2.3.4 Lab: Thermodynamics
Dry Lab
Physics Honors Sem 2
Name:
Dhruva Yerabati
Date:
8/16/24


Thermodynamics

Materials:
Water source with both hot and cold water, or cold water and a hot plate, or cold water and ring stand/ring stand screen and burner
Calorimeter
2 500 mL beakers
2 temperature data acquisition probes
2 Celsius thermometers
Computer
small block of metal (approximately 500 g)
Balance
Tweezers
Ring clamp

Materials for Exploring Further:


Computer with word-processing, spreadsheet, and scientific database functionality available

In this lab, you will investigate how heat is transferred from one material to another. 


Procedure 

Part 1: Heat Transfer from Liquid to Liquid 

1. Set up the computer to measure the real-time temperature from the two temperature probes. 

2. Measure 150 mL of hot water (as hot as a standard faucet provides, or cold water heated to approximately 65°C using a hot plate or a ring stand/ring screen over a burner) in one beaker and 150 mL of cold water (as cold as a standard faucet provides) in another beaker. Place a temperature probe and a Celsius thermometer in each beaker. Wait 30 seconds, and confirm that the temperature measured by each probe matches the temperature on the Celsius thermometer in the same beaker. Record the temperatures in data table 1. (Note: All temperatures in this lab should be recorded in Celsius.) 

3. While you are waiting for the temperature probes to read a final, stable temperature, calculate the expected final temperature of the mixture of hot and cold water. Use the equation Q = mcΔT and the fact that Qlost + Qgained = 0. (The specific heat capacity (c) of water is 4.18 J/g·°C.) Record your prediction in data table 1.

4. Pour the hot and cold water into the calorimeter. Use one of the temperature probes to slowly stir the mixture of water for about 1 minute. Record the final temperature of the mixture in data table 1.

5. Discard the water in the calorimeter.

6. Measure 100 mL of hot water in one beaker and 200 mL of cold water in the other beaker. Place a temperature probe in each beaker. Wait 30 seconds, then record the temperatures in data table 1.

7. While you are waiting for the temperature probes to stabilize, calculate the expected final temperature of the mixture of hot and cold water. Record your prediction in data table 1.

8. Pour the hot and cold water into the calorimeter. Use one of the temperature probes to slowly stir the mixture of water for about 1 minute. Record the final temperature of the mixture in data table 1.

9. Discard the water in the calorimeter.

10. Measure 300 mL of hot water in one beaker and 100 mL of cold water in another beaker. Place a temperature probe in each beaker. Wait 30 seconds and record the temperatures in data table 1.

11. Calculate the expected final temperature of the mixture of hot and cold water. Record your prediction in data table 1.

12. Pour the hot and cold water into the calorimeter. Use one of the temperature probes to slowly stir the mixture of water for about one minute. Record the final temperature of the mixture in data table 1.

13. Discard the water in the calorimeter. 

Data Table 1




Temperature
of hot water
(°C)
Temperature
of cold water
(°C)
Predicted
temperature of
mixed water
(°C)
Actual
temperature of
mixed water
(°C)
150 mL hot
water, 150 mL
cold water

63.3

12.2
 

36.9
100 mL hot
water, 200 mL
cold water

67.2

11.6
 

30.4
300 mL hot
water, 100 mL
cold water

62.7

11.8
 

49.3



Part 2: Heat Transfer from Solid to Liquid 

1. Place the calorimeter on the balance. Press the tare button to zero the balance, so that the calorimeter mass is not included in the displayed mass measurement. Measure 500 g of cold water into the calorimeter. Place a temperature probe in the cold water and wait 30 seconds. Record the temperature of the cold water in data table 2. 

2. Use the balance to measure the mass of the metal block. Pour 300 mL of hot water into one of the beakers. Place the 500 g metal mass or aluminum bar in the hot water. Wait 2 minutes. Place a temperature probe in the hot water and wait 30 seconds. Record the temperature of the hot water in data table 2. 

3. Predict the final temperature of the cold water when combined with the hot metal. Record your prediction in data table 2. 


Metal
Specific heat (J/g°C)
aluminum
0.899
copper
0.385
iron
0.448
lead
0.129
nickel
0.444
zinc
0.385

4. Use tweezers to remove the metal block from the hot water and quickly place it into the cold water in the calorimeter. Use a temperature probe to slowly stir the water for about 1 minute. Record the final temperature of the water in data table 2. 

Data Table 2




Temperature
of cold water
(°C)
Temperature
of hot
water/metal
mass (°C)
Predicted
temperature of
water/metal
block (°C)
Actual
temperature of
water/metal
block (°C)
Mass of cold water: 500 g
Mass of metal block:
_________

13.2

64.5
 

18.3



Part 3: Heat Transfer from Solid to Gas 

1. Ensure that the calorimeter is clean and dry, and that it has not had either hot or cold water in it within the previous 5 minutes. Place a temperature probe in the calorimeter. Record the temperature of the air inside the calorimeter.

2. Pour 300 mL of hot water into one of the beakers, and place the metal block in the hot water. Wait 2 minutes. Place a temperature probe in the water and wait 30 seconds. Record the temperature of the water in data table 3.

3. Predict the final temperature of the air in the calorimeter after the metal is placed in it. Use the same equation you used in part 1. Assume the mass of the air is 1.00 g. Keep in mind that the specific heat capacity (c) of air is 1.00 J/g·°C. Record your prediction in data table 3.

4. Use tweezers to remove the metal block from the hot water and quickly place it into the calorimeter. Wait for the data probe to stabilize, then record the final temperature of the air and metal block in data table 3. 

Data Table 3




Temperature
of air (°C)
Temperature
of hot
water/metal
block (°C)
Predicted final
temperature of
air (°C)
Actual final
temperature of
air (°C)
mass of air: 
1.00g
mass of metal block: 
__________

23.2

65.4
 

35.8




Analyze

1. What happened to the temperature of the cold water when you mixed it with the warm water?


The temperature of the cold water increased as heat was transferred from the warm water to the cold water until thermal equilibrium was reached.






2. What happened to temperature of the cold water when you placed the warm metal block in it?

The temperature of the cold water increased as thermal energy was transferred from the warm metal block to the cold water until they reached a common temperature.







3. How did the calculated final temperatures compare with the actual final temperatures of the water mixtures?

The calculated final temperatures were close to the actual final temperatures, although there may have been small discrepancies due to heat loss to the surroundings or inaccurate measurements.







4. How did your calculated final temperature compare with the actual temperature of the water-metal mixture? What do you think accounts for the difference?
The calculated final temperature was likely slightly different from the actual temperature due to factors such as heat loss to the environment, inaccuracies in specific heat values, or uncertainties in initial temperature measurements.












5. How did your calculated final temperature compare with the actual temperature of the air-metal mixture? Why or how did you make the prediction that you did?
The calculated temperature might not match the actual temperature closely,  possibly due to the assumptions about air’s specific heat capacity and mass. Predictions were based on known specific heat values and assuming no heat loss to the surroundings, which may not hold in practice.



















Draw Conclusions

1. During the experiment with the hot metal block in cold water, in which direction did the thermal energy flow? By what method did the energy flow?


Thermal energy flowed from the hot metal block to the cold water through conduction until they reached thermal equilibrium.














2. During the experiment with the hot metal block in air, in which direction did the thermal energy flow? By what method did the energy flow?



Thermal energy flowed from the hot metal block to the cooler air via conduction, though in typical setups, some heat might have been transferred through convection and radiation.













3. Name the variables that affected the final temperatures of the mixtures.



Variables included the initial temperatures of the substances, their masses, specific heat capacities, and the potential heat loss to the surroundings.













4. Based on your observations of heat transfer through different states of matter, how would you create an efficient system of heat transfer?



An efficient system would involve maximizing conduction area, minimizing heat loss using insulation, and optimizing the state of matter (solid, liquid, or gas) involved for the highest heat transfer coefficient needed for the specific application.
















Explore Further



1. What is the unknown variable in part 2, in which the warmed metal block and the cooler water are combined? How could you determine its value, using the more advanced features of spreadsheets?






The unknown variable is the specific heat capacity of the metal block. It can be determined by setting up the heat transfer equation (Q_{\text{metal}} = Q_{\text{water}}) in a spreadsheet and using solver tools to fit data to experimental results.










2. What is the unknown variable in part 3, in which the warmed metal block and the cooler air are combined? How could you determine its value? How could you use the more advanced features of database software to determine if the experimental value is accurate?

















3. Design an experiment to test the movement of thermal energy by radiation. List the materials and equipment you would need to perform your experiment. Summarize your design and procedure using the more advanced features of a word-processing program.

























4. Use a creative verbal technique, such as an oral presentation, to effectively and persuasively answer the following questions. 

Based on what you have learned about heat flow, as the melting of polar ice into the oceans increases, what do you predict will be the impact on the temperature of the oceans? 

What do you predict are some new problems that could result from this melting?































Copyright © 2019 Apex Learning Inc. Use of this material is subject to Apex Learning's Terms of Use. Any unauthorized copying, reuse, or redistribution is prohibited. Apex Learning ® and the Apex Learning Logo are registered trademarks of Apex Learning Inc.
2.3.4 Lab: Thermodynamics