Question

The rate constant of reaction is $0.69\times {10}^{-1}mi{n}^{-1}$ and the initial concentration is $0.2$ mol $L^{-1}$. The half-life period is:

• A. $400sec$
• B. $600sec$
• C. $800sec$
• D. $1200sec$

Answer 1

Answer: (B)

$600sec$

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,

$t_{1/2}$=$\frac{0.693}{0.69\times {10}^{-1}}$=$\frac{0.693\times 60}{0.69\times {10}^{-1}}$=$600sec$