Friday, Sept. 6th: “A” Day
Monday, Sept. 9th: “B” Day
Agenda
Density Activity
Homework Questions/Collect (Pg. 19: 1-11)
Section 1.2 Quiz: “Describing Matter”
Lab Write-Up/Discussion: “Counterfeit Pennies”
Reading/Writing Assignment
We will be in the lab next class
period – be sure to dress appropriately!
What is happening here?
Observe the two cans of pop in the tank.
You can come up for a closer look if you want…
Take a few minutes to write a paragraph that
scientifically explains what you think is
happening.
Homework
Pg. 19: #1-11
Questions?
Collect
Section 1.2 Quiz
“Describing Matter”
You may work with your 3:00 partner on the
quiz.
You will need a calculator.
You MAY use your guided notes and your book.
When you’re finished, turn it
in and pick up your lab folder…
Counterfeit Penny Lab
Mr. Vance received this memo at the High
School and forwarded it to the Chemistry
Department…..
S E C R E T
S E R V I C E
Secret Service Directive #1456
Date: August 1, 2013
To: Department of Chemistry
Morrison High School
Subject: Counterfeit coinage
Over the years, we have eliminated most counterfeiting operations in the United States. The
Secret Service has confiscated illegal equipment, and the paper currency was changed to
make counterfeiting more difficult
However, counterfeiting of coins has increased because coins are easy to reproduce but hard
to trace. Counterfeit pennies made in the 1970’s and 1980’s were produced by
substituting less expensive materials. Such substitutions can be detected by measuring
densities. Samples are enclosed for you to analyze.
Your task is to identify the year that the counterfeit coins entered the marketplace. Include a
hypothesis of which metal was used in the coins.
We look forward to your quick investigation and response.
Lab: “Counterfeit Pennies”
Update the table of contents in your lab folder
with this lab.
 “Counterfeit Pennies” should be lab #2 in
your lab folder.
(#1 was “Lab Techniques” )
Lab: “Counterfeit Pennies”
This lab is not a “cookie cutter” lab and
doesn’t list the purpose, materials, or even
the procedure.
With your 3:00 partner, think of an
experiment you could run to see if the pennies
that you have are pure copper, or not…
Hint: What did I do to see if the necklace that
I “found” was pure silver?
Lab: “Counterfeit Pennies”
Things to think about….
How many pennies should you use? Why?
Are there any pennies you shouldn’t use? Why?
Lab Write-Up: “Counterfeit Pennies”
When you’ve come up with a plan, check it
with me, and then begin your lab write-up:
Title:
Purpose:
Hypothesis:
Materials:
Procedure:
Reflection Statement:
Lab Write-Up: “Counterfeit Pennies”
After your reflection statement, include a data
table that looks like this:
Data Table #1
Year
Total Mass Volume
Total
Change Density
of Pennies of Water Volume
in
(g/mL)
Used
to Start of Water Volume
(g)
(mL)
+ Pennies of Water
(mL)
(mL)
Density Calculations
You will use water displacement to find the
density for each year you test.
Remember, the density formula:
Mass of pennies used (g)
CHANGE in volume (mL)
Lab Write-Up: “Counterfeit Pennies”
After conducting the lab, the whole class will
compile their data to create another table:
Data Table #2
Year Density
Note: you
(g/mL)
will need a
lot more
lines than
shown
here…
Lab Write-Up: “Counterfeit Pennies”
As part of your analysis, you will construct a
graph with year on the x-axis and density on
the y-axis using the data table created by the
whole class.
Title of Graph
Density
(g/mL)
Year
From this graph, you should be able to
determine the year that the pennies changed
composition.
Lab Write-Up: “Counterfeit Pennies”
Conclusion Questions
(Complete Sentences!)
1. What measurements are necessary to determine density?
2. Based you your graph, in what year did the counterfeit coins
appear?
3. Using Table A-5 in the back of your textbook (pg 829-830),
hypothesize which metal was used in the counterfeit coins.
4. How would mass measurements be affected if the pennies
were still wet from volume measurements?
5. What do you think is the biggest source of error in this
experiment? How could you minimize these errors in future
trials?
Reading/Writing Assignment
“5 Tanning Myths”
I recently found this article in the paper and
thought it was interesting and worthwhile to
share.
Read the article “5 Tanning Myths” and write a
reflection, using the rubric as a guide.
Respond critically to the article and be sure to
follow the rubric for full points.
Looking Ahead
Remember, we will be in the lab next time. Be
sure to dress appropriately!