Name:
Learners:
Objectives/Learning
Competency:
Grade 12 Learners
At the end of this lesson, the learners are expected to:
Identify calorimetry as a way to measure heat flow
Sub-tasks;
After this activity, students should be able to:
1. Describe several basic principles of thermodynamics and heat
transfer in action.
2. Compare and contrast the differences between real-world application
and on-paper analysis.
Skills Integration:
Subject Matter:
Topic:
Materials:
Resources:
Procedure
A. Drill
ICT Integration, Communication Skills (Reading, Writing and Output
Creation)
Identifying Materials via Calorimetry
Whiteboard markers, slides with specific heats for common substances
( http://www.engineeringtoolbox.com/specific-heat-capacityd_391.html ) such as water, iron, lead, and copper
https://www.teachengineering.org/activities/view/cub_heat_lesson1_act
ivity1
Activity 1: Flashcards!
Direction: Sets of words that are related to heat and the use of
calorimeter will be shown to class which they will match to a definition
posted in the board. Each student may raise their hand if they wish to
answer.
BIOWORD
HEAT
CALORIMETRY
HEAT FLOW
SPECIFIC HEAT
CELSIUS
DEFINITION
Energy that is transferred
from one body to another as
the result of a difference in
temperature.
the process of measuring the
amount of heat released or
absorbed during a chemical
reaction.
the transfer of heat energy or
enthalpy.
the quantity of heat required to
raise the temperature of one
gram of a substance by one
Celsius degree.
also called centigrade, scale
based on 0° for the freezing
point of water and 100° for
the boiling point of water.
B. Motivation
C. Activity
Ask the students the following questions
1. Do you ever wonder how exactly the number of calories in a
great bag of chips is determined?
2. Or how much energy is contained in a revitalizing soda can?
3. What about reactions involving oxygen and hydrogen?
4. How could a scientist or engineer even try to gauge the energy
emitted given how quickly it reacts?
5. How can reactions be scaled to account for varying reactant
concentrations and sizes?
Most of you are probably thinking, "Well, they look it up of
course!" but the information has to originate someplace. Calorimetry
provides the solution to each of these issues. A calorimeter can be used
to gauge the temperature change that occurs when an object of interest
reacts with a substance that has a known heat capacity. This material is
frequently water. Using specific heat transfer equations, we can then
connect the temperature change to the amount of heat transported.
This activity shows not just the temperatures of solution but also
how we measure these values and the issues we run into when
attempting to do so correctly and affordably in practical settings.
Activity 1: COUNITNG CALORIES (adapted from
TeachEngineering site)
MATERIALS:
For demonstration:
1. 2 beakers
2. KCl (potassium chloride) salt
3. water
4. a thin, lightweight piece of wood or 6-8 Popsicle® sticks
5. thermometer
6. stirring device (such as a Popsicle stick or coffee stirrer)
Each group should have:
7. 2-3 Styrofoam® coffee cups
8. paper cups
9. cloth
10. felt
11. foam
12. thermometer
13. one stir rod
14. water
15. rubber bands
16. tape
17. paper
18. any other materials that may be beneficial for a team's
design
19. Wait, What Just Happened? Worksheet, one per student
20. Your Calorimeter and Your Lab Worksheet, one per
student
21. Evaluation and Improvement Worksheet, one per student
To share with the entire class:
22. scissors
23. aluminum foil
24. potassium chloride
PROCEDURE:
[For teacher] The Styrofoam cups are good insulators (which is part
why we use them for hot coffee). Provide several different materials
and cups for the students, and let them decide what would best insulate
their reaction. One of the better ways to use Styrofoam cups is to nest
them in each other, creating a double layer of insulation. If possible,
avoid air space above the water and below the nested cup. A cap is also
important to prevent heat escaping into the air. Provide cloth and plastic
for use as caps, in addition to regular coffee cup caps. Have students
create some variations on this general theme based on their knowledge
of calorimeters. More background is provided on the associated preworksheet, "Wait, What Just Happened?"
Before the Activity
1. Cool two beakers of 100mL of water to just about freezing.
2. Gather materials.
With the Students
Part 1: Demo
1. Cool two beakers of water to just about freezing.
2. Place enough Popsicle sticks, or the thin piece of wood, on a flat
surface, ensuring that the beaker fits on top of the wood/sticks.
3. Pour some of the ice-cold water from the first beaker onto the
wood/popsicle-sticks.
4. Place the second beaker on top of the wood, making sure there
is water between the wood and glass. In the second beaker, drop
a few teaspoons of salt and stir well.
