UCI Chem 131C Thermodynamics and Chemical Dynamics (Spring 2012)

Lec 23. Thermodynamics and Chemical Dynamics -- Lindemann-Hinshelwood Part I --

View the complete course: http://ocw.uci.edu/courses/chem_131c_thermodynamics_and_chemical_dynamics.html

Instructor: Reginald Penner, Ph.D.

License: Creative Commons BY-NC-SA

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Description: In Chemistry 131C, students will study how to calculate macroscopic chemical properties of systems. This course will build on the microscopic understanding (Chemical Physics) to reinforce and expand your understanding of the basic thermo-chemistry concepts from General Chemistry (Physical Chemistry.) We then go on to study how chemical reaction rates are measured and calculated from molecular properties. Topics covered include: Energy, entropy, and the thermodynamic potentials; Chemical equilibrium; and Chemical kinetics.

Thermodynamics and Chemical Dynamics (Chem 131C) is part of OpenChem: http://ocw.uci.edu/openchem/

This video is part of a 27-lecture undergraduate-level course titled "Thermodynamics and Chemical Dynamics" taught at UC Irvine by Professor Reginald M. Penner.

Recorded on May 30, 2012

Slide Information

00:06- Lindemann-Hinshelwood

01:22- Announcements

3:19- Today: Steady-State Approximation, Lindemann-Hinshelwood Mechanism

03:46- The Steady-State Approximation

07:58- Graph: Concentration, Time

08:25- Solve the Simplified Equations that Result

09:37- How Does This Compare with the Exact Solution?

10:25- How Well the Steady State Works- Graph of Concentration, Time

11:18- The Steady-State Approximation is Breaking Down

12:30- Example: Apply the Steady-State Approximation to the Following Reaction Mechanism

18:06- Simplifying Further

21:26- Two Limiting Experimentally Observed Rate Laws

24:40- Most Elementary Reactions are Either Unimolecular or Biomolecular

25:44- Biomolecular Reactions Have an Obvious Mechanism in the Gas Phase

26:17- Transition State Graph

26:42- But How Does a Unimolecular Reaction Occur?

27:06- Unomolecular Reactions- Isomerization

27:31- Unimolecular Reacions- Decomposition Reactions

28:05- How Does this Happen? The Lindemann-Hinshelwood Mechanism Provides an Explanation

30:10- Applying the Steady-Sate Approximation to the Lindemann-Hinshelwood Mechanism

31:10- The Strong Collision Assumption

33:35- Can We Apply the Steady-State Approximation to the Mechanism?

34:14- What Does it Predict?

37:26- What Does This Mean Mechanistically?

38:04- The Kinetics of Pressure-Dependent Reactions

41:19- We Can Write the LH Rate in This Form

43:29- Does it Work? Plot

44:09- It Doesn't Work So Well

45:44- Reactions Where a Pre-Equilibrium is Established

47:45- Test the Lindemann-Hinshelwood Mechanism for the Isomerization of Cyclopropane

49:02- The Data is Not Convincing- Plot

50:18- Use the Steady State Approximation Again

Required attribution: Penner, Reginald Thermodynamics and Chemical Dynamics 131C (UCI OpenCourseWare: University of California, Irvine), http://ocw.uci.edu/courses/chem_131c_thermodynamics_and_chemical_dynamics.html. [Access date]. License: Creative Commons Attribution-ShareAlike 3.0 United States License.