Alkylperoxynitrates (RO2NO2) can be assumed to decompose according to
the following mechanism:

RO2NO2 ? RO2+NO2, k1 forward, k2 backward
RO2+RO2 ?2RO+O2, k3
RO+NO2 ?RONO2, k4
Assuming that a sample of (RO2NO2) decomposes in a reactor and its
decay is observed. We desire to estimate k1 the rate of disappearance.
To analyze the system we assume that both RO2 and NO2 are in
pseudo-steady state and that [RO2] = [NO2].
Show that the observed first-order rate constant for RO2NO2 decay is
related to the fundamental rate constants of the system by:
kobs. =k1*{1-(k2/(2k3+k2))}