Question

For a reaction $A → 2B + C$ the half lives are 100 s and 50 s when the concentration of reactant A is 0.5 and 1.0 mol L–1, respectively. The order of the reaction is ______ .(Nearest integer)

Answer 1

$t_{\frac 12}∝\frac {1}{(α_0)^{n−1}}$

$t_{\frac 12}=100 sec α_0=0.5$

$t\frac 12=50 sec α_0=1$

$\frac {100}{50}=(\frac {1}{0.5})^{n−1}$
$(2)=(2)^{n−1}$
$n–1 = 1$
$n = 2$

So, the order of the reaction is $2$.