CORROSION
Corrosion is an electrochemical process in which a metal reacts with a substance in the environment, returning to an ore-like state.
Learning Objectives
By the end of this lesson, students will:
· Understand and be able to explain the concept of corrosion, its causes, and its environmental consequences.
· Understand the relationship between corrosion, galvanic cells and electrochemistry.
· Know and be able to discuss methods used to prevent corrosion.
· Understand and be able to explain the concept of corrosion, its causes, and its environmental consequences.
· Understand the relationship between corrosion, galvanic cells and electrochemistry.
· Know and be able to discuss methods used to prevent corrosion.
Lesson Approaches and Overview (Specific Expectations: F1.2, F2.1, F3.6)
· These short videos are a good introduction, or hook, to corrosion:
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· This lesson provides an invaluable opportunity for students to understand the application of chemistry and chemical research on everyday life. I suggest that when defining corrosion, the emphasis be on its consequences on the environment.
· Start by using examples students know or can relate to. For example, the rooftop of the Peace Tower at the Parliament Buildings in Ottawa, which is made of copper, has a green colour due to the corrosion of copper, and its conversion into copper carbonate.
· Showing the students as many rusted iron objects as possible can complement the discussion of iron corrosion. Ask students to also bring rusted objects to class for class discussion.
· To tie in this lesson with the rest of the unit, it is suggested that metal coatings are directly related to the table of relative strengths of oxidizing and reducing agents.
· The following lesson plan, created by The J. Paul Getty Museum, is a very complete lesson plan. I highly recommend for teachers to use aspects of this lesson plan:
· Start by using examples students know or can relate to. For example, the rooftop of the Peace Tower at the Parliament Buildings in Ottawa, which is made of copper, has a green colour due to the corrosion of copper, and its conversion into copper carbonate.
· Showing the students as many rusted iron objects as possible can complement the discussion of iron corrosion. Ask students to also bring rusted objects to class for class discussion.
· To tie in this lesson with the rest of the unit, it is suggested that metal coatings are directly related to the table of relative strengths of oxidizing and reducing agents.
· The following lesson plan, created by The J. Paul Getty Museum, is a very complete lesson plan. I highly recommend for teachers to use aspects of this lesson plan:
Another lesson plan that would be highly effective is in the following link. This lesson was created by NOAA:
· A PowerPoint presentation that can be used during the lecturing part of the lesson can be found here. This was created by the Vanderbilt Student Volunteers for Science:
· It would be advantageous for students, including those students who are visual and kinesthetic learners, to perform in-class experiments that produce visible results. The following are links to suggested in-class experiments:
· Reinforce the key point that all forms of cathodic protection involve the forcing of iron to become the cathode in any cell that is established. Explain that the only way for iron to be protected from corrosion is to make iron the cathode.
· Here are some links to comprehensive websites that details corrosion, and how it impacts the environment (the problems with corrosion):
· Here are some links to comprehensive websites that details corrosion, and how it impacts the environment (the problems with corrosion):
· The following are some videos that highlight some of the anti-corrosion methods used in modern times. These videos can be used as hooks, consolidation activities, or at any point during the lecture part of the lesson:
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· In order to fulfill specific expectation F1.2, students should be encouraged to discuss and investigate the societal problems of, for example, an underground fuel tank that corrodes and leaks. Stress that it is precisely this reason why the majority of gas stations’ tanks are no longer made of metal for exactly that reason.
· Students can be encouraged to investigate corrosion as the leading cause of structural degeneration of bridges, and how that fact affects the economies of the affected countries. This would also fulfill specific expectation F1.2.
· The following videos are good resources for the environmental issues related to corrosion:
Rust and Bridges:
· Students can be encouraged to investigate corrosion as the leading cause of structural degeneration of bridges, and how that fact affects the economies of the affected countries. This would also fulfill specific expectation F1.2.
· The following videos are good resources for the environmental issues related to corrosion:
Rust and Bridges:
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Rust and Safety (Metallic balconies):
Rust and Ships:
Corrosion and Pipelines (or waterlines):
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Corrosion and Batteries:
· Corrosion engineering is a career in chemistry that students may not know much about. They can be asked to research it, and present it to their peers. The following is a link to a video that explains what corrosion engineering consists of:
· A debrief or consolidation (in addition to any of the suggested activities or videos above), the following website is interactive, and provides an opportunity for students to reinforced the learned concepts, and can be used as an assessment tool by the teacher:
References
- Image on top retrieved from: http://www.milesofsmilesdental.net/wp-content/uploads/2011/09/Corroded-anchor.jpg
- Di Guiseppe, M., Haberer, S., Salciccioli, K., Sanader, M, Vavitsas, A. (2012) Chemistry 12. Toronto: Nelson Education Ltd.
- van Kessel, H., Jenkins, F., Davies, L., Plumb, D., Di Guiseppe, M., Lantz, O., Tompkins, D. (2003). Chemistry 12. Toronto: Thomson Canada Limited