Activity C03: Heat Of Fusion
Activity C03: Heat of Fusion for Ice
(Temperature Sensor)
|Concept |DataStudio |ScienceWorkshop (Mac) |ScienceWorkshop (Win) |
|Phase change |C03 Heat of Fusion.DS |C03 Heat of Fusion |C03_ICET.SWS |
|Equipment Needed |Qty |Equipment Needed |Qty |
|Temperature Sensor (CI-6505A) |1 |Tongs |1 |
|Balance (SE-8723) |1 |Protective gear …show more content…
|PS |
|Base and Support Rod (ME-9355) |1 | | |
|Beaker, 250 mL |2 |Chemicals and Consumables |Qty |
|Clamp, Buret (SE-9446) |1 |Ice, cubes |12 to 15 |
|Graduated cylinder, 100 mL |1 |Styrofoam cup |2 |
|Slit stopper |1 |Towel, paper |2 or 3 |
|Stirring rod |1 |Water, warm (about 60˚ C) |1 L |
What Do You Think?
How does water in the solid phase (ice) become water in the liquid phase, in terms of energy transfer? Does this phase change require energy and does it occur at various temperatures or at a fixed temperature for a pure crystalline solid?
If a change in energy of a system is required to bring about a phase change, how much energy is required to melt a specific amount of the solid?
Take time to answer the ‘What Do You Think?’ question(s) in the Lab Report section.
Background
The change of phase from the solid state to the liquid state is called melting. The temperature at which this occurs for a pure crystalline solid at atmospheric pressure is called its melting point (MP).
Ice made from uncontaminated water can be considered a pure crystalline solid.
The amount of heat energy per gram required to melt a pure crystalline solid at its melting point is called its “Heat of Fusion”. The units for Heat of Fusion are joule/gram.
To calculate the energy that flows from the melting ice, you can use the relationship q = Cp•m•∆T
where q stands for thermal energy (joules), Cp is specific heat (J/g ˚C), m is mass in grams, and ∆T is the change in temperature (˚C). For water, Cp is 4.18 J/g ˚C.
|SAFETY REMINDERS |[pic] |[pic] |[pic] |
|Wear protective gear while handling chemicals. | | | |
|Follow directions for using the equipment. | | | |
|Dispose of all chemicals and solutions properly.
| | | |
For You To Do
In this activity you will observe ice melting in both a qualitative and a quantitative manner.
In the first part of the activity, observe a phase change for ice while measuring the temperature of the system. Use the Temperature Sensor to measure the temperature of a container of ice as small amounts of warm water are added to the ice. Use DataStudio or ScienceWorkshop to record and display the temperature data.
What kind of energy transfer (loss or gain) occurs when ice melts?
In the second part of the activity, use the Temperature Sensor to measure the temperature change while ice melts in warm water. Use DataStudio or ScienceWorkshop to record and display the temperature data. Measure the amount of ice that melts. Use your measurements of the change in temperature and the amount of ice that melted to calculate the Heat of Fusion for ice. Compare your calculation for the Heat of Fusion for ice to the accepted value for the Heat of Fusion.
PART I: Computer Setup
1. Connect the ScienceWorkshop interface to the computer, turn on the interface, and turn on the …show more content…
computer.
2. Connect the DIN plug of the Temperature Sensor into Analog Channel A of the interface.
3. Open the file titled as shown:
|DataStudio |ScienceWorkshop (Mac) |ScienceWorkshop (Win) |
|C02 Heat of Fusion.DS |C02 Heat of Fusion |C02_ICET.SWS |
• The DataStudio file has a Workbook display. Read the instructions in the Workbook.
• The ScienceWorkshop file has a Digits display and a Table display of Temperature.
• Data recording is set for one measurement each ten seconds.
Sensor Calibration
This is an activity where it is good to have accurately calibrated Temperature Sensors, since an actual freezing and melting point is being measured and not just a change in temperature.
Calibrate the Temperature Sensor using two samples of water at known temperatures (e.g., ice-cold water and boiling-hot water).
Hint: Refer to the instruction sheet for the Temperature Sensor, the On-Line Help file for DataStudio, or the User’s Guides for ScienceWorkshop .
PART IIA: Equipment Setup – Add Hot Water to Ice
1. Set up a Styrofoam cup, beaker, and Temperature Sensor as shown.
2. Put approximately 50 or 60 g of crushed ice into the cup.
What do you think the temperature of the ice will be?
