According to collision theory, what three factors govern the effect of temperature on the rate of a chemical reaction?

Collision theory states that the rate constant for a chemical reaction is composed

of three factors, (1) the absolute number of collisions, Z, between molecules; (2) The

fraction of collisions, f, with an energy greater than the activation energy; and (3) the

fraction of molecules, p, in which the molecules are in the correct orientation to react.

k = Zfp Equation 1

The absolute number of collisions, Z, increases with temperature. However, it has

been shown that at 25o

C, the increase in the number of collisions accompanying a 10o

C

increase in temperature accounts for only about 2% of the increase in the reaction rate.

Similarly, while it is important that molecules be in the proper orientation to react when

they collide, molecular orientation is independent of temperature. Thus it follows that the

major factor controlling reaction rates is the fraction, f, of molecules in the reaction

mixture with an energy greater than the activation energy. This factor, f, depends on the

absolute temperature. It has been shown that f is related to Ea by the following equation

Explanation: