Answer:
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:
