EXPERIMENT
Specific Heat Capacity of
Metals
Peter Jeschofnig, Ph.D.
Version 42-0277-00-01
Review the safety materials and wear goggles when
working with chemicals. Read the entire exercise
before you begin. Take time to organize the materials
you will need and set aside a safe work space in
which to complete the exercise.
Experiment Summary:
Students will learn about specific heat capacity and
how to calculate it. They will set up a calorimeter to
measure the heat changes of two different metals
and calculate the specific heat of each metal.
Students will compare the calculated value with
given values to determine experimental error.
www.HOLscience.com
1
© Hands-On Labs, Inc.
Experiment
Specific Heat Capacity of Metals
Objectives
●●
To understand the concept of heat capacity
●●
To learn how to calculate specific heat capacity
●●
To measure the specific heat capacity of two different metals
Time Allocation: 2 hours
www.HOLscience.com
2
©Hands-On Labs, Inc.
Experiment
Specific Heat Capacity of Metals
Materials
MATERIALS
FROM:
Student Provides
LABEL OR
BOX/BAG:
From LabPaq String & Weight
Bag
Weights Bag
String &
Weight Bag
Weights Bag
QTY
ITEM DESCRIPTION:
1
1
1
1
1
4
3
1
Cooking pot for boiling water
Stovetop or heat source
Drinking glass
Tap water
Fork
Washers (may be separate or may be included in
the Centripetal force apparatus, depending on the
LabPaq)
Cup, Styrofoam, 8 oz
Cylinder, 25 mL
1
1
Digital scale
Thermometer-in-cardboard-tube
1
String - Qty-4.0 Meters
1
Weight, 1/2 oz. (avg 14.2 g)
Note: The packaging and/or materials in this LabPaq may differ slightly from that which is listed
above. For an exact listing of materials, refer to the Contents List form included in the LabPaq.
www.HOLscience.com
3
©Hands-On Labs, Inc.
Experiment
Specific Heat Capacity of Metals
Discussion and Review
When heat energy (Q) is added to a material, the temperature of that material rises. The
temperature is measured in degrees Celsius (°C) or in kelvins (K), while the specific heat of that
material is measured in calories (cal) or joules (J). The International System of Units (SI) unit for
specific heat is joules per kilogram kelvin (J/kg · K).
Heat capacity is the proportionality constant between the heat an object absorbs or loses and the
resulting temperature change of the object.
Specific heat capacity (c) measures the amount of heat needed to increase the temperature of
a mass of a material by one degree. The greater a material’s specific heat, the more energy must
be added to increase its temperature. For example, the specific heat of water is 1.00 cal/g · °C or
4180 J/kg · K. This value means that 1.00 calorie of heat is needed to raise one gram of water by
one degree, or 4180 joules of heat is needed to raise one kilogram of water by one degree.
According to the law of conservation of energy, when two substances at different temperatures
come into contact with one another, heat energy is transferred between them. For example, if
you place a piece of hot metal into a container of cold water, the water and its container will
become warmer, while the metal will become cooler, until an equilibrium temperature is reached.
To measure the specific heat of an unknown substance, a calorimeter is used. In your lab exercise,
you will design and use a calorimeter to determine the metals that compose your washers and
weights. See Table 1 for a list of specific heat values for various materials. To calculate specific
heat, you use the following equation:
Q
= cm ∆T
Where Q represents heat needed to change temperature; c represents specific heat capacity; m
represents mass; and ∆T represents change in temperature.
Table 1. Some specific heats of common materials at room temperature.
Substance
Water
Air
Styrofoam
Copper
Glass
Lead
Steel
Specific Heat
J/kg · K
cal/g · °C
4180
1001
1131
386
840
128
500
1.00
0.2391
0.2701
0.0923
0.20
0.0305
0.107
www.HOLscience.com
4
©Hands-On Labs, Inc.
Experiment
Specific Heat Capacity of Metals
Exercise 1: Measuring using a Calorimeter
Procedure
One hour before starting this exercise, fill a glass with tap water and let it sit so it can reach
room temperature.
To keep the heat exchange with the environment to a minimum, you will use well-insulated
calorimeters for this experiment. You will use three Styrofoam cups; two will be used (one inside
the other) and the third will create a cover to minimize heat loss.
1. Construct a calorimeter using three foam cups. One cup will be placed inside of a second cup
for better insulation; the bottom of the third cup will become the calorimeter lid through
which a thermometer can pass.
2. Cut the top portion of the third foam cup so that the bottom portion measures 6 cm high.
(Scissors are recommended for cutting the cup.) Cut a small hole into the bottom center of
the 6-cm cup. This shortened cup will be turned upside down to function as an insulating lid
for your calorimeter. The hole will allow a thermometer to be inserted into the calorimeter so
you can take periodic readings. See Figure 1.
Figure 1: Doubled cup that will serve as the body of the calorimeter (left)
and third, chopped cup that will serve as the calorimeter lid (right).
