Chemistry 1
Dr. Nancy Cole
Density of an Unknown Metal Laboratory
Purpose: To determine the identity of a metal by calculating its density.
Materials: Metal pellets of unknown identity, triple beam balance, graduated cylinder
Procedures / Data Collection:
1. On your lab table you have some metal pellets. Count the pellets and record—you must
have the same number of pellets at your lab station when you are finished. You will not be
allowed to leave the lab until all pellets are present. Observe the pellets and make a guess
as to what the metal is, based on the physical appearance.
2. Discuss with your lab partner how to determine the density of your metal sample. Make
three independent determinations of the density of your metal sample. **Take care to
record all relevant pieces of raw data in a data table.
3. Calculate the average density of your metal using the data from your three
trials/determinations. [Show all of your calculations in your lab report!] Compare this
average density to the densities of common elements listed in the Table of Densities
provided at your lab station.
Questions:
1. Based on your calculations, what is your metal sample? Is your sample the same as what
you guessed based on physical appearance alone?
2. After confirming the identity of your metal (i.e., check with me), calculate the percent
error for your determination (Chapter 2, pg. 45).
3. How would your density determination have changed if you had used a different quantity
of the metal for each of the three trials/determinations? Please explain your answer.
**Precautions**:
Chemistry 1
Dr. Nancy Cole
Table of Densities of Common Elements
Name of Element
Density in g/cm3
Aluminum
2.70
Arsenic
5.73
Calcium
1.55
Copper
8.93
Gold
19.3
Iron
7.86
Lead
11.3
Magnesium
1.74
Mercury
13.5
Nickel
8.90
Platinum
21.5
Silver
10.5
Zinc
7.14