Nitrogen pentoxide decomposes according to equation :
`2N_(2)O_(5)(g) rarr 4NO_(2)(g) + O_(2)(g)`.
This first order reaction was allowed to proceed at `40^(@)C` and the data below were collected :

(a) Calculate the rate constant. Include units with your answer.
(b) What will be the concentration of `N_(2)O_(5)` after 100 minutes ?
(c ) Calculate the initial rate of reaction ?

Explanation

(a) `k = (2.303)/(t)log.(A_(0))/([A])`
`k = (2.303)/(20 min)log.(0.400)/(0.289)`
`k = 0.0163 min^(-1)`
(b) `k = (2.303)/(t)log.(A_(0))/([A])`
`=0.0163 - (2.303)/(100)log.(0.400)/([A])`
`[A] = 0.078 M`
(c ) Initial rate R `= k[N_(2)O_(5)]`
`= 0.0163 min^(-1) xx (0.400 M)`
`=0.00652 M min^(-1)`