Using Specific Heat to Analyze Metals
In this lab, you will determine the specific heat of steel and aluminum. Then you will use specific heat to analyze the composition of a metal can.
Problem How can you use specific heat to determine the composition of a metal can?
Materials
10 steel bolts
balance
50-cm length of string
clamp
ring stand
boiling water bath (shared with class)
thermometer
500-mL graduated cylinder
ice water
foam cup with lid
aluminum nails
crushed can
For the probeware version of this lab, see the Probeware Lab Manual, Lab 7.
Skills Calculating, Designing Experiments
Procedure
Part A: Determining Specific Heat
Copy the data table shown below.
Measure and record the mass of 10 steel bolts.
Tie the bolts to the string. Use a clamp and ring stand to suspend the bolts in the boiling water bath. CAUTION Be careful not to splash boiling water. After a few minutes, record the water temperature as the initial temperature of the bolts.
Use a graduated cylinder to pour 200 mL of ice water (without ice) into the foam cup. Record the mass and temperature of the ice water. (Hint: The density of water is 1 g/mL.)
Use the clamp to move the bolts into the cup of ice water. Cover the cup and insert the thermometer through the hole in the cover.
Gently swirl the water in the cup. Record the highest temperature as the final temperature for both the water and the steel bolts.
Calculate and record the specific heat of steel. (Hint: Use the equation to calculate the energy the water absorbs.)
Repeat Steps 3 through 7 with aluminum nails to determine the specific heat of aluminum. Start by making a new data table. Use a mass of aluminum that is close to the mass you used for the steel bolts.
Part B: Design Your Own Experiment
Designing Experiments Design an experiment that uses specific heat to identify the metals a can might be made of.
Construct a data table in which to record your observations. After your teacher approves your plan, perform your experiment.
Analyze and Conclude
Comparing and Contrasting Which metal has a higher specific heat, aluminum or steel?
Drawing Conclusions Was the specific heat of the can closer to the specific heat of steel or of aluminum? What can you conclude about the material in the can?
Evaluating Did your observations prove what the can was made of? If not, what other information would you need to be sure?
Inferring The can you used is often called a tin can. The specific heat of tin is 0.23 J/g·°C. Did your data support the idea that the can was made mostly of tin? Explain your answer.