How much time is requred for two - third completion of a first order reaction having, `K=5.48xx10^(-14)S^(-1)`?

Options

A. `2.01xx10^(11)s`
B. `2.01xx10^(13)s`
C. `8.08xx10^(13)s`
D. `16.04xx10^(11)s`

Answer

B

Explanation

Time required for two-third completion of a first order reaction,
`[A]_(0)=a,[A]=a-(2)/(3)a=(a)/(3)`
`t_(t//2)=(2.303)/(k)"log"([A]_(0))/([A])=(2.303)/(K)"log"(a)/(a/3)`
`=(2.303)/(K) "log"3`
`t(1//2)=(2.303xx0.4771)/(5.48xx10^(-14))=2.01xx10^(13)s`