1. Education Research Survey
As always…
Lon-Capa assignments
Lecture videos
Textbook
Read
Do text homework
Education Research Survey

2. Exam III
Thursday, December 6, 7:00-9:00 pm; rooms are on the website (same as Exam II).
Conflict: (12/6) 4:30-6:30 pm in 219 Greg; sign up in 1026 Chem Annex starting Friday
Conflict with conflict? me right away.
Review sessions: 1024 Chem Annex, 6-8 pm
Monday, December 3
Tuesday, December 4

3. Remaining Lectures Wednesday, December 5: review for Exam 3.
Friday, December 7: go over Exam 3.
Monday, December 10: review the semester; discuss the final exam; revisit demonstrations.
Wednesday, December 12: no lecture; office hours in 3014 Chem Annex from 10am-12pm.

5. Chapter 15

6. Chapter 15 #91

7. Previous Exam Question
Consider the “Magic Genie” demonstration, in which hydrogen peroxide decomposed to water and oxygen gas with the aid of a catalyst. The activation energy of this reaction (uncatalyzed) is 70.0 kJ/mol. We added a catalyst that lowered the activation energy (at 20C) to 42 kJ/mol.
Theoretically, to what temperature (C) would we have to heat the hydrogen peroxide solution so that the rate of the uncatalyzed reaction was equal to the rate of the catalyzed reaction? Assume the frequency factor A to be constant.

8. Previous Exam Question (pt 1)
Pure N2O was placed in a rigid vessel and allowed to decompose. The following data were collected in an experiment at a constant temperature of 298K. Assume the rate of the reverse reaction is negligent in this problem.
2N2O(g)  2N2(g) + O2(g) rate = –d[N2O]/dt
Determine the rate law for
the reaction including the order
of the reaction and the value
(with units) for the rate constant.
Time (min)
Ptotal (atm)
1.000
10.00
1.125
20.00
1.218
30.00
1.288
40.00
1.341
50.00
1.381

9. Previous Exam Question (pt 2)
Pure N2O was placed in a rigid vessel and allowed to decompose. The following data were collected in an experiment at a constant temperature of 298K. Assume the rate of the reverse reaction is negligent in this problem.
2N2O(g)  2N2(g) + O2(g) rate = –d[N2O]/dt
Determine the partial pressure
of N2(g) at min.
Time (min)
Ptotal (atm)
1.000
10.00
1.125
20.00
1.218
30.00
1.288
40.00
1.341
50.00
1.381

10. Previous Exam Question (pt 3)
Pure N2O was placed in a rigid vessel and allowed to decompose. The following data were collected in an experiment at a constant temperature of 298K. Assume the rate of the reverse reaction is negligent in this problem.
2N2O(g)  2N2(g) + O2(g) rate = –d[N2O]/dt
The reaction is carried out again at
303K. The first half-life is noted to
be at 4.58 min. Determine the
activation energy of the reaction.
Time (min)
Ptotal (atm)
1.000
10.00
1.125
20.00
1.218
30.00
1.288
40.00
1.341
50.00
1.381

11. Previous Exam Question (pt 4)
The formula of the reactant, N2O, doesn’t tell us if the skeletal structure is N-O-N or N-N-O, nor does it tell us if there is a best Lewis structure.
Your goal is to find the best Lewis structure for the compound, using formal charge as the primary basis. Justify your answer completely.

12. Previous Exam Question (pt 5)
Using the bond energies below and your answers to parts 1, 3, and 4, develop a mechanism for the reaction and support your answer.
2N2O(g)  2N2(g) + O2(g) rate = –d[N2O]/dt
Bond
Bond Energy (kJ/mol)
N–O
201
N=O
607
N=N
418
N≡O
941