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2003
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In the Laboratory
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Comparing the Titrations of Mixed-Acid Solutions Using Dropwise and Constant-Flow Techniques
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Paul Charlesworth, Matthew J. Seguin, and David J. Chesney
Department of Chemistry, Michigan Technological University, Houghton, MI 49931-1295
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November 2003
Vol. 80 No. 11
p. 1311
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| Abstract |
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A mixed-acid solution containing hydrochloric and phosphoric acids was used to determine the error associated with performing a real-time titration. The results were compared against those obtained by performing the titration in a more traditional dropwise addition of titrant near the equivalence points. It was found that the real-time techniques resulted in significantly decreased analysis times while maintaining a low experimental error. The constant-flow techniques were implemented into two different levels of chemistry. It was found that students could successfully utilize the modified experiments. Problems associated with the techniques, major sources of error, and their solutions are discussed. In both cases, the use of the constant-flow setup has increased student recollection of key concepts, such as pKa determination, proper indicator choice, and recognizing the shape of specific titration curves by increasing student interest in the experiment.
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| Supplement |
The materials available include: student procedures for both a general chemistry lab and a quantitative analysis lab, a quantitative analysis lab student questionnaire, a general chemistry lab quiz, an assessment of the labs, an instructor guide to the labs, a listing of potential error sources, and instructions for constructing a Mariotte bottle.
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 Contents |
Folder JCE2003p1311W containing instructor.doc and student.doc (Microsoft Word).
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| More Information |
Citation |
Charlesworth, Paul; Seguin, Matthew J.; Chesney, David J. J. Chem. Educ. 2003 80 1311.
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Keywords |
Acid–Base Chemistry; Analytical Chemistry; General Chemistry; Laboratory Computing / Interfacing; Laboratory Instruction; Quantitative Analysis; Titration / Titrimetry
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History |
Created:
Last Updated: |
October 2, 2003
February 28, 2005
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| Home > JCE Print > Journal of Chemical Education > Issues >
2003
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November
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1311
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