Question

Calculate the half-life of a first order reaction from their rate constants given below:

$200s^{-1}$

$2mi{n}^{-1}$

$4y{r}^{-1}$

Answer 1

Half-life period for first order reaction
$t_{\frac{1}{2}}=\frac{0.693}{k}$
$t_{\frac{1}{2}}=\frac{0.693}{200s^{-1}}=0.346\times {10}^{-2}s=3.46\times {10}^{-3}s$

Half-life period for first order reaction
$t_{\frac{1}{2}}=\frac{0.693}{k}$
$t_{\frac{1}{2}}=\frac{0.693}{2mi{n}^{-1}}=0.346min=3.46\times {10}^{-1}min$

Half-life period for first order reaction
$t_{\frac{1}{2}}=\frac{0.693}{k}$
$t_{\frac{1}{2}}=\frac{0.693}{4y{r}^{-1}}=0.173yr=1.73\times {10}^{-1}yr$