Specific Heat of Metals Lab
The specific heat (Cp) of any substance is defined as the amount of heat needed to raise the temperature
of one gram of a substance by one degree Celsius. For example, 4.184 Joules of heat energy is
required to raise the temperature of 1 gram of water from 24C to 25C. So, the Cp of water is 4.184
J/gC. Since it takes 0.44 Joules of heat energy to raise the temperature of 1 gram of iron by 1C, then
the Cp of iron is 0.44 J/gC. Nonmetals absorb heat relatively slowly and have high specific heats,
while metals are good conductors of heat and have low specific heats.
In this lab you will collect data to determine the specific heats of two metals. One metal will be of
known identity (Cu) and the other will be unknown. For the known metal, you will compare your
experimental value to the accepted value in the text and determine % error in order to determine the
accuracy of your lab technique. For the unknown metal, you will determine its identity by comparing
the experimental Cp to the reference values, choosing the closest match, again using % error.
In order to determine Cp, first, a weighed sample of metal is heated. The hot metal is then dropped
into a known mass of cool water in an insulated container, a calorimeter. The temperature of the water
is recorded before and after the metal is added. Upon mixing, the metal transfers some of its heat
energy to the cooler water until equilibrium is reached. Since the specific heat of the water is known,
the amount of heat absorbed by the water (QH2O) can be calculated using Eqn. 1. Since the heat
absorbed by the water is equal to the heat given off by the metal (see Eqn. 2) the specific heat of the
metal can be calculated using Eqn. 3.
Q water = sp. heatwater x masswater x Twater
(Eqn.1)
Qmetal= -Qwater
(Eqn. 2)
Cpmetal =
Qmetal
massmetal Tmetal
(Eqn. 3)
Sample Calculation:
A 59.00 g sample of a metal is heated to 99.5C in a boiling water bath. The initial temperature of the
metal is assumed to be the same as the hot water bath. The hot metal is then poured into a calorimeter
containing 100.0g of water at 20.0C. After stirring for a few minutes, the maximum temperature of the
water/metal mixture is determined to be 24.0C. (Remember that T=Tf  Ti and Q= heat)
First determine heat absorbed by the water using eqn. 1:
Qwater = 4.184 Joules x 100.0 g x (24.0C-20.0C) = 1673.6 J
gC
Using Eqn 2, change the sign to get Qmetal =  1673.6 J
Use Eqn. 3 to determine specific heat for the metal:
sp. heatmetal =
 1673.6 J
=
59.00g x (24.0C-99.5C)
0.3757 ~
0.38 J/goC
Procedure:
Fill a 600 mL beaker about half full with tap water. Add a few boiling chips. Place the beaker on a wire gauze
on the ringstand and use your Bunsen burner to bring the water to a slow boil. While you are waiting for the
water to boil, weigh the first metal in its container and record the mass and metal type.
Carefully transfer the metal to a large test tube. Use test tube holder to place the test tube in the boiling water
bath. Weigh the empty container from the metal and record. Repeat the process for the second metal and place
that test tube in the boiling water bath as well. Be sure to record the mass of the container plus metal, mass of
empty container, and metal type or unknown #.
Each test tube of metal must be heated in the boiling water bath for at least 10 minutes to ensure that the metal
temperature is in equilibrium with the boiling water temperature. Record the boiling water temperature as the
initial temperature of the metals. (Assume the initial temperature of the metal is the same as the temp. of the hot
water bath.)
While the metals are heating, prepare your calorimeter for the first metal. Measure exactly 100.0mL of water
into the calorimeter. Add a temperature probe and stirrer as demonstrated.
After the first metal is heated for 10 minutes, measure and record the temperature of the water in the
calorimeter. This will be Ti for the water.
Using test tube holder, quickly pour the metal pieces into the calorimeter and cover. Gently stir the water for a
few minutes. Record the equilibrium temperature reached by the water in the calorimeter (once temp stops
changing). This temperature will be the final temp. for both the metal and the water, since both metal and water
in calorimeter are now at equilibrium.
To prepare calorimeter for the next metal, decant water from metal, dry metal on paper towels and return the
metal to the original container, leaving the cap off to facilitate air drying. Measure a fresh 100.0 mL sample of
water into the calorimeter and repeat the above procedure with the second metal that has been heating for at
least 10 minutes.
Prelab Assignment:
1. Put a title and purpose for this lab in your lab notebook.
2. Make a raw data table (in your lab book!!) in which to record the following data for two metals
during lab.

type of metal

mass of metal + container

mass of empty container

volume of water in calorimeter

initial temperature of metal (Ti metal)

initial temperature of water (Ti water)

final temperature of metal and water (Tf metal, Tf water).
During lab you will record your data on these lines in ink.
Lab Report:
In addition to the title, purpose and raw data table already in your lab book, add the following to your lab
book.
1. Convert the procedure given on the previous page to flowchart format with boxes for materials. See
prior labs for examples of this format.
2. For each metal, calculate the following:

mass of water in calorimeter

mass of metal

temperature change of metal (Tmetal)

temperature change of water ( Twater)

heat absorbed by water (QH2O) (Use Eqn 1)

heat of metal (Qmetal) (Use Eqn 2)

specific heat of metal (Cp) (Use Eqn 3)
Show all work in a neat, logical, well-labeled format. (Use equations 1, 2 & 3 from the first
page of this handout, see sample calculation below)

% error:
For the Cu, look up the accepted value for Cp and calculate % error
For the unknown metal, look up Cp values for Al, Ni, Pb and Sn and calculate % error
between your experimental value and reference. Determine metal identity by choosing the
lowest % error.
3. Create one table of results for all calculated quantities for both metals. The table MUST include %
error for each metal and the unknown # and chosen identity of your unknown. The table should
have a descriptive title connecting it to this lab.
Note: No conclusion or discussion is required. The focus of this report is on your calculations,
your tables and your procedure.
Approximate grading for the lab report is as follows:
Lab Title -- 2%
Purpose -- 10%
Procedure – 25%
Raw Data in Table recorded DURING LAB, in ink – 10%
Calculations (clearly labeled, with units, sig figs) -- 30%
Formal Results Table – 15% -- must include the determined identity of the unknown metal and %
errors of each Cp value
Participation in lab with partner – 8%