For a first-order reaction `A rarr B` the reaction rate at reactant concentration of `0.10 M` is found to be `2.0 xx 10^(-5) "mol" L^(-1) s^(-1)`. The half-life period of the reaction is

Options

A. 30 s
B. 220 s
C. 300 s
D. 347 s

Answer

D

Explanation

Given [A]=0.01 M
`"Rate"=2.0 xx 10^(-5) mol L^(-1) s^(-1)`
For a first order reaction
Rate=k[A]
`k=(2.0 xx 10^(-5))/([0.01])=2 xx 10^(-3)`
`t_(1 // 2)=(0.693)/(2 xx 10^(-3))=347` sec