5. Use a thermometer to measure the temperature as it drops below
0°C (or 32°F, the freezing point of water), even though no ice
has formed inside the beaker.
6. After a couple minutes of the beaker water being at a
temperature below the freezing point of water, lift the beaker off
the table. If the demo was successful, the wood should be frozen
to the beaker.
7. Ask students how much energy it might take to do this per mole
of water. Tell them they need to design a way to measure how
much heat is absorbed in dissolving this salt per gram of salt.
Part 2: Designing a Calorimeter
1. After the demonstration, have the students read the Wait, What
Just Happened? Worksheet .
2. After they have finished reading the background information,
the students should answer the worksheet questions.
3. Next, discuss places where heat can be lost, such as the air, a
table or even a calorimeter.
Show the class the materials available to them for their
calorimeter design. As a class, discuss some of the qualities of the
different materials.
GUIDE QUESTIONS:
 How is a paper cup different than a foam cup?
 How is foil different than felt?
4. Divide the students into groups of 2-3 and have them brainstorm
ideas for what they think would be the most efficient
calorimeter.
5. Have each group design a calorimeter on paper, using the
materials at their disposal.
6. Check to make sure the devices are feasible. If they are not,
direct students to keep thinking and designing. A feasible device
should be able to hold water, and be made of something
somewhat insulating. A cup should probably be used in the
design.
7. Ensure that each group includes access points for thermometer
and stir device. Sign off on feasible designs. See Figure 1 for a
sample calorimeter.
D. Analysis
E. Abstraction
VIRTUAL Experiment:
Have the students perform a virtual experiment on calorimetry,
focusing on answering the problem below:
1. A metal sample with a mass of 500g is heated to 130 degree Celsius
and then dropped into a beaker containing 150 ml of water at 20 degree
Celsius. When thermal equilibrium is reached, the temperature rose to
50 degrees Celsius. Determine the material the metal is made of?
Activity 2: BRAINSTORMING
Direction. Ask students to conduct open discussions in small groups.
Remind students that all ideas should be properly considered and that
no idea or recommendation is "silly." Encourage unconventional
thinking while discouraging idea critique. Ask students to start
brainstorming the best ways to construct a calorimeter before
presenting them with the materials. Should they use a glass jar instead
of a plastic one, a paper cup, or a foam one. Give them time to
brainstorm both crazy and doable ideas so they can start to think like
engineers.
Summary
In this exercise, students build a constant pressure calorimeter to
gauge the temperature of a potassium chloride solution in water,
learning the fundamentals of heat transfer in the process. They begin by
applying analytical approaches to forecast the reaction's heat output.
Then, they use tabular data to compute the specific heat of water and
use that knowledge to forecast the temperature change. The students
will next design and construct a calorimeter before figuring out its
specific heat. Students will test the solution's heat after calculating the
estimated heat lost by the apparatus.
Using a heat transfer equation, the amount of heat released by
the reaction can be determined from the change in water temperature.
They will then compare this to the value they projected using their
calculations, talk about the inaccuracy and its causes, and decide how to
modify their design to reduce these errors before finishing.
Engineering Connection
Large-scale manufacturing facilities and processes that turn
chemicals into useful goods, such as electrical power, food,
pharmaceuticals, materials, fuels, and refined chemicals, are among the
many things that chemical engineers build and run. An engineer needs
to be aware of how much heat will be produced in a specific reaction in
order to apply and manage these processes in a safe and effective
manner. Proteins denature, materials burn or degrade, or a reactor may
ferociously burst, depending on how much heat is produced. Chemical
reactions are inhibited, insufficient energy is produced, or the incorrect
products are favored if too little heat is produced. An engineer must
also be aware of how the chemical process will be impacted by the
process equipment itself. Systems can be created with particular
F. Application
tolerances in mind and reaction conditions can be maximized by
predicting the amount of heat that will be produced in a reaction
(together with pressure).
Activity 5: WAIT, WHAT JUST HAPPENED?
Worksheet: Instruct the students to complete the Wait, What Just What
Happened? Worksheet. Review their answers to gauge their mastery of
the subject..
Assessment
Activity Embedded Assessment
Additional
Activities/Assignme
nt
Your Calorimeter and You Worksheet: Have the students complete the
Your Calorimeter and Your Lab Worksheet. Review their answers to
gauge their mastery of the subject.
Worksheet: Have the students complete the Evaluation and
Improvement Worksheet. Review their answers to gauge their mastery
of the subject.