As a high school or undergraduate Chemistry, Environmental Sciences, or Earth Sciences teacher, you can use this set of computer-based tools to teach about buffers, how buffers work (buffer action), ocean carbonate buffering, and ocean acidification due to higher levels of atmospheric carbon dioxide (CO2).
This lesson plan introduces the topic of buffers and describes carbonate buffering in the ocean when atmospheric CO2 dissolves in seawater. The buffering capacity of the ocean is, however, limited, and therefore, higher concentrations of dissolved CO2 can lead to ocean acidification. Students will use a computer-based activity/model to explore how higher atmospheric CO2 levels (resulting in an increase in dissolved CO2) can lead to ocean acidification. Thus, the use of this lesson plan allows you to integrate the teaching of a climate science topic with a core topic in Chemistry, Environmental Sciences, or Earth Sciences.
As a high school or undergraduate Chemistry, Environmental Sciences, or Earth Sciences teacher, you can use this set of computer-based tools to teach about buffers, how buffers work (buffer action), ocean carbonate buffering, and ocean acidification due to higher levels of atmospheric carbon dioxide (CO2).
This lesson plan introduces the topic of buffers and describes carbonate buffering in the ocean when atmospheric CO2 dissolves in seawater. The buffering capacity of the ocean is, however, limited, and therefore, higher concentrations of dissolved CO2 can lead to ocean acidification. Students will use a computer-based activity/model to explore how higher atmospheric CO2 levels (resulting in an increase in dissolved CO2) can lead to ocean acidification. Thus, the use of this lesson plan allows you to integrate the teaching of a climate science topic with a core topic in Chemistry, Environmental Sciences, or Earth Sciences.
The tools in this lesson plan will enable students to:
Lesson plan based on an idea submitted by Dr. Pragya Gahlot, Sri Venkateswara College (University of Delhi), India.
Want to know more about how to contribute? Contact us.
Lesson plan based on an idea submitted by Dr. Pragya Gahlot, Sri Venkateswara College (University of Delhi), India.
Want to know more about how to contribute? Contact us.
| Grade Level | High School, Undergraduate |
| Discipline | Chemistry |
| Topic(s) in Discipline | Acids and Bases, pH Scale, Ocean Acidification, Buffers, Buffer Action, pH Level, Buffer Capacity, Buffer Range, Acidification, Le Chatelier’s Principle |
| Climate Topic | Climate and the Hydrosphere, Climate and the Atmosphere, Climate and the Biosphere |
| Location | Global |
| Language(s) | English |
| Access | Online |
| Approximate Time Required | 30 – 40 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.
Reading (10 min)
Introduce the topic of buffers. Use the reading “How Does A Buffer Maintain pH?” by LibreTextsTM to explain buffer action and the maintenance of pH in a buffer solution. Explain the term buffer capacity, buffer range, and the pH equation of a given buffer. Use examples (1 and 2) given in the text to calculate changes in the pH values when a weak acid or base is added to a buffer solution. Discuss other examples of buffers in daily life, e.g., the buffering action of blood.
Video micro-lecture (~7 min)
Use the video micro-lecture “Ocean Buffer Chemistry” by Prof. David Archer, University of Chicago, to describe carbonate buffering in the ocean. Discuss how oceans behave as carbon sinks by absorbing atmospheric CO2, and the maintenance of ocean pH levels owing to the buffering capacity of seawater. Further, use the video to explain the buffering range of oceans and the chemical implications of a higher concentration of dissolved CO2 (due to increased levels of atmospheric CO2). Explain how high levels of atmospheric CO2 could result in an excess of free hydrogen (H+ ) ions, thus potentially changing the pH values of seawater (acidification). Further, use the video micro-lecture to illustrate Le Chatelier’s Principle—explain how increased CO2 concentration in seawater sequesters more carbonate (CO3 2- ) ions to keep the system in equilibrium. In conclusion, explain how ocean biota may be affected in the absence of freely available carbonate (CO3 2- ) ions.
Visualization (10-20 min)
Open the applet “Surface Ocean pH Levels” from The King’s Centre for Visualization in Science (KCVS) available at Click Here Select the “Resources” tab to read the background that provides a detailed explanation of the relationship between atmospheric CO2 and ocean pH values. Click on “Help” to read the instructions to run the applet.
Note: Detailed information about SRES projections can be obtained at Click Here
Finally, discuss the implications of the predicted pH value of oceans for different emission scenarios and the possible impacts on the Earth’s biosphere
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 | Laboratory Activity (High School) | A laboratory activity— “The Buffer Zone” by Stefani Hines, University of New Mexico, published in the Environmental Health Perspectives (EHP) Science Education Program—that allows students to explore the buffering ability of seawater and discuss how this buffer action is affected by increasing levels of atmospheric CO2 and increasing global temperatures.
