The rate constant for a first order reaction is 60 s^(-1). How much time will it take to reduce the initial concentration of the reactant to its l/16^(th) value?

Explanation

For a first-order reaction:
Rate of a reaction= `k xx" molar concentration of the reactant"`.
(a) `:.` Initial rate = `k xx" initial concentration"=0.02xx2=0.04 mol//L^(-1)sec^(-1)`.
(b) Concentration of the reactant after 60 sec
`k=2.303//60log 2//"concentration"` after 60 s = 0.02.
`:.` Concentration of the reactant after 60 sec = 0.60 M.
`:.` Rate after 60 sec = `k xx" concentration of the reactant after 60 sec."= 0.02 xx 0.60`
`= 0.012 molL^(-1)sec^(-1)`