An average reaction rate is calculated as the change in the concentration of reactants or products over a period of time in the course of the reaction. An instantaneous reaction rate is the rate at a particular moment in the reaction and is usually determined graphically, but it can also be calculated using calculus. The reaction of compound A forming compound B was studied and the following data were collected:

Time (s) [A] (M)
0 0.184
200 0.129
500 0.069
800 0.031
1200 0.019
1500 0.016

a. What is the average reaction rate between 0 and 1500 s?
b. What is the average reaction rate between 200 and 1200s ?
c. What is the instantaneous rate of the reaction at t=800s?