Making a Scientific Model
How Does Temperature Effect The Volume Of liquids?
Oceanographer: _____________________
Date:____________Period:____
Background
Temperatures on planet earth have been increasing since recording began about 160 years ago. Scientists have not only
detected rising temperatures on land surfaces, but they have detected rising temperatures in our oceans as well. Given that over
70% of the Earth is covered by water, there is concern that warming oceans can affect sea level and impact coastal communities
around the globe, especially equatorial islands.
Objective
In this activity you will hypothesize how increasing temperature will affect the volume of water and then conduct an experiment
to measure and record data.
Materials
Erlenmeyer flask
Two-hole rubber stopper for flask
Thin, glass pipette with graduated markings
Long thermometer
Portable lamp
100 - 150 Watt light bulb
3.5% NaCl solution
Marker
Stopwatch or clock
Figure 1: Lab set up
Hypothesis
Look at figure 1 and assume the flask has been filled completely with water. Write a hypothesis in an, “If…, then…” statement in
the space below about what will happen to the volume of water as heat is applied to the flask of water.
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Procedure
1. Fill the flask with the cold tap water to about 1cm from the top.
2. Place the thermometer and glass tube into the rubber stopper as shown in Figure 1 above.
3. Place the rubber stopper (with tube and thermometer) into the mouth of the flask. The water should rise a short way up the
glass tube. Be sure there is not a gap between the surface of the water and the bottom of the rubber stopper.
4. Record the initial temperature and volume of water in the pipette in the data table.
5. Place the lamp so that it is facing the flask. Do not shine the lamp on the thermometer above the flask.
Record the initial temperature in the table below at time "0".
6. Turn on the heat lamp and record the temperature and water level at one minute intervals.
7. Repeat steps 1-5 with a cold salt water solution (3.5% NaCl).
Data Table 1 – Tap Water
Time (minutes)
0
1
2
3
4
Temperature ( °C)
Initial Pipette Volume
(mL)
Change in pipette volume
(observed-initial)
Percent change in volume
(ΔV%)*
*change in pipette volume/total beginning volume in flask
5
6
7
8
9
10
11
12
13
14
15
Table 2 – 3.5% NaCl Salt Water
Time (minutes)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Temperature ( °C)
Initial Pipette Volume
(mL)
Change in pipette
volume (observedinitial)
Percent change in
volume (ΔV%)*
* change in pipette volume/total beginning volume in flask
Analysis
Using the grid provided, you will construct a graph to help analyze the data from your experiment. Since temperature is the
independent variable that we are investigating, write the temperature values you recorded on the horizontal axis, the x-axis. The
percent change in the volume of water is dependent on the temperature of the water, so volume is the dependent variable and
should be labeled on the vertical axis, the y-axis. Label your axes with the appropriate units included and be sure to include a
descriptive title with your graph.
Draw a line graph showing the effect of temperature on the volume of water. You will graph both your average percent change
in volume and the class average using the data for both the tap water and the 3.5% NaCl salt water solution. Use a different
colored pencil for each of the four lines and be sure to indicate what each color represents in a key. (Use pencil!)
Title _____________________________________________
Results
1. Describe the overall trend in the graph. What is the relationship between temperature and water volume?
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2. Compare the results from Part 1 with tap water with the results from Part 2 with the 3.5% NaCl solution. How did the class
averages compare for the two conditions, tap and salt water? Did the volume change at the same rate in both conditions?
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Conclusion & Application
3. How does this lab model sea level rise with warming temperatures?
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4. Which part of the lab was a better model for thermal expansion and sea level rise? Explain your answer.
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5. How can we change the model to make it a better fit for what we are observing in sea levels? Explain your answer.
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6. Why does water volume increase with increasing temperatures?
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7. How might the change in ocean volume from increasing temperature change coastal areas? Use references for examples to
support your answer.
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8. Are there other causes of sea level rise? If so, what are they, describe them, and how they are influencing sea level.
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