General Physics Lab I
Physics IC
Third 5 Weeks
Student Laboratory Manual
Metropolitan Community College
All Rights Reserved
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General Physics Lab I
Revision History
Version 1: Fall 2007
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General Physics Lab I
Table of Contents
pg
Introduction ............................................................................................... 5
Week 1:
Lab IC-1: Archimedes Principle ............................................................. 7
Week 2:
Lab IC-2: Charles’ Law and Boyle’s Law ............................................ 11
Week 3:
Lab IC-3: Thermal Expansion............................................................... 15
Week 4:
Lab IC-4: Specific Heat .......................................................................... 19
Week 5:
Lab IC-5: Heat of Fusion ....................................................................... 23
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General Physics Lab I
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General Physics Lab I
Introduction
The experimentation involved in the physics laboratory is an important part of the
scientific method. We will conduct a number of experiments that involve the experience
of using different tools of measurement to better understand the physical processes
involved.
This course will provide a setting for the student to be able to:
1. Build a framework for the understanding of the physical laws that govern the
phenomenon of the universe.
2. Develop problem-solving skills
3. Facilitate an understanding of physical processes through everyday life examples.
4. Carefully take required data in a laboratory setting.
5. Work productively in small groups to solve problems.
6. Be encouraged to study the applications of physics in science.
Materials



Lab Manual for General Physics I
Scientific Calculator
Pens
Safety: Eye protection is required at all times when performing any experiments
involving chemicals. These safety goggles will be provided. You should always clean
your station after you are finished.
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General Physics Lab I
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Archimedes Principle
Physics Lab IC-1
Lab IC-1: Archimedes Principle
In this experiment, Archimedes’ principle will be studied to determine the densities of
solid and liquid samples.
Materials





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
Digital balance or triple-beam pan balance with swing platform
Overflow can
Two containers to hold water
Metal cylinder or block
Block of wood
String
Salt water solution
The buoyant force is described by Archimedes’ principle:
When a body is placed in a fluid, it is buoyed up by a force equal to the weight of
the volume of fluid it displaces.
Specific gravity is a density-type designation that uses water as a comparison standard.
Since it is a weight ratio, specific gravity has no units.
Archimedes’ principle can be used to determine the specific gravity (and thus the density)
of a submerged object:
specific gravity = weight of object (wo) = weight of object (wo) ,
weight of water (ww)
buoyant force (Fb)
where wo is the weight of the object and ww is the weight of the water it displaces, and by
Archimedes’ principle, ww = Fb. For a heavy object that sinks, the net force will be the
weight minus the buoyant force and has a measured apparent weight wo’ = wo – Fb.
Thus, the specific gravity can be written:
specific gravity 
wo
mo
,

'
wo  wo mo  mo'
Eq. 1
(for a heavy object that sinks)
To measure the specific gravity and density of an object that floats (or is less dense than
water), using Archimedes’ principle, it is necessary to use another object of sufficient
weight and density to submerge the light object completely. If m1 is the measured mass
of the wood and the sinker with only the sinker submerged, and m2 is the mass of the
wood and sinker when both are submerged, and mo is the weight of the object in air, then:
mo
,
Eq. 2
specific gravity 
m1  m2
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Physics Lab IC-1
Archimedes Principle
(for a light object that floats)
The specific gravity of a liquid can also be found using Archimedes’ principle, using the
definition:
(m  mo' ) of the liquid
,
Eq. 3
specific gravity  o
(mo  mo' ) of the water
(for a liquid)
Procedure
Part A: Direct Proof of Archimedes’ Principle
1. Weigh the metal sample and record its mass mo and the type of metal on the data sheet.
Also, determine the mass of the empty beaker, mb, and record. Fill the overflow can with
water to the point of overflowing, and place it beneath the scale. Attach a string to the
sample and suspend it from the balance as illustrated.
