Studies of combustion reactions depend on knowing the concentrations of H atoms and HO radicals.
Measurements on a flow
using EPR for the detection of radicals gave information on the reactions
(J.N. Bradley, W. Hack, K. Hoyermann, and H.G. Wagner,
J. Chem. Soc. Faraday Trans.
I, 1889 (1973)). Using
initial H atom and NO
concentrations of 4.5 × 10
and 5.6 × 10
, respectively, compute and plot
curves showing the O, O
, and OH concentrations as a function of time in the range 0–10 ns.
In a flow study of the reaction between O atoms and Cl
(J.N. Bradley, D.A. Whytock, and T.A. Zaleski,
Chem. Soc. Faraday Trans.
I, 1251 (1973)) at high chlorine
, plots of ln [O]
/[O] against distances
the flow tube,where [O]
is the oxygen concentration at zero chlorine
, gave straight lines. Given the flow
velocity as 6.66 m s
and the data below, find the rate coefficient for the reaction O + Cl
ClO + Cl.
= 3.3 10
] = 2.54 × 10
= 1.70 Torr.
J.D. Chapple-Sokol, C.J. Giunta, and R.G. Gordon (
J. Electrochem. Soc.
, 2993 (1989)) proposed the
following radical chain mechanism for the initial stages of the gas-phase
of silane by nitrous oxide:
Label each step with its role in the chain. Use the
to show that this mechanism predicts
are in some sense small):
The water formation reaction has been studied many times and continues to be of interest. Despite the many
studies there is not uniform agreement on the mechanism. But as explosions are known to occur at certain critical
values of the
,any proposed mechanism to be considered plausible must be consistent with the existence of
these critical explosion limits. One such plausible mechanism is that of Example 23.2. Another is the following: