Unit 14: Chemical Kinetics: How fast does a reaction occur
Reading
BJU Chemistry: Ch. 14 "Chemical Kinetics"
Zumdahl Chemistry: Ch. 12 "Chemical Kinetics"
Topics
Labs
BJU Chemistry: Ch. 14 "Chemical Kinetics"
Zumdahl Chemistry: Ch. 12 "Chemical Kinetics"
Topics
- Energy diagrams
- Rate factors
- The rate formula
Labs
- "Reactions and Rates" PhET weblab
- Coca Cola Research Assignment
Below: Placing a gummy bear in potassium chlorate illustrates fast reaction kinetics. This is a fast 'oxidation' reaction... the candy provides the source of carbon, and the chlorate radical (ClO3 -) provides quick oxygen.
| 14._kinetics_lecture_notes_2022.docx |
Lecture outline
Thermodynamics (our previous topic) answers the question of whether a reaction will go forward or not. If the change in Gibbs Free Energy is negative, the reaction is favorable. However, we didn't discuss how FAST a reaction would occur - it might take years to go forward (the rusting of steel would be an example of a slow chemical reaction).
Kinetics (this topic) addresses the 'how fast' question. If a reaction proceeds at all, how quickly does it do so? A reaction might not have any commercial usefulness if it doesn't take place relatively quickly. Thus, the field of reaction kinetics is very important in any commercial, real-life setting.
- Reaction energy diagrams, activation energy, activation complex.
- How reaction rates are effected by concentration, temperature, surface area, and catalysts
- Reaction mechanisms, rate determining step.
- Developing the rate equation. Solving for the rate constant, 'k'.
- Reaction orders
Thermodynamics (our previous topic) answers the question of whether a reaction will go forward or not. If the change in Gibbs Free Energy is negative, the reaction is favorable. However, we didn't discuss how FAST a reaction would occur - it might take years to go forward (the rusting of steel would be an example of a slow chemical reaction).
Kinetics (this topic) addresses the 'how fast' question. If a reaction proceeds at all, how quickly does it do so? A reaction might not have any commercial usefulness if it doesn't take place relatively quickly. Thus, the field of reaction kinetics is very important in any commercial, real-life setting.
The concept of spontaneity:
- A reaction might be spontaneous, but proceed at a really slow rate. Example: rusting of iron.
- Thus, spontaneous does not necessarily mean "fast".
- On the other hand, non-spontaneous means a reaction won't go forward at all on its own. A non-spontaneous reaction needs help to get over the activation barrier. This needed "help" might be in the form of a lit match, increasing the temperature of the reactor, increasing the pressure, using a catalyst, and so on.
"Reactions and Rates" weblab
Lab handout with instructions is posted below. Upload your completed work to Canvas. The answer key is here to help you, BUT DO YOUR OWN WORK FIRST!! Then use the answer key to self-check your answers.
Lab handout with instructions is posted below. Upload your completed work to Canvas. The answer key is here to help you, BUT DO YOUR OWN WORK FIRST!! Then use the answer key to self-check your answers.
| reactions_and_rates_weblab__2021_.docx |
| reactions_and_rates_weblab__answer_key_.docx |
"The Chemistry of NASCAR"
This assignment is posted in Canvas in multiple choice format. The handout below is for background information.
This assignment is posted in Canvas in multiple choice format. The handout below is for background information.
| 14._the_chemistry_of_nascar.pdf |
Kinetics homework problems
This assignment is posted in Canvas with multiple-choice questions. Watch the accompanying help-video, below.
This assignment is posted in Canvas with multiple-choice questions. Watch the accompanying help-video, below.
The Coca-Cola research assignment (below) will require Internet research. Use search terms such as "digestion of sucrose", "digestion of carbohydrates", "metabolism of sucrose", etc. Also read the "Chemistry of Digestion" paper, below.
| 14._coca_cola_research_assignment.docx |
| chemistry_of_digestion_-_american_chemical_society.docx |