U6 Heating Curve LAB
Purpose
After reading the lab, create your own purpose below:
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Pre-Lab Discussion
When heat is added to ice, it will melt to liquid water. As water is heated, its temperature rises.
Eventually, the water will boil and change into gaseous steam. The substance has now gone
through two phase changes. The temperatures at which these phase changes occur are important
characteristic properties. The relationship between the heat energy and the behavior of the
substance is also important in understanding the difference between heat and temperature. In this
lab experiment you will be discovering the relationship between heat energy and phase changes.
Materials
250 mL Beaker
Bunsen Burner
Ice
Iron Ring
Liquid Water
Ring Stand
Stirring Rod
Thermometer
Test Tube Clamp
Wire Gauze
Procedure
1. Fill a 250 mL beaker with ice. Add water to cover the ice.
2. Place the beaker on the hot plate. Use a test tube clamp to hold a thermometer so that it is
below the water line. Do not let the thermometer rest on the bottom or side of the beaker.
3. Stir carefully around the beaker with a stirring rod until the temperature stabilizes at or
below 0.0 °C. Begin to record the temperature at 30-second intervals in the Data section.
4. After two minutes of consistent readings, set the hot plate to 10, or the highest setting.
Record the time elapsed at the start of heating in the Data section. NOTE: Once the hot
plate is set, leave it at this setting and make no adjustments. Stir continuously while
heating.
5. Continue to record the temperature in the chart in the Data section at 30-second intervals.
6. Record the time at which all the ice has melted in the Data section.
7. Record the time at which the water has begun to boil in the Data section.
8. Continue to heat the water for at least 3 minutes after the water begins to boil, recording
the temperature at 30-second intervals in the Data section.
9. After three minutes of the water boiling, turn off the burner and record the time elapsed in
the Data section.
10. Plot a heating curve (Temperature vs. Time) using your Data on the back of the handout.
 Write an appropriate title for the graph.  Label the x and the y axes.  Include units
for the x and y axes.  Plot all points.  Connect the points with a line.  Label the point
at which the water began “Melting”  Label the point at which the water began
“Boiling”
U6 Heating Curve LAB
Data
Time Elapsed
(minutes : seconds)
Beaker Temperature
(°C)
Time Elapsed
(minutes : seconds)
0:00
13:00
0:30
13:30
1:00
14:00
1:30
14:30
2:00
15:00
2:30
15:30
3:00
16:00
3:30
16:30
4:00
17:00
4:30
17:30
5:00
18:00
5:30
18:30
6:00
19:00
6:30
19:30
7:00
20:00
7:30
20:30
8:00
21:00
8:30
21:30
9:00
22:00
9:30
22:30
10:00
23:00
10:30
23:30
11:00
24:00
11:30
24:30
12:00
25:00
12:30
25:30
Beaker Temperature
(°C)
Heating Start Time___________________
Ice Melting Time_____________________
Heating End Time____________________
Water Boiling Time___________________
U6 Heating Curve LAB
Questions
1. What was happening to the H2O when the lines on the graph were mostly flat? What
evidence could you observe during the lab to support this?
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2. What was happening to the H2O when the lines on the graph were mostly sloped? ? What
evidence could you observe during the lab to support this?
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3. Was the energy flow into the beaker constant? How did you know?
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4. Did this activity involve a chemical change? Explain how you know.
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Conclusion
Based on your heating curve, determine the melting and boiling points of water. Does this match
the accepted values (0°C for melting and 100°C for boiling)? What sources of error (2+) are
there in the experiment that may keep you from having the perfect melting and boiling points?
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Heating Curve4