As an undergraduate-level Organic Chemistry teacher, you can use this set of computer-based tools to help you teach infrared (IR) spectroscopy and the use of IR spectra to detect functional groups in organic molecules.
The lesson plan will help students differentiate between IR active molecules and IR inactive molecules. It focuses on the behavior of molecules of gases such as CO2 and water vapor when they interact with IR radiation and helps in explaining the greenhouse effect of the atmosphere.
Thus, the use of this lesson plan allows you to integrate the teaching of a climate science topic with a core topic in Organic Chemistry.
The tools in this lesson plan will enable students to:
Lesson plan idea contributed by Dr. Sharda Pasricha, Associate Professor, Sri Venkateswara College, University of Delhi
Want to know more about how to contribute? Contact us.
| Grade Level | Undergraduate |
| Discipline | Chemistry |
| Topic(s) in Discipline | Environmental Chemistry, Greenhouse Gases, Carbon Chemistry, Molecular Structure of Compounds, Infrared (IR) Spectroscopy, Molecular Vibration, Vibrational Modes, IR Active Molecule, Greenhouse Effect, Diagnostic and Fingerprint Regions of Infrared (IR) Spectra, Stretching and Bending Modes of Vibration |
| Climate Topic | Climate and the Atmosphere, Greenhouse Effect |
| Location | Global |
| Language(s) | English |
| Access | Online |
| Approximate Time Required | 45 – 60 mins |
| Share | |
| Resource Download |
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.
A set of video micro-lectures (~20 min)
Introduce the topic of spectroscopy and explain how different types of spectroscopy are used to elucidate the structures of molecules of organic compounds. Use a series of micro-lectures developed by the Royal Society of Chemistry to
Micro-lecture and reading (~25 min)
Use a micro-lecture and associated reading from Prof. David Archer, the University of Chicago, to discuss the effects of IR absorption on gas molecules; further, explain vibrational modes and why certain atmospheric gases such as carbon dioxide (CO2), water vapor, and methane (CH4) act as greenhouse gases.
Play the video micro-lecture “Greenhouse Gases” available at here to describe the various modes of vibration in polyatomic gas molecules. Use the video to discuss the development of a charge imbalance (electrical dipole) in molecules due to the asymmetrical stretching or bending modes of vibration. Explain that this results in the absorption of heat energy from incident IR radiation in gas molecules such as carbon dioxide (CO2), water vapor, and methane (CH4); therefore, these gases trap the heat energy in the atmosphere and act as greenhouse gases.
Use the associated reading from Prof. David Archer’s book “Global Warming: Understanding the Forecast”, available at here for a detailed description of how chemical bonds respond to incident IR light. Explain that due to electrical dipole moments developed during molecular vibrations, some bonds absorb IR energy of specific frequencies. Use this reading to explain the various vibrational modes in polyatomic gas molecules such as water vapor and carbon dioxide (CO2). Reiterate that the absorption of incident IR radiation by these gas molecules in certain vibrational modes makes them greenhouse gases.
Use this lesson plan to help your students find answers to:
| 1 | Simulation (15-20 min) | This PhET simulation, “The Greenhouse Effect” by University of Colorado, shows the thermal effect of IR radiation in the presence of greenhouse gases. The tool can also be used to visualize the changes in vibrational modes of greenhouse gas molecules on exposure to IR light.
This can be accessed here. |
| 2 | Reading (~10 min) | This reading, “What are the properties of a Greenhouse Gas?” by American Chemical Society, describes the properties and compares the global warming potentials of several greenhouse gases based on their IR spectra.
This can be accessed here |
| 3 | Laboratory activity (~45 min) | The laboratory activity, “Building a spectrometer to explore Infrared Radiation and Greenhouse Gases” by American Chemical Society, helps students to build their own IR spectrometer and to compare the thermal potential of greenhouse gases on absorption of IR radiation.
