Describe how the four major factors influence the rate of a
chemical reaction.
(a) concentration of reactants
As the concentration of reactants increases, the number of
collisions per unit time  ---Select--- increase decrease
, and the reaction rate  ---Select--- increases decreases
.
(b) frequency factor
The frequency factor is a measure of molecular obstruction. More
obstruction in a molecule leads to a  ---Select--- higher
lower frequency factor, which  ---Select--- increases
decreases the rate constant, resulting in  ---Select---
an increased a decreased overall reaction rate.
(c)...