For a first order reaction `A rarrB` , the reaction rate at reactant concentration of 0.01 M is found to be `2.0xx10^(-5) "mol L"^(-1) s^(-1)`. The half life period of the reaction is

Options

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

Answer

d

Explanation

R = k[A]
`2 xx 10^(-5) = k xx 10^(-2)`
`k = 2 xx 10^(-3) sec^(-1)`
`t_(1//2) = (0.693)/(k) = (0.693)/(2 xx 10^(-3)) = (693)/(2) = 347` sec .