Science Lab: More Trouble in Candy Cooling Room at Jaw
Breakers, Inc. (Heat Transfer in Liquids)
CONCEPTS: How fast is heat transferred in liquids. Do all liquids transfer heat at
the same rate?
STANDARDS:
GLE 0507.Inq.1 Explore different scientific phenomena by asking questions,
making logical predictions, planning investigations, and recording data.
GLE 0507.Inq.3 Organize data into appropriate tables, graphs, drawings, or
diagrams.
GLE 0507.10.2 Conduct experiments on the transfer of heat energy through
conduction, convection, and radiation.
GLE 0507.Inq.4 Identify and interpret simple patterns of evidence to communicate
the findings of multiple investigations.
GLE 0507.Inq.5 Recognize that people may interpret the same results in different
ways.
GLE 0507.T/E.4 Recognize the connection between scientific advances, new
knowledge, and the availability of new tools and technologies.
EQUIPMENT NEEDED: 2 glass test tubes, 2 chemistry thermometers, an electric
stove burner, a small 2 quart cooking pan,2 test tube holders, 1/8 cup olive oil,
water, Original Hungry Jack syrup (or syrup which is original, NOT “light” syrup.
Light syrups have had the sugar reduced and may not work well for you.)
OPTIONAL EQUIPMENT: smart board or Promethean Board (or iPad which is
internet connected); internet access to createagraph.com.
STUDENT JOBS: Physicists (uses thermometer); timer (uses digital timer); chief
grapher (iPad or laptop); data physicist; group manager (responsible for
insuring that all data is gathered and recorded.
TIME: 30 minutes-one hour
PREVIOUS KNOWLEDGE: Heat can be transferred from hot things to cold
things (or from high temperature matter to low temperature matter)
Have you ever wondered why oil heats up so quickly in a pan, but water takes so
long to boil?
Heat, which is the exchange of energy between a system and its surroundings,
occurs in three major ways: conduction, convection and radiation.
Conduction is heat transfer through touch (physical contact between molecules).
The hotter molecules are, the faster they move around and transfer their energy to
other molecules. Convection is heat transfer through fluid flow, like when hot
water is poured over ice or when cool air is blown over your warm soup. Radiation
occurs when an object releases heat in the form of electromagnetic rays.
An object’s heat capacity describes the amount of heat required to change the
temperature of that object by a certain amount. Specific heat is the amount of heat
required to change the temperature of a substance by one degree (generally °C).
Liquids absorb heat in different ways. The temperature change in a particular liquid
heated by conduction may not be the same trend of temperature change for the
same liquid heated by radiation.
This experiment seeks to look at how different liquids lose their heat and
represent the DATA in a MATHEMATICAL graph format.
OBJECTIVES:
1. Students will record temperatures with 100% accuracy.
2. Students will keep track of time with 100% accuracy.
3. Students will graph data with 100% accuracy.
4. Students will analyze and explain the graph with respect to heat loss.
THE LESSON
What do you know about heat? Where does heat go? (from hot to cold.... ALWAYS)
Can you measure heat transfer? There is something called specific heat (or heat
capacity, or how fast the heat can be changed) and we will be exploring this today.
Here is the problem: I own a candy factory. As you probably know, my specialty is
Jaw Breakers. I cannot tell you some of the secrets....or they wouldn’t be
secrets....but here’s the problem. When we make our fabulous Jaw Breakers,
temperature is very important! Jaw Breakers must cool slowly. We’ve been using
oil, but the Jaw Breakers are not cooling at the right rate. They fall apart. Yikes.
One of my engineers has suggested water, extra light olive oil, or even Original
Hungry Jack syrup might work, but I don’t know which one cools the slowest!
Your teams job is to get me DATA. I need answers people! I’m losing money
(AGAIN) and need answers. Get experimenting!
And I want data. I want you to do experiments, then hand me this information:
1. how fast the water cools 2. how fast the syrup cools 3. how fast the olive oil
cools.
I want DATA people. Back up your recommendation with DATA. I want to see an
accurate graph! You had better be right. The top group(s) who get it exactly right
get promotions. The rest get fired. Welcome to the real world. Now get cracking.
Time is money...and right now I’m losing money, so get going.
I want you to write down a hypothesis at the top of your science notebook and glue
the data chart underneath it.
EXPLAIN THE JOBS (see above)
THE EXPERIMENT
1. Put equal amounts of Original Hungry Jack syrup, Extra Light olive oil, and
water in two different test tubes. Fill each test tube with about 1 inch of each liquid
in the bottom. Try to get them equal. Using test tube clamps, heat the test tubes in
boiling water (submerge the test tubes with syrup, water and olive oil inside which
will heat the contents to boiling) or so they are all three 100 degrees Celsius.
