# UTPA STEM/CBI Courses/Introduction to STEM/Cold and Hot Packs

Course Title: Introduction to STEM
Lecture Topic: Cold and Hot Packs
Instructor: Javier Macossay
Institution: University of Texas - Pan American

## Backwards Design

Course Objectives
* Primary Objectives- By the next class period students will be able to:
** Understand enthalpy and its application in medicine.
* Sub Objectives- The objectives will require that students be able to:
** Learn basic concepts, such as enthalpy, entropy and free energy.
** Understand how these concepts can be used to design cold and hot packs.
** Understand how the cold and hot packs designed can be used in medicine.
** Determine the best chemicals to formulate a cold and a hot pack.
* Difficulties- Students may have difficulty:
** Students will encounter problems understanding enthalpy, entropy and free energy.
* Real-World Contexts- There are many ways that students can use this material in the real-world, such as:
** Cold and hot packs are used in sports medicine to treat injuries. Cold packs prevent inflammation, if applied immediately, in athletes suffering from a twisted ankle or shoulder. However, hot packs are used afterwards to treat swollen injured limbs. Knowledge of Chemistry is needed to understand how to design an effective cold and hot pack.
Model of Knowledge
* Concept Map
** Understanding enthalpy, entropy and free energy.
** Understanding how these concepts can be used to treat injuries.
** Learning the basics of how our body responds to sprains.
** Determination of the enthalpy of several compounds.
** Evaluation and determination of the best compounds to prepare cold and hot packs.
* Content Priorities
** Enduring Understanding
*** Understand the mechanism of action of cold and hot packs.
** Important to Do and Know
*** Learn how to apply concepts such as enthalpy in real life.
** Worth Being Familiar with
*** Identification of the chemicals used in cold and hot packs.
Assessment of Learning
* Formative Assessment
** In Class (groups)
*** Discussion of basic concepts, such as enthalpy, entropy and free energy.
*** Discussion of how cold and hot packs work.
*** Discussion of our bodies’ response to injuries.
*** Discussion of results and conclusions.
** Homework (individual)
*** Internet based search of cold and hot packs.
*** Internet based search of enthalpy, entropy and free energy.
*** Development of a laboratory procedure to determine the enthalpy of several chemicals.
*** Analysis of data and interpretation.
* Summative Assessment
** Discussion in front of the group of the conclusions.

## Legacy Cycle

LOOK AHEAD AND REFLECT BACK
* Goals
** Students should be able to understand the interaction between science and technology and real world applications and impact.
* Objectives
** Students should understand and correlate the concepts learned in a classroom to applications in medicine.
** Students will learn how to determine the enthalpy of a compound.
THE CHALLENGE
You live in the Dallas metropolitan area and the Dallas Cowboys have contacted you as they need your assistance. Jerry Jones wants you to develop cold and hot packs for his team, which uses them extensively after each game and training session. Furthermore, the Cowboys want to add their seal to your product and market your cold and hot packs nationwide. In order to prepare these cold and hot packs, you have to refer back to the basic Physical Chemistry learned while attending UTPA, how would you do it?
GENERATE IDEAS
* Students will research independently the chemicals found in cold and hot packs.
* Students will discuss their ideas through brain storming before performing experiments.
* Students will investigate how to determine the enthalpy of chemicals.
MULTIPLE PERSPECTIVES
Students will discuss among the individuals in each group their ideas.
RESEARCH & REVISE
Students will learn how to interpret laboratory data and draw conclusions based on their experiments’ results.
TEST YOUR METTLE
Students will compare their results against their peers’ observations.
GO PUBLIC
Students will discuss among themselves and in front of the class their results.

## Test Your Mettle Quiz

True or False (50 points)
1. Compounds absorb or release energy when dissolved in a solvent.
2. An endothermic reaction will absorb energy to proceed.
3. An exothermic reaction will absorb energy to proceed.
4. Enthalpy (or change in enthalpy) is the heat transferred in any process.
5. An increase in entropy is viewed as an increase in disorder.
6. An increase in the temperature of a body part will increase blood flow in that area.
7. A chemical commonly used to treat sports injuries on the field is ethyl chloride.
8. Thermodynamics studies the conversion of energy into work and heat.
9. If you cool down an injury (sprain) immediately after it happened, it will help the person to avoid inflammation and cause faster recovery times.
10. The chemicals used in a cold or a hot pack can be mixed a long time before its use and it will still be effective.
Multiple choice (50 points)
11. Enthalpy of dissolution is:
    a) The transfer of heat in any chemical reaction
    b) The transfer of heat in a dissolution process
    c) The transfer of heat in a dissolution process using water only as the solvent
    d) None of the above
    e) More than one of the above
12. Enthalpy is a useful concept in preparing hot and cold packs because:
    a) It allows you to choose the most appropriate chemical for the application desired
    b) You can calculate the enthalpy in the system for treating sore ankles, backs, etc.
    c) More than one of the above
    d) None of the above
13. Ionic compounds are more effective than molecular compounds for cold and hot packs
    a) Yes
    b) No
    c) It depends on the solute (ionic or molecular) – solvent pair used
14. Using rubbing alcohol with water on a person that has high fever is useful because:
    a) The alcohol/water mixture takes heat away from the body, thus increasing the temperature
    b) The alcohol/water mixture takes heat away from the body, thus lowering the temperature
    c) The alcohol/water mixture gives heat to the body, thus increasing the temperature
    d) The alcohol/water mixture gives heat to the body, thus lowering the temperature
    e) None of the above
15. The best chemical to produce a cold pack in water should:
    a) Dissolve quickly
    b) Lower the temperature fast and significantly
    c) Keep a low temperature for a prolonged time
    d) None of the above
    e) More than one of the above