Before, During and After Class Learning Cycle Activities CCLI 2009 Mechanism Example

Oklahoma State University

This is a sample Before Class Exploration on mechanisms in chemical reactions. To answer the questions on this BCE it is OK to use your textbook, but if you can answers the questions without it that is OK too.

Do not press the RETURN or ENTER key while you are answering these questions. Your browser will interpret either the same as clicking on the Submit key.

Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.


The BCE should be completed before class starts, for this BCE class has already met. It will not count towards your BCE total. NOTE: If class has not started and you receive this message, go ahead and do the BCE, I'll still count it.

First Name:

Last Name:

Laboratory Section:

To complete this BCE click on the Reaction link below. When you click on the link a new window will appear. Resize the window and position it on your screen so you can move between it and the BCE window.

Simulation

1. Once the simulation appears click on the Enable Reactions button and then the Resume button and allow the simulation to run. Describe what you observe happening in the sample region. Use some or all of the following terms in your description: atom, molecule, particle, collision, effective collision, speed, energy, reactant(s), product(s), and intermediate(s).

The Replay option allows you to slow down the motion in the Sample Region
and to replay portions of the reaction sequence. You can click on the Pause Button and using the forward or reverse arrows on the time index function, view the motion of the particles a step at a time. You can click the mouse on the Reset button located below the temperature scrollbar to return to the original conditions.

 


2. Click on the reset button and identify and record in Table I below, the number and kind of particles in the sample region.

Table I

Particle

Number

G

B

G2B

Click on the Enable Reactions button and then the Resume button and observe the interaction in the sample region until no further change is observed. Record in Table II below, the number and kind of particles in the sample region.

Table II

Particle

Number

G

B

G2B

3. What criteria did you use to determine when the reaction in the sample region was finished.

4. Write an overall balanced chemical equation that best describes the reaction you observed in the sample region.

5. Does the overall balanced chemical equation clearly describe the conversion of reactants to products. Briefly explain.

6. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

6. If there is one question you would like to have answered in lecture, what would that question be?