Class Notes regarding writing a lab report for the
Measuring Densities of Pennies Lab
THIS IS PARTIAL HELP ONLY. FOLLOW “How to Write a Lab Report utilizing the
Scientific Method” for specific lab format.
[TOTAL 50 Points]
[1] COVER SHEET:
1. Name
2. Date
3. Period
4. Title of Laboratory Experiment
5. Names of All Lab Partners
PRE-LAB:
[1] Purpose – (State the Problem)
Student EX: Find the density of pennies before and after 1982.
[5] Theory/ Introduction – (Gather Information/Background Information)
In this experiment pennies minted before and after 1982 will be examined because they
were made from different materials. . . . Include and expound on the information from the
“Introduction” in the lab handout. Look up the materials and densities of pennies minted before (1)
and after (1) 1982. Must also include information regarding: (1) Density is a derived unit = mass/
volume (D=m/v). (1) Mass is the amount of matter in an object. (1)Volume is the amount of space
taken up by an object. Density is a physical characteristic and may be used to determine a substance.
[2] Hypothesis – (Form the hypothesis)
Must propose (1) the density and material of pre- and post-1982 pennies with justification
(1).
LAB: (test the hypothesis) NEVER erase or white out. Cross out errors with a SINGLE LINE ONLY.
[3] physically came prepared and performed lab safely.
[1] Materials – Remember to correct the 50 mL with the 100 mL graduated cylinder.
[2] Safety – CAUTION glassware – use plastic safety ring at top of graduated cylinder neck, wear
closed toes shoes
[2] Procedure – May follow the lab handout but make any corrections regarding what was actually
done in lab.
[2] Observations/ Data – Include the actual lab handout written on in lab and the quantitative table
of measurements done in lab. Describe the pennies qualitatively.
POST-LAB:
[5] Chemical Equations/ Calculations / Problems – (Analyze the data)
 [1] Show calculation for obtaining net volume.
 [2] Show calculations for 2 sets of 5 trials for density, and average density for each set (preand post-1982 pennies)
 [2] Show calculations for 2 sets of 5 trials for % error, and average % error for
each set (pre- and post-1982 pennies)
[5] Graphs/ Charts – (Analyze the data)
* Follow instructions for #3 of the handout exactly.
* To find the slope of the line for #4 of the handout, use the following equation:
slope = m =
y2 - y1 = rise
x2 – x1 = run
Pick points (x2, y2) and (x1, y1) from the 2 points closest to your best-fit line on your graph.
Hoyumpa, Sept. 10, 2015
[10] Discussion/ Questions – (Analyze the data/ theorizing)
Answer the questions on the back of the lab handout (5). Explain that water displacement
(1) was used to get the volume of the irregular shaped pennies. Discuss if different scales were used
for measurement, how that may affect precision, analytical vs. triple beam balance (1). Explain
specifics of your experiment related to the theory (3).
[10] Conclusion – (Was the hypothesis supported or refuted?)
EX: Yes/ No the hypothesis was/ was not supported (1). Compare both pre- and post-1982
densities calculated (2) and discuss in relation to accuracy (percent error) (2), precision (2) and
materials used to mint the coins (1). Give potential reasons for the % error (1). Write a closing
statement with possible implications for future studies or uses (1).
[1] References/ Bibliography – APA format
Hoyumpa, Sept. 10, 2015