Equilibrium Case
Number of Pages: 3 (Double Spaced)
Number of sources: 3
Writing Style: APA
Type of document: Lab Report
Academic Level:Undergraduate
Category: Chemistry
CHEMICAL KINETICS
Assignment Overview
Note: You must install Adobe Shockwave Player and Quicktime onto your computer in order to view these videos and tutorials. They are available for free online at http://www.adobe.com/products/shockwaveplayer.html & https://support.apple.com/downloads/quicktime). Google Chrome browser does NOT work for the Pearson links; please use Mozilla Firefox in this case.
In the following activity, you will be working with an equilibrium simulation activity and completing the questions on the lab activity below.
Equilibrium
When a reversible reaction reaches equilibrium, the amount or concentration of products and reactants level off due to the fact that the forward reaction changes reactants into products at the same rate that the reverse reaction changes products into reactants.
Stress
When a system at equilibrium is stressed, the chemicals in the closed system respond to the stress and make either more products or reactants. Once again, the concentrations will level off and a new equilibrium with different concentrations will be established.
Shift
The term shift simply indicates the direction (forward or reverse) of a reaction that increases in rate when a stress is applied. For example, if a reaction shifts to the right as a result of a stress being applied, the forward reaction rate increases and the concentration of the products increase. Logically, the concentration of the reactants must decrease.
What are we doing in the following exercise?
In this activity, your job is to examine how stress (temperature, pressure, and concentration) causes a system at equilibrium to shift and establish a new equilibrium.
You should hypothesize about which direction the equilibrium will shift after you apply the stress.
Keep careful track of what’s going on so that you can look back and discuss what happened.
In this video, Paul Andersen defines the rate of a reaction as the number of reactants that are consumed during a given period of time. The rate of the reaction can be affected by the type of reaction as well as the concentration, pressure, temperature and surface area. Be sure to watch the entire video to watch his discussion of the PhET video you will be working with in this case assignment.
Rate of Reactions. Bozeman Science. Accessed at https://www.youtube.com/watch?v=6mAqX31RRJU on June 8, 2017.
Learn more about Le Chatelier’s Principle in the following video:
Le Chatelier’s Principle. FuseSchool. Accessed at https://www.youtube.com/watch?v=7zuUV455zFs on June 8, 2017.
For this Case study, you will be completing the word doc assignment below on Equilibrium. Complete the interactive simulation (link provided in document) then answer the questions contained in the word document below.
Once you have completed the answers contained with the Equilibrium assignment below, save the word document and upload the final version to the Case Assignment dropbox area of Module 3.
Equilibrium Case
Exploring Equilibrium
Login to the computer and open a web browser. Go to https://phet.colorado.edu/en/simulation/legacy/reactions-and-rates . Open or download the simulation.
When the simulation is open, click on the “Many Collisions” tab.
Look at the screen and observe everything you can find out about the reaction pictured, A + BC ( AB + C.
Click “Show stopwatch”.
Turn on the bar chart.
Let each experiment run for 600 seconds to allow enough time for equilibrium to be established.
1) Predict what will happen when 50 A’s are added to the box and 50 BC’s are added.
2) In the box labeled “current amounts,” enter 50 for A and 50 for BC.
a) Was your prediction correct? Describe and explain any differences.
b) Describe the nature of dynamic equilibrium when small numbers of particles (such as 50, as compared to 6.022 x 1023) are present.
3) Predict what will happen when the temperature is raised so it is NOT above the activation energy max but IS above the energy level of the products.
4) Raise the temperature as described. Did your prediction come true? Describe and explain any differences.
5) Predict what will happen when the temperature is raised so it is above the activation energy max.
6) Raise the temperature as described. Again, was your prediction correct? Describe and explain any differences.
7) What did you notice about the rate at which reactants/products fluctuated between the three different temperatures? If you didn’t notice anything, hit “reset all” and test it again.
8) Did temperature affect equilibrium position? Did it affect it in the way you expected? Explain.
9) Did temperature affect reaction rate? Did it affect it in the way you expected? Explain.
Le Châtelier’s Principle
Instructions: Now choose the “Rate Experiments” tab. As you play with the sim, answer the questions below.
11) In the previous lab (“Exploring Equilibrium”) you investigated the effect of temperature on equilibrium position; you may have found that temperature did not affect equilibrium in quite the way you expected. Add 80 A’s and 80 BC’s to the box for the first reaction and begin the experiment; let the reactions run until equilibrium is reached. Knowing Le Châtelier’s Prinicple, now predict and explain what will happen to the equilibrium position when the temperature is raised and lowered. Then test your ideas using the sim and explain your observations. Give numerical data to support your claims.