Question

For a first order reaction $A\to$ products, the rate of reaction at $\left[A\right]=0.2M$ is $1\times {10}^{-2}molli{t}^{-1}mi{n}^{-1}$. The half life period for the reaction is:

• A. 832 min
• B. 440 min
• C. 416 min
• D. 14 min

Answer 1

The correct option is D 14 min

For a first order reaction, $r=k\left[A\right]$

$k=\frac{{10}^{-2}}{0.2}$

Also,

$t_{1/2}=\frac{0.693}{k}=\frac{0.693\times 0.2}{{10}^{-2}}=13.86min=14min$