PART IIIA: Data Recording – Add Hot Water to Ice
1.
Use the Temperature Sensor to measure the initial temperature of the ice. Measure and record the temperature.
Hint: Use a Digits display and ‘Monitor Data’ in DataStudio or ‘Monitor’ in ScienceWorkshop to see the temperature of the ice.
What do think the temperature of the ice will be?
2. Prepare a container of hot water. Use the Temperature Sensor to measure the initial temperature of the hot water. Measure and record the temperature.
Hot water at 40 ‘C will work just fine. Cooler temperature water may lack the heat necessary to melt the entire ice sample.
3. Add 30 mL of hot water (40˚ C or above) to the ice while stirring the ice/water mixture. Measure and record the temperature.
Is the ice/water mixture warmer, cooler or the same temperature as the initial temperature of the hot water?
If the hot water cooled down, where did its heat energy go?
4. Add another 30 mL of hot water while stirring. Measure and record the temperature.
Carefully observe the mixture and note if there is any remaining ice in the container.
5. Continue to add 30-mL quantities of hot water until all of the ice is melted. Measure and record the temperature of the final
mixture.
Once all of the ice is gone from the container, what happens to the temperature of the mixture?
PART IIB: Equipment Setup – Add Ice to Water
1. Set up the cup, beaker, and the Temperature Sensor as shown.
2. Pour 100.0 mL of water at about 60˚ C into the Styrofoam cup.
3. Get several (7 or 8) large ice cubes.
4. Lower the Temperature Sensor into the warm water (to about 1 cm from the bottom).
PART IIIB: Data Recording – Add Ice to Water
1. Start recording temperature data. (Hint: Click ‘Start’ in DataStudio or ‘REC’ in ScienceWorkshop.)
2. Watch the Digits display. Wait until the temperature reaches a maximum. This maximum will determine the initial temperature, T1, of the water.
Prepare to add ice cubes to the Styrofoam cup. Shake excess water from the ice cubes (or dry them with a paper towel).
3. As soon as this maximum temperature is reached, put ice cubes into the Styrofoam cup.
4. Record the maximum temperature, T1, in your data table.
5. Use a stirring rod to stir the mixture as the temperature approaches 0˚ C.
Important: As the ice melts, add more ice cubes to keep the mixture cold.
6. When the temperature reaches about 0˚ C, use tongs to quickly remove the unmelted ice cubes.
7. Continue stirring until the temperature reaches a minimum (and begins to rise again). This minimum temperature is the final temperature, T2, of the water.
8. Record T2 in your data table.
9. Stop the data recording.
10. Use the 100-mL graduated cylinder to measure the volume of water remaining in the Styrofoam cup to the nearest 0.1 mL. Record this as V2.
Analyzing the Data for PART B – Add Ice to Water
1. Use the Statistics tool in the Table display to check your minimum and maximum temperature values.
2. Subtract T2 - T1 to determine ∆T, the change in water temperature.
3. Calculate the volume of ice that was melted (V2 –V1).
4. Find the mass of ice melted (use 1.00 g/mL as the density of water).
5. Calculate the energy (in joules) released by the 100 g of liquid water as it cooled (q = Cp•m•∆T).
6. Now calculate the heat of fusion, the energy required to melt one gram of ice (in J/g H2O).
7. Use your answer to Step 6 and the molar mass of water to calculate the molar heat of fusion for ice (in kJ/mol H2O).
Equations
[pic]
Record your results in the Lab Report section.
Lab Report - Activity C03: Heat of Fusion for Ice
What do you think?
How does water in the solid phase (ice) become water in the liquid phase, in terms of energy transfer? Does this phase change require energy and does it occur at various temperatures or at a fixed temperature for a pure crystalline solid?
Data Table: Heat of Fusion
|Initial water temperature, T1 (˚C) | |
|Final water temperature, T2 (˚C) | |
|Change in water temperature, ∆T (˚C) | |
|Final water volume, V2, (mL) | |
|Initial water volume, V1, (mL) | |
|Volume of melt, (mL) | |
|Mass of ice melted | g |
|Heat released by cooling water (q = Cp•m•∆T) | J |
|J/g ice melted (Heat of Fusion) | J/g |
|Accepted Heat of Fusion | J/g |
|Percent difference | % |
Questions
1. What is your percent error for the heat of fusion value?
2. What is your percent error for the molar heat of fusion value (see below)? (The accepted value for molar heat of fusion for ice is 6.01 kJ/mol.)
