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Macromedia Flash. Use of Macromedia Flash to Create a Web-based Tutorial for Inorganic Qualitative Analysis By Prem D. Sattsangi, Ph.D. and † Christopher L. Byers ( Programmer ). Chemtrek , by Stephen Thompson Solutions and Reactions. Study of 14 Unknown (UK) aqueous solutions
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Macromedia Flash Use of Macromedia Flash to Create a Web-based Tutorial for Inorganic Qualitative Analysis By Prem D. Sattsangi, Ph.D. and †Christopher L. Byers (Programmer)
Chemtrek, by Stephen Thompson Solutions and Reactions • Study of 14 Unknown (UK) aqueous solutions • 12 Colorless UK • 1 Blue UK (CuSO4) • 1 Yellow UK (FeCl3)
Principles to be taught • Acidity, Basicity, or Neutrality of Unknowns (UK) (Universal Indicator (UI) test) • Water insolubility of reaction products (Binary-mixing of UK, to prepare an “Ion Reaction Chart”) • Volatility of NH3(aq) (Compared to non-volatility of other basic samples, Na2CO3, Na3PO4, and NaOH)
An Economical and Eco-friendly Exercise • UK samples, ~1.5 mL, are stored and used in *micropipets. (*~3 mL capacity plastic bulbs with a long stem) [*SAMCO TRANSFER PIPETS] • Tests need only one drop of each reagent. • Tests are performed over a plastic sheet cleaned by washing with water. • Two students use one set. Set of 16 UK Samples and reagents
Chemtrek, by Stephen Thompson Ion Reaction Chart First day of the lab • pH test (UI) • Colored/colorless • samples • Soluble products • Insoluble precipitates • Digesting all this in ~ 1 hr,Pretty overwhelming!
Chemtrek Second day of the lab Expectations from the student: Identify a set of 8 unknowns Unknowns are selected from 17 colorless samples. 6 out of 12 Samples used by students, 1 out of 2 *Cations and 1 out of 4 *Anions. [*More challenging] [Binary mix UK samples with 12 known solutions, compare with the ion reaction chart for pH and solubility] Identification, A formidable task!
Revised Approach “pH Tests” Universal Indicator Test First day of the lab • Colorless UKs only • pH test Test UI UK
Revised Approach “Chemical Reactions” • Survey of insoluble precipitates • Writing chemical reactions Develop a clear understanding of solubility rules and chemical reactions First day of the lab (An abbreviated chart)
Revised Approach “The Roadmap” UK HCl, AlCl3, Pb(NO3)2, HNO3, H2SO4, Al(NO3)3 Acidic Samples Easy Identification Second day of the lab Reagent Na2CO3 (+) white ppt (+) gel, bubbles (+) bubbles Pb(NO3)2 AlCl3, Al(NO3)3 HCl, H2SO4, HNO3 AgNO3 KI AgNO3 (-) colorless (+) white ppt (+) yellow ppt (+) white ppt (-) colorless HCl AlCl3 Al(NO3)3 confirmed H2SO4, HNO3 BaCl2 (+) white ppt (-) colorless H2SO4 HNO3
Improved Student Satisfaction • Chemtrek Procedure: • Most students could identify 2-3 of the 8 UK samples in the 3 hour lab. • Resulting in a frustrated class • Roadmap Approach: • Most students identify all 8 UK samples in less than an hour. • Remaining lab time is more profitably used in writing chemical equations. View Flash