3. Use a graduated cylinder to measure 25 mL of the room temperature water you set aside
prior to beginning this exercise. Pour the water into the doubled foam cup and cover it with
the lid you constructed in step 2.
4. Measure the temperature (in degrees Celsius) of the water in the calorimeter by inserting the
thermometer through the hole in the lid as shown in Figure 2. Record the temperature in Data
Table 1 in your lab report.
www.HOLscience.com
5
©Hands-On Labs, Inc.
Experiment
Specific Heat Capacity of Metals
Data Table 1: Object Description
Object Description
First Metal
Second Metal
Mass of water in calorimeter, 25 mL = 25 g
Mass of metal object
Starting temperature of water (room temperature)
Starting temperature of object =
Highest final temperature of water & object
Data Table 2: First Metal
Objects
Mass (g)
Tfinal
Tinitial
DT
C (cal/g °C)
DT
C (cal/g °C)
Water in
calorimeter
First metal
Data Table 3: Second Metal
Objects
Mass (g)
Tfinal
Tinitial
Water in
calorimeter
Second metal
5. Use your scale and determine the mass of the first metal object you test. (Whichever you
test first, you will test the other object in the second trial.) Record the measurements in Data
Table 1.
6. Use thread or string to securely tie all of the metal washers together for use in the first trial
of this experiment. Having these items tied together will make it easy for you to remove them
from the cooking pot simultaneously and minimize heat loss. (Similarly, use thread or string
to securely tie the other object for the second trial.)
7. Add the metal objects (lead weight or steel washers) to a cooking pot and add enough water
to fully cover the metal objects and to allow for water evaporation during boiling. (5–10 cm
of water above the metal objects should be enough). Bring the water to boil. (Do not use a
microwave as metal will be added to boiling water.) Turn the heat down low enough to keep
the water lightly boiling for 15 more minutes. www.HOLscience.com
6
©Hands-On Labs, Inc.
Experiment
Specific Heat Capacity of Metals
8. Determine the temperature of the boiling water and record it in Data Table 1. The temperature
of the water equals the temperature of the metal.
9. Use a fork to safely and quickly transfer the metal objects from the boiling water and into the
calorimeter containing the room temperature water.
10.Quickly cover the calorimeter with the foam lid. Put a thermometer through the hole and
extend its tip into the water of the calorimeter. Avoid touching the metal on the very bottom
of the insulated cup.
11.Observe the temperature rise and record the maximum temperature reached. Try to record
this maximum temperature to a quarter-degree accuracy.
12.Discard the water in the calorimeter and repeat steps 3 through 11 using the second metal
object.
Calculations
1. Calculate the specific heat of each metal.
−Q lost by object =
Q gained by water
Note: Negative Q represents heat lost by metal, and positive Q represents heat gained by
water.
2. Solve for the specific heat of each metal (cm). Set up the equation:
−mmc m ∆Tm = mwc w ∆Tw
mm = mass of the metal
cm = specific heat of the metal
DTm = change of temperature of the metal (Tfinal – Tinitial)
mw = mass of water in calorimeter
cw = specific heat of water, 1.00 cal/g °C
DTw = change of temperature of the water (Tfinal – Tinitial)
3. Because you know which metals you have analyzed and have the theoretical specific heat
values for those metals under Table 1, you should be able to calculate the percent error of
your experimentally derived value.
% error =
experimental value − theoretical value
× 100
theoretical value
www.HOLscience.com
7
©Hands-On Labs, Inc.
Experiment
Specific Heat Capacity of Metals
Specific Heat Capacity of Metals
Peter Jeschofnig, Ph.D.
Version 42-0277-00-01
Lab Report Assistant
This document is not meant to be a substitute for a formal laboratory report. The Lab Report
Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables
that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab
reports by providing this information in an editable file which can be sent to an instructor.
Observations
Data Table 1: Object Description
Object Description
First Metal
Second Metal
Mass of water in calorimeter, 25 mL = 25 g
Mass of metal object
Starting temperature of water (room temperature)
Starting temperature of object =
Highest final temperature of water & object
Data Table 2: First Metal
Objects
Mass (g)
Tinitial
Tfinal
DT
C (cal/g °C)
DT
C (cal/g °C)
Water in
calorimeter
First metal
Data Table 3: Second Metal
Objects
Mass (g)
Tinitial
Tfinal
Water in
calorimeter
Second metal
www.HOLscience.com
8
©Hands-On Labs, Inc.
Experiment
Specific Heat Capacity of Metals
Questions
A. Why is it a good idea to start with room temperature water in the calorimeter?
B. Why did we ignore the calorimeter in our calculation although it is listed in the original
equation?
C. When eating apple pie, you may have noticed that the filling seems to be much hotter than
the crust. Why is this? What can you conclude about the specific heat of the filling versus the
specific heat of the crust?
D. Is the heat exchange between the metal and the water in the calorimeter produced by
radiation, conduction, or convection? Explain your answer. www.HOLscience.com
9
©Hands-On Labs, Inc.