This can be accessed here. |
| 2 | Video | An animated video, “Demystifying ocean acidification and biodiversity impacts” from the California Academy of Sciences, to learn about ocean acidification and its impacts on the biodiversity of the planet.
This can be accessed here |
| 1 | Reading, “How Does A Buffer Maintain pH?” | Chapter provided by LibreTexts |
| 2 | Video micro-lecture, “Ocean Buffer Chemistry” | Prof. David Archer, University of Chicago |
| 3 | Simulation, “Surface Ocean pH Levels” | Developed by The King’s Centre for Visualization in Science (KCVS) |
| 4 | Additional Resources | “The Buffer Zone” by Stefani Hines, University of New Mexico in the Environmental Health Perspectives (EHP) Science Education Program “Demystifying ocean acidification and biodiversity impacts” by the California Academy of Sciences |
| Grade Level | High School, Undergraduate |
| Discipline | Chemistry, Environmental Sciences |
| Topic(s) in Discipline | Buffers, Buffer Action, pH Level, Buffer Capacity, Buffer Range, Acidification, Le Chatelier’s Principle |
| Climate Topic | Climate and the Hydrosphere, Climate and the Atmosphere, Climate and the Biosphere |
| Location | Global |
| Language(s) | English |
| Access | Online |
| Approximate Time Required | 30 – 40 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.
Reading (10 min)
Introduce the topic of buffers. Use the reading “How Does A Buffer Maintain pH?” by LibreTextsTM to explain buffer action and the maintenance of pH in a buffer solution. Explain the term buffer capacity, buffer range, and the pH equation of a given buffer. Use examples (1 and 2) given in the text to calculate changes in the pH values when a weak acid or base is added to a buffer solution. Discuss other examples of buffers in daily life, e.g., the buffering action of blood.
Video micro-lecture (~7 min)
Use the video micro-lecture “Ocean Buffer Chemistry” by Prof. David Archer, University of Chicago, to describe carbonate buffering in the ocean. Discuss how oceans behave as carbon sinks by absorbing atmospheric CO2, and the maintenance of ocean pH levels owing to the buffering capacity of seawater. Further, use the video to explain the buffering range of oceans and the chemical implications of a higher concentration of dissolved CO2 (due to increased levels of atmospheric CO2). Explain how high levels of atmospheric CO2 could result in an excess of free hydrogen (H+ ) ions, thus potentially changing the pH values of seawater (acidification). Further, use the video micro-lecture to illustrate Le Chatelier’s Principle—explain how increased CO2 concentration in seawater sequesters more carbonate (CO3 2- ) ions to keep the system in equilibrium. In conclusion, explain how ocean biota may be affected in the absence of freely available carbonate (CO3 2- ) ions.
Visualization (10-20 min)
Open the applet “Surface Ocean pH Levels” from The King’s Centre for Visualization in Science (KCVS) available at Click Here Select the “Resources” tab to read the background that provides a detailed explanation of the relationship between atmospheric CO2 and ocean pH values. Click on “Help” to read the instructions to run the applet.
Note: Detailed information about SRES projections can be obtained at Click Here
Finally, discuss the implications of the predicted pH value of oceans for different emission scenarios and the possible impacts on the Earth’s biosphere
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 | Laboratory Activity (High School) | A laboratory activity— “The Buffer Zone” by Stefani Hines, University of New Mexico, published in the Environmental Health Perspectives (EHP) Science Education Program—that allows students to explore the buffering ability of seawater and discuss how this buffer action is affected by increasing levels of atmospheric CO2 and increasing global temperatures. This can be accessed here. |
| 2 | Video | An animated video, “Demystifying ocean acidification and biodiversity impacts” from the California Academy of Sciences, to learn about ocean acidification and its impacts on the biodiversity of the planet. This can be accessed here |
| 1 | Reading, “How Does A Buffer Maintain pH?” | Chapter provided by LibreTexts |
| 2 | Video micro-lecture, “Ocean Buffer Chemistry” | Prof. David Archer, University of Chicago |
| 3 | Simulation, “Surface Ocean pH Levels” | Developed by The King’s Centre for Visualization in Science (KCVS) |
| 4 | Additional Resources | “The Buffer Zone” by Stefani Hines, University of New Mexico in the Environmental Health Perspectives (EHP) Science Education Program “Demystifying ocean acidification and biodiversity impacts” by the California Academy of Sciences |
