For a first - order reaction, the rate of reaction is `1.0xx10^(-2) mol L^(-1) s^(-1)` and the initial concentration of the reactant is 1 M. The half-life period for the reaction is

Options

A. `6.93xx10^(-3)s^(-1)`
B. `0.693 s^(-1)`
C. `69.3 s`
D. `0.693 s^(-1)`

Answer

C

Explanation

Consider a simple general first order reaction `Ararr`products
Differential rate law is
`Rate=k[A]`
or `k=("Rate")/([A])=(1.0xx10^(-2)molL^(-1)s^(-1))/(1.0molL^(-1))`
`k10^(-2)s^(-1)`
For a first order reaction, half is given as
`t_(1//2)=(0.693)/(10^(-2))s^(-1))`
`=0.693xx10^(2)s`
`=69.3s`