This preview shows page 1. Sign up to view the full content.
Unformatted text preview: at higher temperatures the rate is substantially larger. (10 points) +5 for stating that faster rates were expected for higher temps
+5 for discussing why (mentioning activation energy, area under the curve, etc) Side 5 of 9 2014 Ch 1b Final Exam SOLUTIONS 4. (45 points) The gas phase homogeneous oxidation of nitrogen monoxide to nitrogen dioxide,
2NO + O2
is known to have a form of third-order kinetics, which suggests the reaction is elementary as written, at least for low partial pressures of the nitrogen
oxides. The proposed reaction mechanism for this oxidation is the following:
NO + O2
NO3 + NO
a) NO3 , k1 = forward rxn, k–1 = backward rxn k2NO2 , k2 = (forward) reaction rate constant
2 Derive a general consumption rate for NO, rNO, in terms of measurable quantities in the scheme outlined above, treating NO3 as a reactive
intermediate. (40 points total: 10 for setting up rNO, 10 for the correct steady-‐state approximation on r NO3, 10 for solving for [NO3] and plugging into rNO, 10 for correct final answer) b) From your answer in part (a), what conditions must hold in order for third-order kinetics to be observed? (5 points, -...
View Full Document
- Spring '13
- Organic chemistry