Which statement describes chemical reactions that take place at different rates?
a. one reaction produces more products than the other.
b. one reaction begins with more reactants than the other.
c. one reaction takes place in less time than the other.
d. one reaction involves a color change and the other does not.

c.  One reaction takes place in less time than the other.

I think the correct answer among the choices listed above is option C. Chemical reactions that take place at different rates can be described as one reaction taking place in less time than the other. Reaction rates has units of mol/L min. It is comparable to speed.

The answer is a.

Explanation: