Name___________________
Period ___ Date __________
CHEMISTRY
Bimetallic Strip Lab
Problem: How can a bimetallic strip be used to measure temperature?
Brass
In the lab, our bimetallic strips are
made of these two alloys
Change in Temp.
Steel
IF
Hypothesis:
a bimetallic strip is heated,
at the quickest rate.
THEN the _______________ will expand
Procedure:
1. Evenly heat the bimetallic strip in a Bunsen burner flame. Observe the bending
behavior and notice which metal expands quicker. Describe your observations in the
data table below. DO NOT TOUCH THE METAL, IT IS HOT!!!
2. Turn on the faucet and slowly put the hot bimetallic strip under the room temperature
water. Observe the (sound) behavior. Describe in data table below. Observe which
metal contracts more.
3. Repeat.
4. Complete questions below.
Data Table:
Observations of HEATED
Bimetallic Strip
Trial 1
Trial 2
Observations of COOLED
Bimetallic Strip
Questions: Use the information obtained from the lab as well as the
“bimetallic strips” information sheet to answer the questions below.
1. Compare the solid bimetallic strip thermometer to a lab liquid (alcohol) thermometer.
a. How are they similar?
b. How are they different?
2. Based on your observations, which metal (brass or steel) expands more when heated?
3. Based on your observations, which metal (brass or steel) contracts more when cooled?
4. Is there evidence to support the statement: “If metal A expands more than metal B when
heated, then metal A also contracts more than metal B when cooled”? Explain.
5. In the diagram on the front of this page, what is the difference between what happens
when you heat the unbonded compared to bonded metals? Why does this occur?
6. How can a bimetallic strip be used to measure temperature?
7. What is thermal expansion?
8. Why are lines (expansion gaps) placed in the cement of sidewalks?
9. What happened to the railroad track in the picture on your bimetallic strips info sheet?
Why?
10. Describe one application/use of a bimetallic strip.