For the first-order reaction `(C=C_(0)e^(-k_(1)^(t)))` and `T_(av)=k_(1)^(-1)`. After two average lives concentration of the reactant is reduced to :

Options

A. 0.25
B. 0.75
C. `(100)/(e )%`
D. `(100)/(e^(2))%`

Answer

D

Explanation

`C=C_(o) e^(-k_(1)t)" After "t=(2)/(k_(1))[1//k_(1)" is called average life"] rArr C=C_(o) e^(-2) =(C_(o))/(e^(2))=(100)/(e^(2))%`