Jobs:
Recorders: record materials, results and any specific data you need to remember.
Manager: Make sure everyone follows procedure and works as a team.
Safety: Make sure everyone works safely, and that the environment is clean and tidy, before, during,
and after the experiment.
*Take notes for now. You will use them to type your lab report. Follow the format below to start
your lab report. Add a cover page with a Title, picture and proper heading (Name, date, grade, +JMJ)
Cleaning Pennies
I.
II.
III.
IV.
V.
Problem Statement: What cleans pennies best?
Introduction: (Answer the following questions in a paragraph/essay format and using
complete sentences. Do not write the questions or the numbers.)
1. What are pennies made of?
2. What is a chemical reaction?
3. How do we know a chemical reaction has happened?
4. What is the name of the reaction that happens when a metal reacts with oxygen?
5. Where can oxygen be found?
6. Recalling what you have studied in class, what objects can undergo oxidation? (Trees?
Rocks? Structures?)
7. Why do you think the pennies are dark in color?
8. Is cleaning pennies an example of a chemical reaction?
Hypothesis: What do you think will happen?
“If pennies are placed in different containers with water, water and salt, vinegar, and
vinegar mixed with salt then the pennies that are placed in the (choose a container
substance) will get cleaned the most, and the pennies that are placed in the (choose a
container substance) will get cleaned the least.
Materials:
Procedure:
1. Label the cups 1, 2, 3
2. In cup 1, put 60 ml of water.
3. In cup 2, put 60 ml of vinegar.
4. In cup 3, put 60 ml of water and 1 teaspoon of salt.
5. In cup 4, put 60 ml of vinegar and 1 teaspoon of salt.
6. Place half a penny in each of the solutions for 15 seconds. Record results for each.
7. Place 4 pennies in each of the solutions for 10-15 minutes. Record the time and the
results for each.
VIII. Analysis: (answer the following questions in a paragraph/essay format. Do not write the questions .)
1. Create a graph displaying the data from your experiment.
2. What is the effect of enzyme concentration on enzyme activity? How does enzyme activity change as
enzyme concentration decreases?
3. How does temperature affect the activity of catalase? Explain your observations by discussing the effect of
temperature on protein structure. Discuss both high and low temperature effects.
4. How does pH affect the activity of catalase? Consider both high and low pH and explain your observations
by discussing the effect of pH on protein structure.
5. Ectothermic organisms have body temperatures that vary with the temperature of their surroundings.
Discuss the effect this variation might have on the functioning of enzymes in these organisms. Suggest
some ways ectothermic organisms might cope with this problem.
6. Endothermic organisms retain a stable internal body temperature (homeostasis). Would the change in
seasons have any effect on the functioning of enzymes in these organisms? Explain your answer.
IX. Conclusion: (answer the following questions in a paragraph/essay format. Do not write the questions )
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What were you investigating?
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How can this experiment be improved OR in what way could you continue to study this problem
statement?
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What are some possible applications/uses of the experiment to the real world?
What is the answer to your problem statement?
Was your hypothesis supported by the data, or not? Explain.
Did you get any unexpected results? What possible explanations can you offer for any unexpected
findings?
Equation:
HC2H3O2 + NaCl ---> HCl + NaCH3O2
(vinegar) + (salt) ---> (hydrochloric acid) + (sodium acetate)
CuO + HCl ---> CuCl2 + H2O
copper(II) oxide + hydrochloric acid ---> copper(II) chloride