Title: Heat and Change
Name__________________________________
Introduction: One way to detect a chemical change is to measure the temperature change of a
reaction. Many chemical changes give off heat or take it in (and feel cold). Not all chemical
changes have energy changes but most do. We measure the change in temperature with a
thermometer.
Materials: CBL & temperature probe, 6 test tubes, test tube rack, salt, sugar, baking soda,
vinegar, alka seltzer tablets, calcium metal, beaker with water, goggles
Procedures:
1. Using the CBLs: The CBLs are TI-73 calculators connected to a base. A temperature probe
is attached to the CBL.. Make sure that the calculator is attached to the CBL by a small
cable.
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Turn the calculator on and clear the screen by pressing the CLEAR button.
Then press the APPS button to bring up the applications.
Select the DataMate program by pressing the number “3.”
The software should start and at the top of the screen you should see a line that
says, “CH1:TEMP(C)” and then a number, probably around 22. This number is the
temperature in Celsius.
Go ahead and check the temperature of various things around the room. See if you can get the
temperature to change.
2. Place a small amount of each substance into a test tube and place the test tubes into a test
tube rack. Your teacher will bring the calcium metal to you. Be very careful when handling
the calcium metal. Make sure to wash your hands thoroughly if you touch it.
3. Fill out the Physical Properties chart below for each substance.
Substance
Salt
Sugar
Baking Soda
Vinegar
Alka Seltzer Tablet
Calcium Metal
Physical Properties
4. Once you have your physical properties written down, predict which substances will take in
heat, release heat or have no change when mixed.
Substance
Salt + water
Sugar + water
Baking Soda + water
Baking Soda + vinegar
Alka Seltzer Tablet + water
Calcium Metal + water
Prediction
take in heat, release heat or no change
5. Salt & Water: Now you are ready to begin the experiment. Place the temperature probe into
the test tube with salt. Start the experiment on the calculator and very quickly add water to
your test tube until it is about half full. Stir the mixture until the calculator finishes taking the
temperature readings. Record your observations in the data table. (To find the low and high
temperatures, use the arrow keys on the calculator to travel up and down the graph line.)
6. Sugar &Water: Place the probe into the test tube with sugar, start the experiment and add
water. Record your observations.
7. Baking Soda & Water: Place the probe into the test tube with baking soda, start the
experiment and add water. Record your observations.
8. Vinegar & Baking Soda: Leave the probe in the test tube with baking soda, start the
experiment, but this time add the vinegar to the baking soda/water mixture. Record your
observations.
9. Alka Seltzer & Water: Place the probe into the test tube with alka seltzer, start the
experiment and add water. Record your observations.
10. Calcium Metal & Water: Place the probe into the test tube with calcium, start the
experiment and add water. Record your observations.
11. Answer the analysis questions and write your conclusion.
Data
Experiment
Salt & Water
Sugar & Water
Baking Soda & Water
Start Temp.
End Temp.
Observations
Vinegar & Baking
Soda
Alka Seltzer & Water
Calcium Metal & Water
Analysis:
1. Which reactions did you correctly predict?
2. What other characteristics of chemical change did you see in the reactions?
3. How is heat and temperature change related to chemical changes?
Conclusion: Write 2 things you learned in complete sentences.