# Heating Curve Lab

```Heating Curve Lab
Name:
Safety:
1. Because you will be heating glassware, you must wear your __________ ____________.
2. Hot glass looks like _________________ ____________________.
3. Because we will be working with flames, tie back long ____________________ and
don’t wear loose clothing.
Goal:
 To see what happens to the ______________________ of water as it changes phase
from ice to liquid water to gas (steam).
Directions:
1. Fill a 400 mL beaker with ice. Add just enough tap
water to cover the ice.
2. Place a wire gauze on the ring-stand clamp and the
beaker on the wire gauze.
3. Suspend the thermometer as deep in the ice water as
possible without the bulb touching the bottom or
sides.
4. Light the gas burner and adjust the flame, but do not
put it under the beaker until you have adjusted the
height of the beaker. You’ll want the bottom of the
beaker to be right at the top of the inner blue cone of
the flame.
5. Record the beginning temperature of the ice water.
Slide the burner under the beaker and start the timer.
6. Read and record the temperature after each minute.
You may wish to graph the points as you read them.
7. When the water is above 90&deg;C and has been boiling
for 5 minutes, you may stop recording and shut off the flame.
8. Allow the beaker and water to cool in place.
Data:
Attach your data table and graph.
Label your heating curve graph like we did in your notes. Be sure to include labels for: ice melting,
water warming, and water boiling.
Conclusions:
1. What temperature did your ice melt at? Explain how you know.
2. What temperature did your water boil at? Explain how you know.
3. Were the phase changes you observed today exothermic or endothermic and why?
4. If you were adding thermal energy the whole time, why did you have periods where your
temperature did not change much? (What was the thermal energy doing during those time
periods?)
Heating Curve of Lauric Acid
90
5. Look at this graph of a waxy material
called Lauric Acid. At what temperature
does Lauric acid change from a solid to a
liquid?
____________
Describe why
you chose this temperature from the
graph.
Temperature (degrees Celsius)
80
70
60
50
40
30
20
10
0
0
5
10
15
20
Heating Time (minutes)
25
30
```