Question

For the decomposition of azomethane.
$CH _3 N _2 CH _3( g ) \rightarrow CH _3 CH _3( g )+ N _2( g )$ a first order reaction, the variation in partial pressure with time at $600 \,K$ is given as

The half life of the reaction is ______ $\times 10^{-5} s$
[Nearest integer]

Answer 1

For first order reaction
$ k =\frac{1}{ t } \ln \left(\frac{ P _0}{ P }\right) $
$ \ln \left(\frac{ P _0}{ P }\right)= kt$
$ t _{1 / 2}=\frac{\ln 2}{ k }=\frac{0.693}{3.465 \times 10^4}=2 \times 10^{-5}$