COLEGIO DE MUNTINLUPA
Determination of the heat capacity of the calorimeter
(calorimeter constant)
(Title of Experiment)
Buenaventura, Jiles Gregg A.
(SURNAME, GIVEN NAME, MI) SIGNATURE
OCTOBER 20, 2023
CHEM-LAB CE1B
(SUBJECT CODE AND SECTION) (DATE OF PERFORMANCE)
1 OCTOBER 27, 2023
(GROUP NO.) (DATE OF SUBMISSION)
Objectives:
To determine the heat capacity of the calorimeter, often referred to as the calorimeter
constant.
Introduction:
The determination of the heat capacity of a calorimeter, often referred to as the calorimeter
constant, is a fundamental step in the field of calorimetry. Calorimetry is a vital technique used in
chemistry and physics to measure heat transfer in various processes, including chemical reactions and
phase changes. Understanding the heat capacity of the calorimeter is crucial because it allows us to
correct for the heat exchange that occurs between the substances being investigated and the
calorimeter itself.
In this experiment, we aim to measure the heat capacity of the calorimeter by carefully
observing the changes in temperature that result from mixing hot and cold water within the calorimeter.
By accurately quantifying the heat capacity of the calorimeter, we can ensure the precision and reliability
of subsequent calorimetry experiments. This information is essential for a wide range of applications,
including the study of chemical reactions, the determination of specific heat capacities of substances,
and the calculation of enthalpy changes, also known as the heat of reaction. Through this experiment,
we will gain insights into the principles of heat transfer and the importance of heat capacity in the field
of thermodynamics.
Materials:
Calorimeter (insulated Styrofoam cup with cardboard lid and thermometer hole)
Clamp (for supporting the thermometer)
Graduated cylinder
400 mL beaker
150 mL of water
Thermometer
Stopwatch or timer
Procedure:
1. Calorimeter Setup:
i. Assemble the calorimeter by placing the insulated cup on a stable surface and covering it with
the cardboard lid. Ensure the thermometer hole is aligned correctly.
ii. Use a clamp to support the thermometer inside the hole, making sure it doesn't touch the
sides or bottom of the calorimeter.
iii. Verify that there is enough space in the calorimeter to swirl its contents without the
thermometer getting in the way.
2. Initial Temperature Equilibrium:
i. Measure out 50 mL of cold water using a graduated cylinder and pour it into the calorimeter
cup.
ii. Monitor and record the temperature of the cold water at 30-second intervals until the
temperature remains constant for 2 to 3 readings. This indicates that the water has reached
thermal equilibrium with its surroundings.
3. Hot Water Preparation:
i. While waiting for the cold water to reach equilibrium, heat 150 mL of water in a 400 mL
beaker to a temperature range of 50-60 degrees Celsius.
ii. Measure out 50 mL of the hot water using a graduated cylinder.
iii. Record the initial temperature of the hot water using the thermometer.
4. Temperature Readings:
i. Once the cold water in the calorimeter has reached equilibrium, return the thermometer to
the calorimeter cup.
ii. Record the temperature at 30-second intervals for 3 readings. This will serve as your initial
temperature for the experiment.
5. Mixing Hot Water:
i. Carefully lift the lid of the calorimeter.
ii. Pour the 50 mL of hot water into the calorimeter cup containing the cold water while stirring
continuously to ensure thorough mixing.
iii. Quickly replace the calorimeter lid.
6. Temperature Monitoring:
i. Record the temperature inside the calorimeter at 30-second intervals for a total of 10
minutes. This extended period allows you to collect sufficient data to determine the final
temperature by extrapolation.
7. Cleanup:
i. Dispose of the water in the calorimeter down the sink.
ii. Thoroughly rinse the calorimeter and make sure it's clean for the next trial.
8. Repeat the Experiment: (if necessary)
i. Repeat the entire experiment (from step 2 to step 7) to obtain additional data. This will help
ensure the accuracy of your results.
Remember to follow laboratory safety guidelines, including the use of appropriate personal
protective equipment (lab coat, gloves, safety goggles), and work in a well-ventilated area. Additionally,
ensure that all glassware is clean and dry before use to avoid contamination.
Results and Discussions:
Time (s) Temperature of Cold Water Temperature of Hot Water Temperature of Mixture (°C)
(°C) (°C)
0 Initial Temperature (T₁) Initial Temperature (T2) 36
28 46
30 27 46 36
60 27 46 36
90 36
120 36
150 36
180 36
210 36
240 36
270 36
300 36
Average Temperature (°C) 27.33 46 36
Table 1. Data that were obtained during the trial one of the experiment are shown above.
Time (s) Temperature of Cold Water Temperature of Hot Water Temperature of Mixture (°C)
(°C) (°C)
0 Initial Temperature (T₁) Initial Temperature (T2) 39
28 60
30 27 60 39
60 27 60 39
90 38.5
120 38
150 38
180 38
210 38
240 38
270 37.8
300 37.5
Average Temperature (°C) 27.33 60 38.22
Table 2. Data that were obtained during the trial two of the experiment are shown above.
