Top-Rated Free Essay # Lab Penny Ante 2

Better Essays
1080 Words Grammar Plagiarism  Writing  Score Lab Penny Ante 2 Penny-Ante Equilibrium

Introduction
What is equilibrium? What happens to the amount of reactants and products when equilibri­um is reached? What if more reactants or products are added to a system already at equilibri­um? In this activity, pennies will be used as reactants and products in a reversible reaction to answer these questions and learn more about the fundamental nature of equilibrium.
Concepts
• Reversible reactions • Equilibrium
• Equilibrium constant • LeChatelier's principle
Materials
Small objects, such as pennies, pop-it beads, paper clips, bingo chips, etc., 60 Beakers or other large containers, 2
Safety Precautions
Although this activity is considered nonhazardous, observe all normal laboratory safety guidelines.
Overview of the Activity
1. Each member of the group chooses a defined role: (a) reactant, (b) product, (c) monitor, and (d) recorder.

2. Obtain a counted set of 60 small pennies. These will be used to represent reactants and products in a chemical reaction.

3. Obtain two containers to hold the pennies. Label one container R, for reactants, and the other container P, for products.

4. In Parts A-D, the pennies will be moved in a series of steps between containers R and P.

5. Read the discussion questions at the end of the instructions.
Procedure
Part A. What are the properties of a system at equilibrium?
1. Place 42 pennies in container R, none in container P.
2. In each transfer round, reactant will move one-third of the pennies from container R to P, and product will move one-quarter of the pennies from container P to R. Note: In deciding how many pennies to move, round all calculations down to the nearest whole number.
3. The monitor checks the number of pennies to be moved and gives permission for the actual "reactions" to take place.
4. The recorder constructs a suitable data table and records results. The following informa­tion is needed: the initial number of pennies in R and P, the number of pennies that are moved out of each, and the final number of pennies in R and P after the pennies have "reacted."
5. In the first round, reactant counts out 14 pennies (one-third of 42) to move. Product cal­culates that one-quarter of zero is zero and does not move any pennies in the first round.
6. Repeat Steps 2-5 and carry out a second round of penny "reactions" in both directions between R and P. Remember that one-third of the R pennies but only one-fourth of the P pennies will react in each round.
7. Continue moving pennies back and forth until no further changes are observed in the number of reactants and products.
8. Calculate the ratio of reactants and products (P/R) and enter the result in the data table.
Part B. Does the position of equilibrium depend on the initial number of reactants?
9. Place 60 pennies in container R, none in container P.
10. Repeat the process followed in Part A to move the pennies between R and P until no further changes are observed in the number of reactants and products. Keep the fractions of pennies that react the same as in Part A: 1/3 of R, 1/4 of P.
11. Calculate the ratio of reactants and products (PIR) and enter the result in the data table.
Part C. Does the position of equilibrium depend on the starting point?
12. Place 42 pennies in container P, none in container R.
13. Repeat the process followed in Part A to move the pennies between R and P until no fur­ther changes are observed in the number of reactants and products. Keep the fractions of pennies that react the same as in Part A: 1/3 of R, 1/4 of P.
14. Calculate the ratio of reactants and products (P/R) and enter the result in the data table.
Part D. What happens when more reactants are added to a system at equilibrium?
15. Starting with the equilibrium number of pennies in R and P obtained at the end of Part C, (18 R & 24 P) add 18 extra pennies to container R.
16. Repeat the process followed in Part A to move the pennies between R and P until no fur­ther changes are observed in the number of reactants and products. Keep the fractions of pennies that react the same as in Part A: 1/3 of R, 1/4 of P.
17. Calculate the ratio of reactants and products (P/ R) and enter the result in the data table.
Data Table
Use the following table to record the results in each part of the activity.
Transfer Round*

Reactant

Product

P/R at Equilibrium

Number of Pennies (initial)

Number of Pennies Moved

Number of Pennies (final)

Number of Pennies (initial)

Number of Pennies Moved

Number of Pennies (final)

0

1

2

3

4

5

6

*A "zero" round (before any reaction begins) is included to use as a starting point when graphing the results, if desired.
Discussion Questions
1. Based on the results obtained in Part A, describe the changes observed in the number of pennies in R and P over the course of the "reaction."
2. Write a definition of equilibrium based on the answer to Question #1.
3. Compare the results obtained in Parts A and B. (a) Does the P/R ratio depend on the ini­tial number of reactants? (b) Predict the number of pennies that would be present in con­tainers R and P at equilibrium if you started with 100 pennies in R, none in P.
4. Compare the results obtained in Parts A and C. The PIR ratio may be called the "equilibri­um constant" for the penny reactions. What does this mean?
5. Compare the results obtained in Parts A, B, and D. (a) What happened when the initial equilibrium condition was changed? (b) Predict the number of pennies that would be present in containers R and P at equilibrium if 18 extra pennies had been added to P rather than to R in Part D.
6. In this activity, the reactions between R and P appeared to stop when no further changes were observed. Do chemical reactions actually stop when this happens? Explain.
7. Chemical equilibrium is best described as a dynamic condition. What does this mean?
8. Graph the results obtained in Parts A and C. Plot the final number of pennies in containers R and P versus the transfer round. Use different colors for R and P.

