The rate constant of a reaction is `0.69 xx 10^(-1)` and the initial concentration is `0.2 "mol l"^(-1)`. The half-life period is

Options

A. `400 sec`
B. `600 sec`
C. `800 sec`
D. `1200 sec`

Answer

B

Explanation

The unit of rate constant shows that reaction is of first-order. For first-orde reaction, half life is independent of initial conc. of the reactant. Thus,
`t_(1//2) = (0.693)/(0.69 xx 10^(-1)) = (0.693 xx 60)/(0.69 xx 10^(-1)) = 600 sec`