Average rate of reaction : From the concentrations of R at different times given below, calculate the average rate of the reaction :
`R rarr P`
During different intervals of time
`{:(t//s,0,5,10,20,30),(10^(3)xx[R]//mol L^(-1),160,80,40,10,2.5):}`
Strategy : Determine the difference in concentration, `Delta[R]` over different intervals of time. Divide `Delta[R]` by `Delta t` to determine the average reaction rate.

Explanation

Average reaction rate `= - (Delta[R])/(Delta t)`
`([R]_(1)xx10^(3))/(mol L^(-1)) ([R]_(2)xx10(3))/(mol L^(-1)) (t_(2))/(s) (t_(1))/(s) (r_(av)xx10^(3))/(mol L^(-1)s^(-1)) [=(-([R]_(2)-[R]_(1)xx10^(3)))/((t_(2)-t_(1)))]`
`{:(160,80,5,0, ,16),(80,40,10,5, ,8),(40,10,20,10, ,3),(10,2.5,30,20, ,0.75):}`