2. Catch the overflow from the can in the beaker when the sample is immersed. Take a
mass reading mo’ of the object while submerged in water. Make certain that no bubbles
adhere to the object. Then, weight the beaker and water so as to determine the mass of
the displaced water mw.
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Physics Lab IC-1
Archimedes Principle
3. According to Archimedes’ principle, the buoyant force Fb = mog – mo’g should equal
the weight of the displaced water ww =mwg. Compute the buoyant force and compare it
with the weight of the displaced water.
4. Determine the specific gravity and density of the metal sample using Eq. 1.
Type of metal
(in kg)
Mass of metal (mo) in air
Mass of beaker (mb)
Mass of metal (mo’) in submerged in water
Mass of beaker and displaced water (mw + mb)
Mass of displaced water (mw)
(in N)
Weight of displaced water (mwg)
Buoyant force (mo – mo’)g
Difference between Weight of displaced water
and Buoyant force
Specific gravity
(in kg/m3)
Density
Part B: Density of a Light Solid
5. First measure the mass of the wooden block alone (in air). Next, measure the block
and sinker with only the sinker submerged. Finally measure the mass of block and sinker
with both submerged. Use Eq. 2 to solve for the specific gravity (It should be less than
1).
(in kg)
Mass of block in air (mo)
Mass of block and sinker, only sinker submerged (m1)
Mass of block and sinker, both submerged (m2)
Specific gravity
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Physics Lab IC-1
Archimedes Principle
Part C: Density of a Liquid
6. Determine the mass of the object submerged in the saltwater solution. Use Eq. 3 to
solve for the specific gravity (It should be a little more than 1).
(in kg)
Mass of object in air
Mass of object submerged in liquid
Mass of object submerged in water
Specific gravity
Analysis
1. For the object used in Part A, look up the density of the metal used and compare it
with the experimental value. Comment on the purity of the object.
2. Which is heavier, equal volumes of milk or cream? Justify your answer.
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Charles’ Law and Boyle’s Law
Physics Lab IC-2
Lab IC-2: Charles’ Law and Boyle’s Law
Part I: Charles’ Law
Objective: Determine the relationship between volume and temperature of an air bubble.
Procedure
1. Take one of the glass tubes that is close on one end. Find one with an air bubble in
between the layers of oil.
2. Put the glass tube in water baths at different temperatures and measure the length of
the bubble. Record these values in the data sheet.
3. Graph length vs. temperature (in Kelvin)
4. Find the relationship. What is the equation?
Length of Bubble
Temperature (Celsius/Kelvin)
Questions
1. Why is it ok to say the length change of the bubble is proportional to the volume
change of the bubble?
2. What does the y-intercept on the graph mean?
3. Why do we need to change the temperature to Kelvin?
Part II: Boyle’s Law
The primary objective of this experiment is to determine the relationship between the
pressure and volume of a confined gas. The gas we use will be air, and it will be
confined in a syringe connected to a pressure sensor (see Figure 1). When the volume of
the syringe is changed by moving the piston, a change in the pressure exerted by the
confined gas results. This pressure change will be monitored using a pressure sensor
interfaced to a computer. It is assumed that temperature will be constant throughout the
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Charles’ Law and Boyle’s Law
Physics Lab IC-2
experiment. Pressure and volume data pairs will be collected during this experiment and
then analyzed. From the data and graph, you should be able to determine what kind of
mathematical relationship exists between the pressure and volume of the confined gas.
Historically, this relationship was first established by Robert Boyle in 1662 and has since
been known as Boyle’s law.
