Question

The rate constant of a reaction is `0.69 xx 10^(-1) "min"^(-1)` and the initial concentration is `0.2` mol `l^(-1)` . The half - life period is
A. 400 sec
B. 600 sec
C. 800 sec
D. 1200 sec

Answer 1

Correct Answer - b
The unit of rate constant shows that reaction is of first order . For first order 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.