Heating up all three of these to 100 degrees is the INDEPENDENT VARIABLE.
2. Use test tube clamps to lift them out of the boiling water and put them on the test
tube rack (or a clean, empty coffee cup). CAREFULLY record the data EACH
MINUTE for at least 15 minutes. NOTE: PUT THE TEST TUBES IN A TEST
TUBE HOLDER AND DO NOT TOUCH EITHER THE THERMOMETER OR
TEST TUBES FOR THE NEXT 15 ( up to 30 MINUTES). EYES ONLY. NO
TOUCHING. RECORDING THE TEMPERATURE IS THE DEPENDENT
VARIABLE.
3. Record your data on paper. Graph the data on createagraph.com if possible.
See GLE 0507.T/E.4 above.
Data, people! You must have data to back you up.
4. At the end your group will hand me your conclusion: Which loses it’s heat more
slowly: water, light olive oil, or syrup?
The winning team gets a raise. Those who cannot solve my Jaw Breaker problem
may be fired. Good luck.
THE DATA
Use the attached (see below) lab sheet to record your data.
VARIATIONS AND EXTENSIONS OF THE LESSON
There are many variations to this lab. You can change the types of liquids. If
needed, only test two liquids: Original Hungry Jack Syrup and Extra Light Olive
Oil.
The TCAP test asks students questions like:
1. What type of heat transfer occurs in liquids? (convection)
2. Design and carry out experiments and form conclusions.
3. Be able to read and interpret data. SEE GLEs above.
CONCLUSION
Your students will probably get data similar to the graphs below. Make sure the
students write a conclusion at the bottom of their lab page when they are finished.
Which loses its heat slower, water, syrup, or light olive oil? Justify your answer
with DATA.
Does heat transfer happen at the same rate in all liquids? Why or why not? Can
you think of other liquids which might lose heat at different rates?
Did your group design successful tests? Did you record your DATA carefully?
What would you do differently next time? How did you know if someone made a
mistake in recording the temperature?
(See PRODUCTIVE TALK MOVES and STRUCTURING SCIENCE TALK
packet. This gives you excellent ways to teach your students to move forward
and get past yes/no answers and helps them develop strategies for thinking
about the problems.)
The student graphs might be very similar to the graphs below.
HYPOTHESIS:
DATA CHART
Time
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
CONCLUSION:
Temp of Syrup
Temp of water
Temp of light
olive oil
DISCUSSION QUESTIONS:
1. Where does heat go? (from hot to cold.... ALWAYS. It went from the hot syrup
or milk into the glass tube, then into the air. (First CONDUCTION then
CONVECTION)
2. Can you measure heat transfer? (Yes. Actually. We just measured the loss of
heat from the liquid, but it is possible to record the air heating up, for example)
3. Why did the olive oil cool down (LOSE ITS HEAT) faster than the Syrup and the
water? (There is something called specific heat (or heat capacity, or how fast
the heat can be changed) and this allows some materials to hold on to heat
longer, while other materials lose or transfer their heat away faster. Olive oil
has less “heat holding ability than water and syrup.)
4. Can you think of other liquids and materials and how they hold heat? What two
liquids could you test next, and what would you hypothesize the results to be?
(suggestions: cooking oil, water, kayro syrup, salt water, liquid soap are all safe
possibilities)
5. Do you lose heat in the same way as the liquids we just tested? (Yes, we do. You
can hold your hand just over a friends head and feel the heat. Your POOR
TEACHER can feel you transfer heat into the classroom after recess on a warm
day. You can really heat up the classroom in exactly the same way. Since this
test tube of liquid was small you didn’t probably feel the room heat up.)
6. Does heat transfer happen at the same rate in all liquids? (no)
7. Why or why not? (different liquids have unique specific heat. Specific heat is the
amount of heat required to change the temperature of a substance by one degree
(generally °C).
8. Can you think of other liquids which might lose heat at different rates?
9. Did your group design successful tests? Did you record your DATA carefully?
What would you do differently next time?
10. How did you know if someone made a mistake in recording the temperature?
(There would have been a jagged graph. Heat lost was a smooth curved line on
the graph. It doesn’t jump up and down like an EKG of someones heart beat.)
(See PRODUCTIVE TALK MOVES and STRUCTURING SCIENCE TALK
packet. This gives you excellent ways to teach your students to move forward
and get past yes/no answers and helps them develop strategies for thinking
about the problems.
For similar lab ideas see http://sciencefair.math.iit.edu/projects/cooling/
© 2014 Ronald Boston