Figure 1
Materials
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Windows PC
Serial Box Interface or ULI
Data Logger
Vernier Pressure Sensor
20 mL gas syringe
Heavy-wall plastic tubing (~ 1.5 cm long)
Procedure
1. Prepare the Pressure Sensor and an air sample for data collection.
a. Plug the Pressure Sensor into Port 1 of a Serial Box Interface or ULI that is
connected to a computer.
b. Open the screw valve of the Pressure Sensor by turning it ½ turn
counterclockwise.
c. Attach the 20 mL syringe to the valve of the Pressure Sensor via the plastic
tubing as shown in Figure 1. The side opening allows air to enter and exit
when the valve is open.
d. Move the piston of the syringe until the inside black ring is exactly over the
10.0 mL mark. Firmly close the Pressure Sensor’s screw valve by turning it
clockwise.
2. Prepare the computer for data collection by opening “Experiment 6” from the
Chemistry with Computers experiment files. Load the calibration file “Experiment
6.CLB”. The vertical axis has pressure scaled from 0 to 2.5 atm. The horizontal axis
has volume scaled from 0 to 20 mL.
3. Click on the Start button to being data collection.
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Charles’ Law and Boyle’s Law
Physics Lab IC-2
4. Collect the pressure versus volume data. It is best for one person to take care of the
gas syringe and for another to operate the computer.
a. Move the piston to position the inside black ring exactly over the 5.0 mL line
on the syringe. Hold the piston firmly in this position until the pressure value
stabilizes.
b. When the pressure reading has stabilized, click the Keep button. Type “5.0”
in the Volume box. Click the OK button to keep this data pair. If you want to
redo this point, click on the Cancel button.
5. Repeat Step 4 for volumes of 7.5, 10.0, 12.5, 15.0 17.5, and 20.0 mL.
6. Click on the Stop button when you have finished collecting data. Choose Data A
Table from the Windows menu. Record the pressure and volume data pairs in your
data table. Then close the Data A Table window.
7. Examine the graph of pressure versus volume. Based on this graph, decide what kind
of mathematical relationship you think exists between these two variables, direct or
inverse. To see if you made the right choice:
a. Choose Fit from the Analyze menu.
b. In the Fit dialog window click the General button.
c. In the edit box, type in the power of X that represents the relationship shown
in the graph (type “1” if direct, “-1” if inverse).
d. Click the Try Fit button. A best-fit curve will be displayed on the graph. If
the curve has a good match with the data points, then click the Keep As Fit
button. If the curve does not match up well with the points, edit your power
of X to a different value and try the new fit.
8. Choose Print Graph from the File menu and print the graph of pressure vs. volume,
showing the best-fit curve.
Volume (mL)
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Pressure (atm)
Constant, k (P/V or PV)
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Physics Lab IC-2
Charles’ Law and Boyle’s Law
Questions
1. If the volume is doubled from 5.0 mL to 10.0 mL, what does your data show happens
to the pressure?
2. If the volume is halved from 20.0 mL to 10.0 mL, what does your data show happens
to the pressure?
3. If the volume is tripled from 5.0 mL to 15.0 mL, what does your data show happens
to the pressure?
4. From your answers to the first three questions and the shape of the curve in the plot,
do you think the relationship between pressure and volume of a confined gas is direct
or inverse?
5. Based on your data, what would you expect the pressure to be if the volume of the
syringe was increased to 40.0 mL?
6. Based on your data, what would you expect the pressure to be if the volume of the
syringe was decreased to 2.5 mL?
7. What experimental factors are assumed to be constant in this experiment?
8. To determine if the relationship is inverse or direct, find the proportionality constant,
k, from the data. If this relationship is direct, k = P/V. If it is inverse, k = PV. Based
on your answers to Question 4, choose one of these formulas and calculate k for the P
and V pairs in your data table. Place these values in column 3.
9. How constant were the values for k you obtained?
10. Using P, V, and k, write an equation representing Boyle’s law. Write a verbal
statement that correctly expresses Boyle’s law.
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Physics Lab IC-3
Thermal Expansion
Lab IC-3: Thermal Expansion
When most materials are heated they expand as their temperature increases. However, the
expansion does not depend on the heat input, but rather the temperature change. The
expansion of materials with increased temperature takes place in three dimensions, but
this lab will consider only one-dimensional changes in the length of a rod.
Consider a metal rod of some initial length L0 at some initial temperature T0. The rod is
heated, and its temperature is increased to some new temperature T1. The length of the
rod will increase to a new length L1. The change in length of the rod L is given by L =
L1 – L0.
This change in length L is found to be proportional to the original length of the rod L0
and to the change in temperature T, where T = T1 – T0. In equation form the result is:
Eq. 1
L  L0 T
where  is a constant called the linear coefficient of thermal expansion. Solving Eq. 1
for the constant gives:
L

Eq. 2
L0 T
From the form of Equation 2, it is clear that  is the fractional change in length per unit
change in temperature. The units are (oC)-1. Over the range of temperature used in this
lab, we can assume  is approximately constant.
The apparatus to be used in this lab is shown in Figure 1. It consists of a steam jacket
containing a metal rod about 0.60 m long. The jacket is held by supports at either end.
One of the end supports has a thumbscrew whose purpose is to keep that end of the rod
fixed. The other end support contains an indicator to measure the change in length of the
rod.
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Thermal Expansion
Physics Lab IC-3
Figure 1
There are two types of indicators. One has a micrometer screw with a rotary dial of 100
divisions. Each division is 0.01 mm; therefore one complete turn of the dial is equivalent
to a linear translation of 1 mm. Some micrometer screw indicators have a set of binding
posts on each end support. These can be used to construct an electrical circuit to indicate
when the micrometer screw makes contact with the rod. When using a micrometer
screw-type indicator, it is important to remember to back the screw away from the rod
before the rod is allowed to expand in order to prevent damage to the micrometer screw.
The second type of indicator contains a plunger-activated dial that reads directly in 0.01
mm increments. One complete revolution of the dial corresponds to 1 mm of linear
displacement, with a total of 3.5 mm of displacement possible. When using this type of
indicator, contact is made with the rod, and the rod is allowed to expand against the
plunger, which always remains in contact with the rod.
Procedure
1. Remove the rod from the steam jacket and measure the length of the rod with a meter
stick. Measure to the nearest 0.001 m and record this length as L0 in the Data Table.
2. Replace the rod in the steam jacket and secure the jacket in the support ends. If using
a device that has binding posts, connect the leads from an ohmmeter to each of the
binding posts.
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Physics Lab IC-3
Thermal Expansion
3. Using a one-holed rubber stopper, place a thermometer in the opening provided for
that purpose. The opening is located in the center of the steam jacket. The
thermometer bulb should just barely touch the rod. If the apparatus has been standing
unused for several hours or more, record the temperature after the thermometer is in
contact with the rod. If the steam jacket has been recently heated, run cool water
through the jacket until the entire system is at equilibrium at a temperature near room
temperature. Record the temperature (to the nearest 0.1 oC) in the Data Table as T0.
Adjust the indicator dial until contact is made with the rod. If using the micrometer
type device, contact is indicated by the ohmmeter. Record the indicator dial settings
as D0 in the Data Table.
4. If using the micrometer type indicator, back the screw out several turns at this time.
If using the plunger type indicator, leave it in contact with the rod. It is extremely
critical that there be no disturbance of the rod between this reading and the final
reading after the rod has been heated.
5. Connect the steam supply to the steam jacket with a rubber hose. At the other end of
the jacket, connect a hose from the steam outlet to a beaker to catch the steam
condensation. Pass steam through the jacket for several minutes and monitor the
temperature of the rod. When the temperature has reached its maximum value, record
that value of the temperature (to the nearest 0.1 oC) as T1 in the Data Table.
6. If using the plunger type indicator, simply read the value on the indicator dial. If
using the micrometer type indicator, turn the screw in until it touches the rod as
indicated by the ohmmeter. Record the reading as D1 in the Data Table.
7. Repeat steps 1 through 6 for other metals. Be extremely careful not to burn yourself
on the heated steam jacket. Before beginning the procedure, run cool water through
the apparatus until the new rod and jacket are in equilibrium near room temperature.
8. Enter the known values of  for each of the rods and record them in the Data Table.
Analysis
1. Calculate the increase in length L for each rod from L = D1 – D0 and record each of
them in the Calculations Table.
2. Calculate the increase in temperature T for each rod from T = T1 – T0 and record
each of them in the Calculations Table.
3. Using Equation 2, calculate the linear coefficient of thermal expansion for each rod
and record each in the Calculations Table.
4. Calculate the percentage error for each value by comparing it with the known value
and record in the Calculations Table.
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Thermal Expansion
Physics Lab IC-3
Metal
Known 
(oC)-1
L0 (m)
T0 (oC)
T1 (oC)
D0 (m)
D1 (m)
Data Table
Metal
L (m)
T (oC)
 (oC)-1
% error
Calculations Table
Questions
1. What is the accuracy of your measurements of ?
2. The change in length L could be measured with more accuracy if it were larger.
This could be accomplished by heating the rod with a Bunsen burner to a temperature
considerably higher than 100 oC. Would this be a reasonable alternative? In what
way is steam heat a more workable technique?
3. The original length L0 of the rod was measured only to the nearest 1 mm. Does this
cause a significant error in the final result? Why or why not?
4. Would the measured value of  have been the same or different if lengths were
determined in centimeters instead of meters?
5. A washer is made of brass and has an inside diameter of 2.000 cm and an outside
diameter of 3.000 cm at 20.0 oC. A solid aluminum rod has a diameter of 2.000 cm at
20.0 oC and just fits inside the washer. Both the washer and rod are raised to a
temperature of 150.0 oC. Will the rod still fit inside the washer? If so, how much
smaller is the rod than the opening in the washer? If not, how much larger is the rod
than the opening in the washer?
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Specific Heat
Physics Lab IC-4
Lab IC-4: Specific Heat
In this lab, the principle of calorimetry (heat exchange between objects) will be used to
measure the specific heat of different metals.
Materials:

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Calorimeter and stirrer
Metal Shot (at least three different kinds of metal)
Thermometer
Electric Heating Plate
Containers to hold metal shot
Large Beaker
Tongs
If two objects at different temperatures are placed in thermal contact with each other, the
two objects will eventually reach the same temperature. When they reach the same
temperature, the objects are in thermal equilibrium. Key to this process is the law of
conservation of energy. Since energy in the system (in this case the two objects) can not
be created or destroyed, the net change in energy is zero. Thus, energy (in the form of
heat) must transfer from one object to the other object. We can express this relationship
as:
Heat lost (from first object) = Heat gained (by second object)
Mathematically we describe the heat as:
Q  mcT ,
(Eq 1)
where: Q is the heat energy, m is the mass of the object, c is the specific heat of the
object, and T is the temperature change for the object. The specific heat is defined as
the amount of heat per unit mass required to change the temperature by one degree. We
will measure c using units of cal/g-Co. Thus, we will measure the mass in grams, and the
starting and ending temperature in Co. The heat will be measured in calories.
When trying to measure the heat exchange between two objects, it is important to isolate
the two objects from their surrounding environment. If we do not isolate our system,
then there will be heat loss or gain that will not be included in our calculation. A
calorimeter is a device used to isolate the heat exchanges in our system from the outside
world. The calorimeter used in this laboratory consists of two metal cups held apart by a
plastic ring that produces an insulating air space between the cups. The cups also have an
insulating plastic top containing a hole into which the stirrer is placed and a rubber
stopper with a hole into which a thermometer is placed.
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Physics Lab IC-4
Specific Heat
In this laboratory, we will heat metal shot up to the temperature of steam and then we will
place it into a calorimeter which contains cool water. The metal shot will lose heat and
that heat will transfer to the water, the calorimeter cup, and the stirrer in the calorimeter.
