of a catalyst (Select all that apply.) A catalyst increases the overall number of molecules in the system, and thus it increases the number of their collisions. A catalyst affects the molecular orientation. A catalyst increases the rate of reaction. A catalyst raises the activation energy. A catalyst slows down a reaction. A catalyst lowers the activation energy.