Equations
[pic]
(Temperature Sensor)
|Concept |DataStudio |ScienceWorkshop (Mac) |ScienceWorkshop (Win) |
|Phase change |C03 Heat of Fusion.DS |C03 Heat of Fusion |C03_ICET.SWS |
|Equipment Needed |Qty |Equipment Needed |Qty |
|Temperature Sensor (CI-6505A) |1 |Tongs |1 |
|Balance (SE-8723) |1 |Protective gear …show more content…
|PS |
|Base and Support Rod (ME-9355) |1 | | |
|Beaker, 250 mL |2 |Chemicals and Consumables |Qty |
|Clamp, Buret (SE-9446) |1 |Ice, cubes |12 to 15 |
|Graduated cylinder, 100 mL |1 |Styrofoam cup |2 |
|Slit stopper |1 |Towel, paper |2 or 3 |
|Stirring rod |1 |Water, warm (about 60˚ C) |1 L |
What Do You Think?
How does water in the solid phase (ice) become water in the liquid phase, in terms of energy transfer? Does this phase change require energy and does it occur at various temperatures or at a fixed temperature for a pure crystalline solid?
If a change in energy of a system is required to bring about a phase change, how much energy is required to melt a specific amount of the solid?
Take time to answer the ‘What Do You Think?’ question(s) in the Lab Report section.
Background
The change of phase from the solid state to the liquid state is called melting. The temperature at which this occurs for a pure crystalline solid at atmospheric pressure is called its melting point (MP).
Ice made from uncontaminated water can be considered a pure crystalline solid.
The amount of heat energy per gram required to melt a pure crystalline solid at its melting point is called its “Heat of Fusion”. The units for Heat of Fusion are joule/gram.
To calculate the energy that flows from the melting ice, you can use the relationship q = Cp•m•∆T
where q stands for thermal energy (joules), Cp is specific heat (J/g ˚C), m is mass in grams, and ∆T is the change in temperature (˚C). For water, Cp is 4.18 J/g ˚C.
|SAFETY REMINDERS |[pic] |[pic] |[pic] |
|Wear protective gear while handling chemicals. | | | |
|Follow directions for using the equipment. | | | |
|Dispose of all chemicals and solutions properly.
| | | |
For You To Do
In this activity you will observe ice melting in both a qualitative and a quantitative manner.
In the first part of the activity, observe a phase change for ice while measuring the temperature of the system. Use the Temperature Sensor to measure the temperature of a container of ice as small amounts of warm water are added to the ice. Use DataStudio or ScienceWorkshop to record and display the temperature data.
What kind of energy transfer (loss or gain) occurs when ice melts?
In the second part of the activity, use the Temperature Sensor to measure the temperature change while ice melts in warm water. Use DataStudio or ScienceWorkshop to record and display the temperature data. Measure the amount of ice that melts. Use your measurements of the change in temperature and the amount of ice that melted to calculate the Heat of Fusion for ice. Compare your calculation for the Heat of Fusion for ice to the accepted value for the Heat of Fusion.
PART I: Computer Setup
1. Connect the ScienceWorkshop interface to the computer, turn on the interface, and turn on the …show more content…
computer.
2. Connect the DIN plug of the Temperature Sensor into Analog Channel A of the interface.
3. Open the file titled as shown:
|DataStudio |ScienceWorkshop (Mac) |ScienceWorkshop (Win) |
|C02 Heat of Fusion.DS |C02 Heat of Fusion |C02_ICET.SWS |
• The DataStudio file has a Workbook display. Read the instructions in the Workbook.
• The ScienceWorkshop file has a Digits display and a Table display of Temperature.
• Data recording is set for one measurement each ten seconds.
Sensor Calibration
This is an activity where it is good to have accurately calibrated Temperature Sensors, since an actual freezing and melting point is being measured and not just a change in temperature.
Calibrate the Temperature Sensor using two samples of water at known temperatures (e.g., ice-cold water and boiling-hot water).
Hint: Refer to the instruction sheet for the Temperature Sensor, the On-Line Help file for DataStudio, or the User’s Guides for ScienceWorkshop .
PART IIA: Equipment Setup – Add Hot Water to Ice
1. Set up a Styrofoam cup, beaker, and Temperature Sensor as shown.
2. Put approximately 50 or 60 g of crushed ice into the cup.
What do you think the temperature of the ice will be?
PART IIIA: Data Recording – Add Hot Water to Ice
1.