By using a stirrer, we can ensure that the system comes to thermal equilibrium as quickly
as possible, minimizing effects from the surrounding environment. Using the heat
equation, we can write a relationship for this heat exchange:
mmetal cmetal (Tmetal  Teq ) 
mwater c water (Teq  Tinit )  mcal ccal (Teq  Tinit )  mstir cstir (Teq  Tinit )
,
(Eq 2)
where: Tmetal is the initial temperature of the metal shot, Tinit is the initial temperature of
the water-calorimeter-stirrer combination, and Teq is the final equilibrium temperature.
Procedure
1. Place about 250 g of one kind of metal shot into the cup that will be set in the heated
water. Record the amount of shot used in Table 2.
2. Fill the steam generator about half full of water. Keep the water level below the
bottom of the cup containing the metal shot, to make sure the shot stays dry.
3. Carefully place a thermometer into the metal shot.
4. While the shot is heating, determine the mass of the inner calorimeter cup and the
stirrer, and record information in Table 1. Your instructor will provide values for ccal
and cs. Place these values in Table 1.
5. Place about 100g of water into the inner calorimeter cup. Determine the mass of the
water by subtraction and record it in Table 2.
6. Place the inner cup, with the stirrer into the outer sleeve. Place the insulating cover
over the top of the calorimeter.
7. Once the temperature of the metal shot reaches a peak temperature (typically a few
degrees below 100 oC), record both the metal shot temperature (Tmetal) and the watercalorimeter-stirrer temperature (Tinit) in Table 2. Take these temperature values (to
the nearest 0.1 oC) immediately before Step 8.
8. Pull the insulating cover off of the calorimeter, remove the thermometer from the
shot, and quickly transfer the shot to the water. Be careful to assure that none of the
water splashes out of the cup.
9. Place the insulating cover back on the calorimeter and slowly stir the water while
watching the thermometer in the calorimeter. When the maximum temperature is
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Specific Heat
Physics Lab IC-4
reached, record the value (to the nearest 0.1 oC), and record this value as the
equilibrium temperature (Teq), in Table 2.
10. Discard the water but do not lose any of the shot. Place the wet shot on paper towels,
spread out, and allow the shot to dry. Be careful not to mix two kinds of metal shot.
11. For each metal, record the known specific heat and record it in Table 3.
12. Repeat all of the above for two other types of metal shot.
Calculations
In equation 2, all of the variables are known except for the specific heat of the metal shot.
Treating it as the unknown, solve equation 2 for the specific heat of the metal shot and
record the value as the experimental value in Table 2. Calculate the percentage error
between your experimental value and the known value of the specific heat for each type
of metal.
Mass of Cup (in g)
Mass of Stirrer (in g)
Specific Heat (c) for Cup (in cal/g-oC)
Combined Mass
Specific Heat (c) for Stirrer (in cal/g-oC)
Table 1: Masses and specific heats for calorimeter cup and stirrer
Metal
Shot
Mass in grams
Cup +
Stirrer +
Water
Water
Temperatures in oC
Tmetal
Tinit
Teq
Table 2: Data table for calorimetry
To find the water mass (column 4), subtract the column 3 value entered in Table 2 from
the combined mass value entered in Table 1. Use the data in Tables 1 and 2 to calculate
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Specific Heat
Physics Lab IC-4
an experimental value for the specific heat of each metal, using equation 2. Record these
values in Table 3.
Metal
Known
Specific Heat
(cal/g-oC)
Experimental
Specific Heat
(cal/g-oC)
% error
Table 3: Calculation of specific heats
Questions
1. What is the accuracy of your results for the specific heats of the metals? Suggest any
change in the procedure that would improve the results. (Hint: The larger the change
in temperature of the water, the better precision with which it can be measured.)
2. Can you make any quantitative statement about the precision of your results? If you
cannot make such a statement, suggest what measurements would allow you to do so.
