Question

The rate of a reaction can be observed by measuring the change in the amount of a reactant over time, as given in the graph below. How does the rate of a reaction change with time and how does the collision theory explain this change?

Answer 1

Collision theory in a nutshell:

at the start of the reaction, there are lots of reactant molecules flying around, banging into each other, possibly hard enough to cause a reaction to take place. as the reaction proceeds, the amount of reactant decreases, so the number of collisions decreases, so the number of "effective" collisions decreases, so the change in concentration over time decreases as well.

Answer 2

Thanks (: