Half-life perood for a first order reaction is 10 min. How much time is needed to change the concentration of the reactant from 0.08 M to 0.01 M ?

Options

A. 10 min
B. 30 min
C. 20 min
D. 40 min

Explanation

`[A]/[A]_0=1/2^n`
`0.01/0.08= 1/2^n`
`1/8 = 1/2^3 = 1/2^n :.n = 3`
`t= n xx t_(1//2)= 3 xx 10= 30min`.