3. Suppose the shot were wet and thus included some water at the same temperature as
the shot when it was placed in the calorimeter. How would this affect your results?
Water is often used as a heat storage medium. Does it perform that extremely well, or is
it used just because it is easily obtained and works fairly well? What property of water
determines the answer to this question? How unique is water with respect to this
property?
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Heat of Fusion
Physics Lab IC-5
Lab IC-5: Heat of Fusion
In this lab, the objective is to measure the heat of fusion of water.
Materials:



Calorimeter and stirrer
Thermometer
Ice
We will melt ice in water and measure the temperature difference the water undergoes to
calculate the heat that went into melting the ice and heating the melted ice up to the
equilibrium temperature. We use the same relationships as we did for the Specific Heat
lab:
Heat lost (from first object) = Heat gained (by second object),
Mathematically, we can express the heat loss from the water as:
Q  mcT ,
(Eq 1)
However, for the ice, part of the heat gained goes into melting the ice, at a constant
temperature. This requires another equation:
Q  mL ,
(Eq 2)
where L is the latent heat of fusion for water. The heat lost = heat gain equation
becomes:
mwater c water (Tinit  Teq )  mcal ccal (Tinit  Teq )  mice Lice  mice c water (Teq  T0 ) ,
(Eq 3)
where mwater is the mass of water originally in the calorimeter, mcal is the mass of the
calorimeter, Tinit is the initial temperature of the water-calorimeter combination prior to
adding the ice, Teq is the final equilibrium temperature, and T0 is the initial temperature of
the ice (taken to be 0 oC). The calorimeter loses heat (it cools down) during this
experiment, thus it is on the left hand side of the equation.
Procedure
1. Measure and record the mass of the calorimeter in Table 1.
2. Fill the calorimeter 1/3 full of water. While waiting to for the system to reach thermal
equilibrium, measure and record the total mass of the calorimeter and water. Subtract
the mass of the calorimeter from this value to calculate the mass of water used.
Record this value in Table 1. Once the system comes to thermal equilibrium, record
the temperature (Tinit) in Table 2.
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Heat of Fusion
Physics Lab IC-5
3. Dry some ice cubes with paper towels and add them to the water. Swirl the water to
completely melt the ice cubes one at a time and wait for equilibrium.
4. When the system reaches equilibrium, record the temperature (Teq) in Table 2.
5. Record the total mass of the calorimeter and final amount of water. Subtract the mass
of calorimeter and original water from this value and record as the mass of ice used in
Table 2.
6. Using the collected data, the latent heat of fusion of ice (Lice) can then be calculated.
Calculations
In equation 3, all variables are known or measured except for Lice. We will solve
equation 3 for this value.
Mass of Calorimeter
Cup (in g) (mcal)
Mass of Water
(in g) (mwater)
Specific Heat (ccal) for
Cup (in cal/g-oC)
Specific Heat (cwater)
for Water (in cal/g-oC)
Table 1: Masses and Specific Heats for Calorimeter and Water
Temperatures in oC
Tinit
Teq
Mass of Ice
(in g) (mice)
Table 2: Measured Temperatures and mass of ice used
Use the data captured in Tables 1 and 2 to solve equation 3 for Lwater, the latent heat of
fusion of water. Remember to use T = 0 oC for the initial ice temperature, T0.
Known Latent Heat of Fusion
for Water (cal/g-oC)
Experimental Latent Heat of
Fusion for Water (cal/g-oC)
% error
Table 3: Calculation of Latent Heat of Fusion of Water
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Physics Lab IC-5
Heat of Fusion
Questions
1. Why are we using cwater instead of cice on the right hand side of the equation?
2. Would you expect your results to improve or worsen if you were to increase the
amount of ice used in the experiment (without changing the amount of water used to
melt the ice)?
3. Would you expect your results to improve or worsen if you heated the water prior to
adding the ice?
Based on how you did this experiment, how would you design an experiment to measure
the heat of vaporization of water?
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