## You May Also Find These Documents Helpful

• Good Essays

INTRODUCTION: Before 1982 the US penny was made of pure copper. Because of the high cost of copper, the US government changed the composition of the penny. As of 1982, pennies have been made of mostly zinc, with a thin copper layer on the outside. The first step in finding the % of copper is to make solution out of the penny. In other words “liquefy” the penny. To differentiate between the copper and zinc; zinc is clear and copper turns blue. During this lab, we will be making several standard solutions of this penny solution. To find out each solutions concentration, we will find its molarity by using the formula:…

• 916 Words
• 5 Pages
Good Essays
• Satisfactory Essays

synthesis Conclusion: 1. Write a balanced equation for each reaction observed in this lab. (10 points total, 2 points each)…

• 340 Words
• 2 Pages
Satisfactory Essays
• Good Essays

4. One member will act as the enzyme (paperase), one member will be the timer, one member will be the announcer and one member will be the recorder and will write down the number of molecules ripped by each time interval on the data worksheets.…

• 863 Words
• 4 Pages
Good Essays
• Good Essays

6. While wearing gloves, carefully pour 50 mL 3M HCl into the beaker. 7. Place your labeled beaker under the fume hood to react. Observe the effect the acid has on the copper outside of the penny.…

• 623 Words
• 3 Pages
Good Essays
• Good Essays

Background information The experiment is to observe a variety of chemical reactions and to identify patterns in the observation of reactants into products. The properties of the reactions will be analyzed to classify the chemical reactions into different groups.…

• 2467 Words
• 10 Pages
Good Essays
• Satisfactory Essays

1. View the three scenarios listed below. You must observe and analyze these as part of the lab.…

• 738 Words
• 3 Pages
Satisfactory Essays
• Good Essays

• 522 Words
• 3 Pages
Good Essays
• Satisfactory Essays

Part II 40:40 Round Reactants Products 1 35 45 2 33 47 3 32 48…

• 782 Words
• 4 Pages
Satisfactory Essays
• Satisfactory Essays

15 16 24 Calculations: Calculate the ratio of products to reactants for each part of the lab. Show the set up as well as the simplified ratio. (2 points for each calculation, or 6 points total)…

• 430 Words
• 6 Pages
Satisfactory Essays
• Powerful Essays

Objectives: The lab experiment will consist of oxidation-reduction and double displacement reactions as well as titration techniques. All these components will be used in order to determine the percent composition of pennies. In conducting redox and double displacement we are able to analyze a penny and figure out the chemical composition of the product. The experiment entails careful observations and recording of evidence for a chemical reaction. In this experiment observe gases being produced, the forming of precipitation and color changes.…

• 754 Words
• 3 Pages
Powerful Essays
• Powerful Essays

5. When the reaction is complete, record the mass of the bag and its contents in Table 1.…

• 712 Words
• 3 Pages
Powerful Essays
• Satisfactory Essays

5. Follow the instructions in Step 3 for a total of 10 rounds. 6. At the end of 10 rounds, calculate the ratio (ratio = P/R) of products to reactants.…

• 826 Words
• 4 Pages
Satisfactory Essays
• Satisfactory Essays

* Paper towels * Lab review sheet * Pencil * Pipette -Procedure First we picked who would drop the water onto the penny. We did this to ensure that the drops were even in size. We then carefully dropped water from the dropper onto the head side of the penny while counting the number of drops.…

• 346 Words
• 2 Pages
Satisfactory Essays
• Satisfactory Essays

When you turn on the battery, bubbling happens. Data and Observations: Complete a data table that includes a prediction of reaction type, observations, and identification of reaction type for each reaction in the lab. (10 points)…

• 458 Words
• 2 Pages
Satisfactory Essays
• Satisfactory Essays

For this assignment you will research one of the equilibrium systems below, or one approved by your instructor, and prepare a presentation describing the system.…

• 315 Words
• 2 Pages
Satisfactory Essays