Time (s) Temperature of Cold Water Temperature of Hot Water Temperature of Mixture (°C)
(°C) (°C)
0 Initial Temperature (T₁) Initial Temperature (T2) 39
28 60
30 27 60 39
60 27 60 38.8
90 38
120 38
150 38
180 38
210 37.5
240 37.5
270 37
300 37
Average Temperature (°C) 27.33 60 37.98
Table 3. Data that were obtained during the trial three of the experiment are shown above.
Solution:
o Heat gain of cold water = Heat loss of hot water
Q GAIN OF COLD WATER = - Q LOSS OF HOT WATER
o Heat is equal to the product of the mass, heat capacity, and the change in temperature.
Q GAIN OF COLD WATER = - Q LOSS OF HOT WATER
mc∆ t COLD WATER = - mc∆ t HOT WATER
o Derive formula to find final temperature.
mc∆ t COLD WATER = - mc∆ t HOT WATER
mc (tf – to COLD WATER) = - mc (tf – to HOT WATER)
mctf – mcto COLD WATER = - mctf + mcto HOT WATER
mctf + mctf = mcto HOT WATER + mcto COLD WATER
mct o HOT WATER+ mct o COLD WATER
tf =
2 mc
Where c is the heat capacity constant of water (4.18 J/KgK)
Computation:
- Trial 1:
mc∆ t COLD WATER = - mc∆ t HOT WATER
mc (tf – to COLD WATER) = - mc (tf – to HOT WATER)
mctf – mcto COLD WATER = - mctf + mcto HOT WATER
mctf + mctf = mcto HOT WATER + mcto COLD WATER
mct o HOT WATER+ mct o COLD WATER
tf =
2 mc
tf =
(
.05 kg 4.18
J
kgK )
( 319 K ) +. 05 kg 4.18 (
J
kgK
(300.33 K ) )
(
2(. 05 kg) 4.18
J
kgK )
tf = 309.665K or 36.665°C
- Trial 2:
mc∆ t COLD WATER = - mc∆ t HOT WATER
mc (tf – to COLD WATER) = - mc (tf – to HOT WATER)
mctf – mcto COLD WATER = - mctf + mcto HOT WATER
mctf + mctf = mcto HOT WATER + mcto COLD WATER
mct o HOT WATER+ mct o COLD WATER
tf =
2 mc
tf =
(
.05 kg 4.18
J
kgK )
( 3 33 K )+ .05 kg 4.18
J
(
kgK
(300.33 K ) )
(
2(.05 kg) 4.18
J
kgK )
tf = 316.665K or 43.665°C
- Trial 3:
mc∆ t COLD WATER = - mc∆ t HOT WATER
mc (tf – to COLD WATER) = - mc (tf – to HOT WATER)
mctf – mcto COLD WATER = - mctf + mcto HOT WATER
mctf + mctf = mcto HOT WATER + mcto COLD WATER
mct o HOT WATER+ mct o COLD WATER
tf =
2 mc
tf =
(
.05 kg 4.18
J
kgK ) (
( 3 33 K )+ .05 kg 4.18
J
kgK )
(300.33 K )
(
2(.05 kg) 4.18
J
kgK )
tf = 316.665K or 43.665°C
Data interpretation:
After conducting three trials of the experiment to determine the heat capacity of the calorimeter, we
have obtained valuable data and insights into the heat exchange processes within the system. In each trial,
we calculated a theoretical final temperature based on the principles of calorimetry and compared it to the
actual final temperature recorded during the experiments.
Here are the results of the three trials:
Trial 1:
Theoretical Final Temperature: 36.665°C
Actual Final Temperature: 36.00°C
Trial 2:
Theoretical Final Temperature: 43.665°C
Actual Final Temperature: 38.22°C
Trial 3:
Theoretical Final Temperature: 43.665°C
Actual Final Temperature: 37.98°C
Analysis:
In Trial 1, the theoretical final temperature was calculated to be 36.665°C, very close to the actual
recorded final temperature of 36.00°C. This indicates that the heat capacity of the calorimeter was accurately
determined in this trial.
In Trial 2, the theoretical final temperature was calculated to be 43.665°C, while the actual final
temperature recorded during the experiment was 38.22°C. There is a notable discrepancy between the
theoretical and actual values in this trial, suggesting that there may have been some heat loss or external
factors affecting the accuracy of the result.
In Trial 3, the theoretical final temperature was again calculated to be 43.665°C, and the actual final
temperature recorded was 37.98°C. Like Trial 2, there is a discrepancy between the theoretical and actual
values, indicating that some heat exchange or experimental error may have influenced the outcome.
Possible Sources of Error:
Heat losses to the surroundings: The calorimeter may not have been perfectly insulated, resulting in
heat exchange with the environment.
Incomplete mixing: Despite efforts to continuously stir the contents, there may have been regions of
uneven temperature distribution within the calorimeter.
Thermometer inaccuracies: The precision of the thermometer and the placement of the thermometer
within the calorimeter can affect the accuracy of temperature readings.
Conclusion:
In summary, while Trial 1 produced results that closely aligned with the theoretical calculations, Trials
2 and 3 exhibited some discrepancies. These discrepancies suggest the need for careful attention to
experimental conditions and possible sources of error. Further refinement of the experimental setup, such as
improving insulation and mixing techniques, may help reduce these discrepancies and lead to more accurate
determinations of the heat capacity of the calorimeter in future experiments.
