Specific Heat Lab
On a sunny day, the water in a swimming pool may warm up a degree or two while the concrete around
the pool may become too hot to walk on in your bare feet. This may seem strange because both the
concrete and the water are being heated by the same source-the sun. This evidence suggests it takes
more heat to raise the temperature of some substances more than others.
The amount of heat that is required to raise the temperature of 1 gram of substance by 1 degree Celsius
is called the specific heat of that substance. Water for instance has a specific heat of 4.184 J/g°C. To
measure specific heat in the lab, a calorimeter is used. A calorimeter is a well insulated container used
to measure energy changes. Energy always moves from an object of higher temperature to an object of
lower temperature. The heat gained by the cooler substance equals the heat lost by the warmer
substance, if we assume no heat loss to the surrounding environment.
Heat gained = heat lost
+ q gained = - q lost
In this experiment, you will determine the specific heat of the metal sample. The metal sample will be
heated to a high temperature & then placed in a calorimeter containing a known quantity of water at a
lower temperature. The heat gained by the water will be equal to the heat lost by the meal. It can be
calculated as follows:
Heat gained by water= mass of water x change in temperature of water x specific heat of water.
Equation 1
qwater
= masswater x ΔTwater x Cwater
The specific heat of the metal can then be calculated as follows:
Equation 2
Cmetal = _____q metal____________
massmetal x ΔTmetal
Procedure
1. Fill a 250 ml beaker about half full of water. Place the beaker of water on a hot plate. Begin
heating the water to the boiling point.
2. While the water is heating, weigh and record the mass of the metal sample. List on your data
table which metal you are using.
3. Place the metal carefully in the beaker of water and continue to heat. Leave the metal in the
boiling water while you complete the next 2 steps.
4. Obtain a plastic foam cup to be used as a calorimeter and measure its mass. Record in the data
table.
5. Fill the plastic foam cup about half full of water and measure its mass again. Record in the data
table.
6. While the metal sample is still in the boiling water, measure the temperature of the water and
record. It will be assumed that the temperature of the metal is the same as the boiling
water.
7. Measure the temperature of the water in the plastic foam cup and record the data.
8. Remove the metal sample from the boiling water quickly and transfer it to the plastic foam cup.
9. Immediately place a thermometer in the foam cup and stir the water with the thermometer
recording the highest temperature reached.
10. Pour the water off and save the metal sample. Return to the front table.
Data
Type of Sample
Mass of metal sample
Mass of foam cup
Mass of foam cup and water
Mass of water
Temp. of boiling water (aka: Initial temp. of metal) Ti(metal)
Initial temp. of water in foam cup (before metal was added) Ti H20
Final, highest temp. of water in foam cup (after metal was added) Tf H20 & Tf H20
g
g
g
g
°C
°C
°C
Calculations
1. Calculate the change in temperature of the water in the foam cup. Show work. Answer should
have correct significant figures and units.
2. Calculate the heat gained by the water in the calorimeter using equation 1 on the front of the lab
sheet. Show work. Answer should have correct significant figures and units.
3. Calculate the change in temperature of the metal. Show work. Answer should have correct
significant figures and units. “The final highest temperature of water is also the final temperature of
the metal.”
4. Calculate the specific heat of the metal using equation 2 on the front of the lab sheet. Show work.
Answer should have correct significant figures and units.
The heat gained by the water is the exact same quantity of heat lost by the metal. Use the value
of heat you calculated from question 2 in question 4 but make it a negative value and use as qmetal
5. Calculate the percent error using the accepted values see below.
% =|Accepted – Experimental| x 100
Accepted Values
Accepted
aluminum .899 J/g°C
copper
.384 J/g°C
lead
.129 J/g°C
zinc
.385 J/g°C
brass
.380 J/g°C
Analysis
1. Define specific heat.
2. Write the equation used to calculate heat energy gained or lost and label each variable and
express the typical unit for each.
3. How much energy(in joules) is needed to heat an iron nail with a mass of 7.0 g from 25°C until it
becomes red hot at 750°C.(specific heat of Fe = .447 J/g°C)
4. Out of the accepted values listed in the calculations section, which metal will heat up the fastest
and why?