Physical Science 100 – Laboratory
Specific Heat
Materials: Hot plate, beaker, tongs, Styrofoam cups, Laboratory scale, thermometer, Metal
specimens.
Purpose: To identify a mystery metal by calculating its specific heat and comparing results to
known values.
Discussion: You probably have burned your mouth on occasion when eating a hot piece of pizza.
You were probably holding it by the crust, which didn’t feel too hot to the touch, but the cheese and
tomato sauce still burned your mouth. The moisture containing constituents have a high specific
heat capacity, whereas the crust has a low specific heat capacity. Materials or substances with a
high specific heat must gain/lose more energy to raise/lower their temperature by the same amount
as compared to another lower specific heat substance. In this experiment, you are going to compare
the specific heats of some common but different materials.
The specific heat of a material is defined in cal/g˚C. It is the heat necessary to raise the temperature
of 1 gm of a substance 1˚ Celsius. The specific heat of water is 1.00 cal/g˚C. This is also the
definition of 1 calorie, i.e., a calorie is the heat required to raise 1 gram of water 1˚ C.
In this experiment, you will raise the temperature of a specimen to 100˚C by immersing it in boiling
water long enough for it to equilibrate with the temperature of the boiling water. You will then
quickly place the specimen in a cup of room temperature water, which has a specific mass
(measured beforehand) equal to the mass of your specimen. You will then measure the temperature
change in the specimen and the water. The heat gained by the water will equal the heat lost by the
specimen.
We will call the heat lost Qlost and the heat gained Qgained.
Then
Qlost = Qgained
We will define the specific heat of a substance as c and the mass as m and the change in
temperature as ΔT
If
Q = cmΔT
Then
csmsΔTs = cwmw ΔTw
And the specific heat of the specimen is
cs = cwmwΔTw/(msΔTs)
Procedure:
1. Assemble two Styrofoam cups, one inside the other. Do this for each specimen.
These will be used as “calorimeters”.
2. Measure the mass of each specimen.
3. Carefully measure and place in each double cup, a mass of water equivalent to the mass of each
specimen. (NOTE: 1 milliliter of water has a mass of 1 gram.)
4. Measure the temperature of the water in each double Styrofoam cups just before you do step
5 below. Do not remove any of the water with the thermometer (i.e., shake off any clinging
water back into the cup when you remove the thermometer.
5. Take your specimen and its matching cup to the Lab instructor, who will place your specimen
in a beaker of boiling water for a short time until he thinks it has equilibrated with the
temperature of the boiling water.
6. Your instructor will then remove the specimen from the boiling water (quickly shaking off as
much water as possible) and immediately place it in your matching “calorimeter.”
7. Watch the temperature of the specimen and the water in your calorimeter until it
stops changing significantly. Record this final stable temperature.
8. Compare the values you obtain for the specimens to those in the table below and try to identify
the specimen.
9. State any sources of possible error you think might have occurred in you measurements.
TABLE
Specimen Mass T
T
T
ΔT
ΔT
Spec.
water specimen final water specimen Heat
cal/g˚C
SPECIFIC HEATS
SUBSTANCE
Aluminum
Copper
Gold
Lead
Silver
Tungsten
Zinc
Mercury
Water
C (cal/g˚C)
0.215
0.0923
0.0301
0.0305
0.0558
0.0321
0.0925
0.033
1.000
PRE-LAB Questions
1. Define Specific Heat. What are its units?
2. What is specific about specific heat?
3. Why is it possible to use specific heat values to identify a substance?
4. What is the specific heat of water?
5. Define calorie.
POST-LAB Questions
6. The same amount of energy (heat) is added to two samples A & B. Sample A increases its
temperature 10 °C and Sample B increases its temperature 25 ° C. Which sample has the
higher specific heat? Explain how you determined your answer.
7. Substances A & B both experience a temperature increase of 15 °C. Which substance must
have absorbed more heat energy? Explain why.