Gold Seal Lesson:
How To Prevent The Redox Blues

Copernicus Education Gateway

Subject:

Science

Grade:

9-12

ICLE Standards:

Science as Inquiry: Construct and test a model of a physical system.

Scientific Knowledge: Formulate plans and contingencies that can be used to accommodate for changes to and stresses on systems.

Conditions for Learning Science: Perform an investigation that requires observations over varying periods of time; work as a contributing member of a collaborative research group.

Applications for Scientific Learning: Write, follow, modify and extend instructions; use appropriate technologies to prepare and present the findings of investigations incorporating tables, diagrams or photographs and text.

Performance Task:

Note to the Teacher: This task will take several weeks. Students need to have an understanding oxidation-reduction (redox) reactions for the task. They should also be familiar with the conservation of matter theory and how to produce solutions of a known concentration.

Karz-R-Us, Inc., a U.S. auto parts manufacturer, ships stamped sheet metal parts to the island country of St. Kitts-Nevis. The car repair shops in St. Kitts-Nevis have been complaining about excessive "rust" on previous shipments of the stamped parts (fenders, hoods, and trunk covers). The St. Kitts-Nevis Ministry of Trade and Industry is looking into possible penalties against Karz-R-Us. They have asked the American company to explain why their parts corrode so badly and what action will be taken to prevent such problems in the future. The Engineering Department of Karz-R-Us has been looking into several ways to combat the corrosion of these parts. The parts are made from a "mild" steel, wrapped with heavy paper, loaded on skids and trucked 161 km to the shipyards at the Port of Let. The parts are transported 5200 km to St. Kitts-Nevis on cargo ships traveling at an average speed of 8.2 international knots per hour (kn.). Unfortunately for Karz-R-Us, the shipping company they contracted to deliver the parts to St. Kitts-Nevis is Bill's Aluminum Storm Door and Shipping Service. This particular service is infamous for leaving all the heavy skids tied down to the deck during transport (which is one of the major reasons why three of Bill's ships have capsized...but that's another story).

The engineers are considering the following options to reduce or eliminate the corrosion of the parts:

1. spray the parts with some type of corrosion inhibiting oil after stamping;
2. "shrink-wrap" the parts in a polymer similar to commercial plastic wrap;
3. rely on a process called "cathodic" protection (one of the engineers remembers having read somewhere that ..."if a small piece of copper is in contact with steel, it will keep the steel from corroding);
4. some other process suggested by the team of engineering technicians.

Each of these options has its own unique problems in terms of cost, effectiveness, reliability (these steel parts tend to shift and rub against each other during shipment), ease of application (if it involves coating a part) and the amount of time it will protect the part.
The engineers have decided to let a team of technicians develop and run the corrosion test. 

The following parameters must be considered during the test:

1. length of exposure in the ocean climate, i.e. time on board ship - you will have to calculate this;
2. mass gain/loss;
3. appearance of parts;
4. effectiveness and comparative costs of the proposed corrosion inhibiting processes;
5. photographic and written documentation of the effectiveness/ineffectiveness of the process.

Knowledge / Skills:

Plan and apply real or hypothetical models and constructions to facilitate investigation and learning and the solution to practical problems.  (s115)

Exhibit good data management skills by collecting, organizing, and graphing data.  (s19)

Understand the nature of change in the environment and how it occurs through the occurrence of an event (e.g., altering the properties of matter or of a system). Describe and measure change using time and space relationships as a frame of reference.  (s24

Understand physical/chemical change (e.g., change of phase between gases, liquids, and solids).  (s57)

Participate, sometimes leading, in group meetings by contributing, taking turns speaking, and working toward a common goal.  (ela20)

Understand and produce a variety of informative formats such as business letters, memos, reports, news articles, brochures, proposals and critiques.  (ela22)

Use writing as a tool for learning in formats such as learning logs, laboratory reports, note-taking, and journals.  (ela40)

Rubric:

4 Points  =  The student makes significant contributions to the team on planning, researching, testing and evaluating the best method to reduce corrosion. The experimental design shows originality, adherence to good laboratory techniques, ease of repeatability and thorough research of the problem. The submitted report is well written and documented. All methods were evaluated and subjected to thorough scrutiny. The proposed solution meets the required parameters of cost effectiveness and reliability. These solutions have documentation and written explanations as to why they meet those parameters. The two letters demonstrate the team's awareness of the diversity of the audiences. The written and photographic documentation is clear, of good quality, and is presented in an understandable format. The completed project shows a great deal of coordination among team members.

3 Points  =  The student makes limited contributions to the team, assisting to some extent in planning, research, testing and evaluating methods. The experimental design, while fundamentally sound, could be improved through further research and/or improvements in technique. The submitted report has stylistic flaws in its written and/or photographic documentation. The proposed methods were evaluated, but the evaluation of other methods was superficial. The proposed solutions are plausible, but lack the research or documentation necessary to enact them with a high degree of confidence.

2 Points  =  The student makes little contribution to the team, with little impact on the final product, experimental design and evaluation. The experimental design is fundamentally flawed through lack of research, producing information of questionable value. The submitted report does not follow the prescribed format, missing some parts and/or showing little coordination among other parts of the project. Evaluations of the various methods show little understanding of how redox reactions can be slowed in steel products and may even reflect misrepresentations of how corrosion may be stopped. Research on pertinent parameters is either shoddy or missing. A solution is proposed, but it is not back up by solid experimental evidence or documentation. Written and photographic documentation is sparse and presented haphazardly. The two letters show no understanding of the need to distinguish between audiences. There are numerous stylistic and grammatical errors throughout the report. Team members' attempts at coordination are not evident in the project.

1 Point  =  The student makes no contribution to the team effort. The experimental design has severe fundamental flaws or is not carried out at all. No corrosion reducing method was proposed. Or, if proposed, no reasons based on experimental evidence were given for the proposed method. The submitted work is incomplete, with little regard given to overall format, stylistic considerations, or grammar. Written and photographic documentation are incomplete or missing. Student writing is disorganized and has little substance. A lack of coordination among team members is evident throughout the project.

Keywords:

PHYSICS
MODELS AND CONSTRUCTION
EXPOSITION
TECHNICAL WRITING
CORRESPONDENCE
CALCULATION

CHEMISTRY
LAB EXPERIMENTS
STATES OF MATTER
TECHNOLOGY INTEGRATION
OXIDATION

Grades:

Kg [] - 1 [] - 2 [] - 3 [] - 4 [] - 5 [] - 6 [] - 7 [] - 8 [] - 9 [X] - 10 [X] - 11 [X] - 12 [X]

ICLE Application:

D

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