Use the Temperature Sensor to measure the initial temperature of the ice. Measure and record the temperature.
Hint: Use a Digits display and ‘Monitor Data’ in DataStudio or ‘Monitor’ in ScienceWorkshop to see the temperature of the ice.
What do think the temperature of the ice will be?
2. Prepare a container of hot water. Use the Temperature Sensor to measure the initial temperature of the hot water. Measure and record the temperature.
Hot water at 40 ‘C will work just fine. Cooler temperature water may lack the heat necessary to melt the entire ice sample.
3. Add 30 mL of hot water (40˚ C or above) to the ice while stirring the ice/water mixture. Measure and record the temperature.
Is the ice/water mixture warmer, cooler or the same temperature as the initial temperature of the hot water?
If the hot water cooled down, where did its heat energy go?
4. Add another 30 mL of hot water while stirring. Measure and record the temperature.
Carefully observe the mixture and note if there is any remaining ice in the container.
5. Continue to add 30-mL quantities of hot water until all of the ice is melted. Measure and record the temperature of the final
mixture.
Once all of the ice is gone from the container, what happens to the temperature of the mixture?
PART IIB: Equipment Setup – Add Ice to Water
1. Set up the cup, beaker, and the Temperature Sensor as shown.
2. Pour 100.0 mL of water at about 60˚ C into the Styrofoam cup.
3. Get several (7 or 8) large ice cubes.
4. Lower the Temperature Sensor into the warm water (to about 1 cm from the bottom).
PART IIIB: Data Recording – Add Ice to Water
1. Start recording temperature data. (Hint: Click ‘Start’ in DataStudio or ‘REC’ in ScienceWorkshop.)
2. Watch the Digits display. Wait until the temperature reaches a maximum. This maximum will determine the initial temperature, T1, of the water.
Prepare to add ice cubes to the Styrofoam cup. Shake excess water from the ice cubes (or dry them with a paper towel).
3. As soon as this maximum temperature is reached, put ice cubes into the Styrofoam cup.
4. Record the maximum temperature, T1, in your data table.
5. Use a stirring rod to stir the mixture as the temperature approaches 0˚ C.
Important: As the ice melts, add more ice cubes to keep the mixture cold.
6. When the temperature reaches about 0˚ C, use tongs to quickly remove the unmelted ice cubes.
7. Continue stirring until the temperature reaches a minimum (and begins to rise again). This minimum temperature is the final temperature, T2, of the water.
8. Record T2 in your data table.
9. Stop the data recording.
10. Use the 100-mL graduated cylinder to measure the volume of water remaining in the Styrofoam cup to the nearest 0.1 mL. Record this as V2.
Analyzing the Data for PART B – Add Ice to Water
1. Use the Statistics tool in the Table display to check your minimum and maximum temperature values.
2. Subtract T2 - T1 to determine ∆T, the change in water temperature.
3. Calculate the volume of ice that was melted (V2 –V1).
4. Find the mass of ice melted (use 1.00 g/mL as the density of water).
5. Calculate the energy (in joules) released by the 100 g of liquid water as it cooled (q = Cp•m•∆T).
6. Now calculate the heat of fusion, the energy required to melt one gram of ice (in J/g H2O).
7. Use your answer to Step 6 and the molar mass of water to calculate the molar heat of fusion for ice (in kJ/mol H2O).
Equations
[pic]
Record your results in the Lab Report section.
Lab Report - Activity C03: Heat of Fusion for Ice
What do you think?
How does water in the solid phase (ice) become water in the liquid phase, in terms of energy transfer? Does this phase change require energy and does it occur at various temperatures or at a fixed temperature for a pure crystalline solid?
Data Table: Heat of Fusion
|Initial water temperature, T1 (˚C) | |
|Final water temperature, T2 (˚C) | |
|Change in water temperature, ∆T (˚C) | |
|Final water volume, V2, (mL) | |
|Initial water volume, V1, (mL) | |
|Volume of melt, (mL) | |
|Mass of ice melted | g |
|Heat released by cooling water (q = Cp•m•∆T) | J |
|J/g ice melted (Heat of Fusion) | J/g |
|Accepted Heat of Fusion | J/g |
|Percent difference | % |
Questions
1. What is your percent error for the heat of fusion value?
2. What is your percent error for the molar heat of fusion value (see below)? (The accepted value for molar heat of fusion for ice is 6.01 kJ/mol.)
Equations
[pic]