As an undergraduate Chemistry, Physics, or Earth Sciences teacher, you can use this set of computer-based tools to teach phase diagrams and phase equilibria.
Phase diagrams can be used to understand the stability of different phases of matter (solid, liquid, and gas) under changing temperature and pressure. This lesson plan will help students learn about phase equilibria through the example of the phase diagram of water. Students will learn about the phases of water on Earth, Mars, and Venus and will discuss the role of the water cycle in making the climate of planet Earth habitable.
Thus, the use of this lesson plan allows you to integrate the teaching of a climate science topic with a core topic in Chemistry, Physics, or Earth Sciences.
This is a Teacher-submitted Lesson Plan.
Contributed by Dr. Upasana Issar, Assistant Professor, Kirori Mal College and Dr. Richa Arora, Assistant Professor, Shivaji College, (University of Delhi), India.
Want to know more about how to contribute? Contact us.
Questions
Use this lesson plan to help your students find answers to:
- What is a phase diagram? Explain the degrees of freedom.
- Define and explain the triple point and critical point in a phase diagram.
- What are supercritical fluids? How are they useful?
- Discuss the water vapor feedback mechanism in the Earth’s atmosphere by using the phase diagram of water.
- Using phase diagrams, explain why the climate of Earth is habitable while the climate of Mars and Venus is not.
- Why did Venus experience a runaway greenhouse effect, resulting in a very high surface temperature (462°C)? Discuss why Earth has not yet experienced this effect.
About Lesson Plan
Grade Level | Undergraduate |
Discipline |
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Topic(s) in Discipline |
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Climate Topic |
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Location | Global |
Language(s) | English |
Access | Online |
Approximate Time Required |
45 – 60 min |
Contents
Micro-lecture (video)
(~12 min) |
A micro-lecture (video) that introduces phase diagrams and explains how they can be interpreted (using the phase diagram of water as an example). |
Reading (10 min) | A reading that describes a typical phase diagram and its components, discusses the phase diagrams of water and carbon dioxide, and provides examples and exercises based on these phase diagrams. |
Micro-lecture (video) (~7 min) and associated reading (15 mins) | A video micro-lecture and an associated reading that describe the phase diagrams of water on Earth, Mars, and Venus. They also discuss the water vapor feedback mechanism in the atmospheres of these planets and the role of this mechanism in the greenhouse effect. Further, these resources explain why the climate of Earth is habitable while that of Mars and Venus is not.
Reading (pg. 127-131, 144) |
Here is a step-by-step guide to using this lesson plan in the classroom/laboratory. We have suggested these steps as a possible plan of action. You may customize the lesson plan according to your preferences and requirements.
1 | Introduce the topic by playing a micro-lecture (video) |
· introduce the topic of phase diagrams · explain what phase diagrams depict by describing their different regions and degrees of freedom · understand how to interpret phase diagrams under varying conditions of temperature and pressure
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2 | Use a reading to discuss the topic further |
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3 | Use a video micro-lecture and an associated reading to explain the reasons for the Earth’s climate being habitable (applying the understanding of phase diagrams) |
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Use the tools and the concepts learned so far to discuss and determine answers to the following questions:
- What is a phase diagram? Explain the degrees of freedom.
- Define the triple point and critical point in a phase diagram.
- What are supercritical fluids? How are they useful?
- Discuss the water vapor feedback mechanism in the Earth’s atmosphere by using the phase diagram of water.
- Using phase diagrams, explain why the climate of Earth is habitable while the climate of Mars and Venus is not.
- Why did Venus experience a runaway greenhouse effect, resulting in a very high surface temperature (462°C)? Discuss why Earth has not yet experienced this effect.
The tools in this lesson plan will enable students to:
- describe a one-component phase diagram
- explain various regions and points (such as the triple point, the critical point) in a phase diagram
- define a supercritical fluid
- compare the climates of Earth, Venus, and Mars with the help of the phase diagram of water
- use the phase diagram to explain the water vapor feedback mechanism in the Earth’s atmosphere and its role in making the planet habitable
If you or your students would like to explore the topic further, these additional resources will be useful.
1 | Classroom/Laboratory Activity | An interactive simulation from PhET, University of Colorado, to explore the phase transformations of water under changing temperature and pressure conditions. |
2 | Video lecture | A video micro-lecture from Coursera that describes the current and past climatic conditions on Mars. |
1 | Micro-lecture (video), “Phase Diagrams” | Presented by Sal Khan for Khan Academy |
2 | Reading, “12.4. Phase Diagrams” | Chapter provided by LibreTextsTM |
3 | a. Micro-lecture (video), “Water Vapor Feedbacks”
b. Reading, Chapter 7, “Feedbacks”, pg. 129-131, pg. 144 from the book “Global Warming- Understanding the Forecast”, 2nd Ed. |
David Archer, the University of Chicago. |
4 | Additional Resources
a. Simulation, “States of Matter: Basics” b. Video lecture, “1.15: Was early Mars warmer and wetter?” |
a. PhET simulation by University of Colorado, Boulder. b. Coursera |
5 | Image | LibreTextsTM |