QUESTION 4 [20 POINTS]: The combustion of carbon monoxide in moist air has been studied
(Fourteenth Symposium on Combustion, The Combustion Institute, Pittsburgh, PA, p 987, 1972.)
in an isothermal batch reactor with the following global rate expression:
CO + \frac{1}{2}O_2 \overset{k_f}{\underset{k_r}{\rightleftharpoons}} CO_2,
where the forward and reverse reaction rates are expressed as
Forward rate = $-k_f[CO][H_2O]^{0.5}[O_2]^{0.25}$
Reverse rate = $-k_r[CO_2]$,
(1)
(2)
where
$k_f = 2.24 \cdot 10^{12} \left(\frac{kmol}{m^3}\right)^{-0.75} \left(\frac{1}{s}\right) \exp\left[\frac{-1.674 \cdot 10^8 (J/kmol)}{R_uT(K)}\right]$
$k_r = 5.0 \cdot 10^8 \left(\frac{1}{s}\right) \exp\left[\frac{-1.674 \cdot 10^8 (J/kmol)}{R_uT(K)}\right]$.
where the brackets represent concentration ie. [CO] is the concentration of our basis CO. Note
from the proposed mechanism above, that water (H?O) is really acting as a catalyst (it is not
consumed or generated in the reaction) and you are interested in seeing how the presence of
water changes the reaction. The condition are T=1000K (isothermal operation) and P= 1 atm.
Question 4a) Noting that the net rate of reaction, at any time, is expressed as the forward minus
reverse rates: what is the net rate of reaction at any time?
