$2\mathrm{.}18.$ Show that the following scheme

$N_2{O}_5{}^{k_1}N{O}_2+N{O}_3^{**}$

$N{O}_3^{**}{k}_{3}N{O}^{**}+O_2$

$N{O}^{**}+N{O}_3^{**}{k}_{4}2N{O}_2$

proposed by R$.$ Ogg, J$.$ Chem. Phys$.,15,337(1947)$ is consistent with, and

can explain, the observed first$-$order decomposition of $N_2{O}_5.$