This can be accessed here. |
| 1 | Video micro-lectures, “Infrared spectroscopy (IR)”, “Chemistry Vignettes: IR Spectroscopy” and “Chemistry Vignettes: Vibrational Modes”: | Royal Society of Chemistry |
| 2 | Video micro-lecture, “Greenhouse Gases”: | Prof. David Archer, the University of Chicago |
| 3 | Reading, “Greenhouse Gases”, Chapter 4, pg. 29-32, from the book “Global Warming: Understanding the Forecast”: | Prof. David Archer, the University of Chicago |
| 4 | Additional Resources |
1. Simulation, “The Greenhouse Effect” pHET Colorado 2. Reading, “Properties of greenhouse gases”: American Chemical Society 3. Laboratory Activity, “Building a Spectrometer to Explore Infrared Radiation and Greenhouse Gases”: American Chemical Society |
| Grade Level | Undergraduate |
| Discipline | Chemistry |
| Topic(s) in Discipline | Infrared (IR) Spectroscopy, Molecular Vibration, Vibrational Modes, IR Active Molecule, IR Absorption and Greenhouse Gases, Greenhouse Effect, Diagnostic and Fingerprint Regions of Infrared (IR) Spectra, Stretching and Bending Modes of Vibration |
| Climate Topic | Climate and the Atmosphere, The Greenhouse Effect |
| Location | Global |
| Language(s) | English |
| Access | Online |
| Approximate Time Required | 45 – 60 mins |
| Share | |
| Resource Download |
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.
A set of video micro-lectures (~20 min)
Introduce the topic of spectroscopy and explain how different types of spectroscopy are used to elucidate the structures of molecules of organic compounds. Use a series of micro-lectures developed by the Royal Society of Chemistry to
Micro-lecture and reading (~25 min)
Use a micro-lecture and associated reading from Prof. David Archer, the University of Chicago, to discuss the effects of IR absorption on gas molecules; further, explain vibrational modes and why certain atmospheric gases such as carbon dioxide (CO2), water vapor, and methane (CH4) act as greenhouse gases.
Play the video micro-lecture “Greenhouse Gases” available at HERE to describe the various modes of vibration in polyatomic gas molecules. Use the video to discuss the development of a charge imbalance (electrical dipole) in molecules due to the asymmetrical stretching or bending modes of vibration. Explain that this results in the absorption of heat energy from incident IR radiation in gas molecules such as carbon dioxide (CO2), water vapor, and methane (CH4); therefore, these gases trap the heat energy in the atmosphere and act as greenhouse gases.
Use the associated reading from Prof. David Archer’s book “Global Warming: Understanding the Forecast”, available at HERE for a detailed description of how chemical bonds respond to incident IR light. Explain that due to electrical dipole moments developed during molecular vibrations, some bonds absorb IR energy of specific frequencies. Use this reading to explain the various vibrational modes in polyatomic gas molecules such as water vapor and carbon dioxide (CO2). Reiterate that the absorption of incident IR radiation by these gas molecules in certain vibrational modes makes them greenhouse gases.
Suggested questions/assignments for learning evaluation
Use the tools and the concepts learned so far to discuss and determine answers to the following questions:
Use this lesson plan to help your students find answers to:
| 1 | Simulation (15-20 min) | This PhET simulation, “The Greenhouse Effect” by University of Colorado, shows the thermal effect of IR radiation in the presence of greenhouse gases. The tool can also be used to visualize the changes in vibrational modes of greenhouse gas molecules on exposure to IR light.
This can be accessed here. |
| 2 | Reading (~10 min) | This reading, “What are the properties of a Greenhouse Gas?” by American Chemical Society, describes the properties and compares the global warming potentials of several greenhouse gases based on their IR spectra.
This can be accessed here |
| 3 | Laboratory activity (~45 min) | The laboratory activity, “Building a spectrometer to explore Infrared Radiation and Greenhouse Gases” by American Chemical Society, helps students to build their own IR spectrometer and to compare the thermal potential of greenhouse gases on absorption of IR radiation.
This can be accessed here. |
| 1 | Video micro-lectures, “Infrared spectroscopy (IR)”, “Chemistry Vignettes: IR Spectroscopy” and “Chemistry Vignettes: Vibrational Modes”: | Royal Society of Chemistry |
| 2 | Video micro-lecture, “Greenhouse Gases”: | Prof. David Archer, the University of Chicago |
| 3 | Reading, “Greenhouse Gases”, Chapter 4, pg. 29-32, from the book “Global Warming: Understanding the Forecast”: | Prof. David Archer, the University of Chicago |
| 4 | Additional Resources | 1. Simulation, “The Greenhouse Effect”: pHET Colorado 2. Reading, “Properties of greenhouse gases”: American Chemical Society3. Laboratory Activity, “Building a Spectrometer to Explore Infrared Radiation and Greenhouse Gases”: American Chemical Society |
