Would You Drink This Water?

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Would You Drink This Water?

• A Project Lab in the First Year Course

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A Traditional Experiment Methods of Volumetric
Analysis
a typical cookbook experiment
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Beyond the Basic Goals...

• Demonstrate how principles of chemistry are used
  across disciplines.
• Work collaboratively from a base of independent
  competence.
• Develop critical thinking and problem solving
  skills.

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Project Labs

• Follow traditional skill building labs.
• Expect students to apply what they have learned
• teams design their own procedures
• Involve open-ended or complex problems requiring
  collaboration.

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Beautiful Lake Vickers...
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The Problem...
Could Lake Vickers be used as a source of potable
water? Does it meet standards set by the Safe
Drinking Water Act?
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EPAs Office of Water
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Complete Analysis Not Possible, So Focus On

• contaminants familiar to gchem students
• inorganics
• analytical techniques appropriate for gchem
• electrochemical (ISE, conductivity,)
• spectrophotometry
• gravimetry
• titrimetry

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Include Real World Methods

• VacuVials
• cuvet-quality ampoules contain reagents under
  vacuum
• snap tip to mix with sample

• wastewater engineer using
• VacuVials for phosphate analysis

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Work Collaboratively to Design Experiments...

• Kits of reagents, equipment, and basic
  instructions were provided.
• Students designed their own procedures.
• Needed more direction than anticipated.

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We Suited Up, Sampled, and Measured...

• pH
• Conductivity
• Dissolved oxygen

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Back to the labFilter the sample for total
dissolved solids analysis
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Work in teams to collect more data on...

• SO42-, NO3-, PO43-
• Hardness (Ca2, Mg2)
• Total cations
• Alkalinity
• Cl-

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Some Data...
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Reporting on the work - part I

• Three week experiment
• Too long for a single report.
• Group summary due each week for each test.
• Description of method.
• Data work up.
• Summary of results.
• Lots of errors! Rewrite required.

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Reporting on the work - part II

• Each student received all group summaries
• to use in writing individual final reports.
• Oral reports?

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Final report must answer the question Would you
drink this water?

• Evaluate safety and aesthetic quality
• EPA primary vs. secondary standards
• Do the results make sense?
• controls/standards?
• total anion charge total cation charge?
• Is there enough information?