Chem 13 News: Teaching Information for the New Year

Feb 2, 2001 - by Brian Rohrig, p 17. Microscale Gas Chemistry, Part 14: ... by Bernard R. Glick and Cheryl L. Patten, pp 1, 4–5. It's Elementary, Dr...
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Chem 13 News: Teaching Information for the New Year by Kathy Thorsen

Winter is the ideal time to curl up in front of the fire with past issues of Chem 13 News. This review highlights articles published during the first six months of the new millennium; January through May 2000. In these issues you will find information on hazardous waste removal, word search and crossword puzzles, and laboratory activities that review titration, balancing equations, stoichiometry, and atomic theory and bonding. In addition, several microscale experiments and demonstrations are described that illustrate gas law principles. Cleaning Up the Local and Global Environment Two articles about hazardous waste can be found in the January and March 2000 issues. “Hazardous Chemical Removal—for Science Teachers” tells of an Ohio teacher’s journey to clean up chemistry laboratories. Cliff Schrader shares his stories from the early years when he worked to reshelve chemicals and dispose of unwanted bottles (including one containing picric acid) to the present collaborative effort by

Ohio schools to get rid of their hazardous chemicals. According to Schrader, hazardous waste cleanup in schools needs to be a statewide effort, and he outlines a procedure to execute such an effort. One of his suggested resources is the safety presentation given by Larry Flinn of Flinn Scientific. I agree that this is an eye-opening experience that could motivate teachers to pursue a cleanup project. Many states have started programs to educate science teachers about hazardous chemicals (including my own state of Wisconsin) but all could learn by reading about the success Ohio schools have had in implementing a statewide Hazardous Waste Removal Project. “Phytoremediation: Cleaning the Environment Using Plants” by Bernard R. Glick and Cheryl L. Patten also focuses on hazardous wastes. The authors describe the concept of phytoremediation as well as specific forms of this process in which plants are used to remove heavy metal contamination from the soil. A detailed description of the use of plantgrowth-promoting bacteria to offset the toxicity of heavy metals in plants is also presented.

Chem 13 News Featured Articles

Taking the Perplexity out of Puzzling Concepts January 2000, No. 281 Hazardous Chemical Removal—for Science Teachers, by Cliff Schrader, p 6 A Transition Puzzle to Start the New Millennium, by George Hickling, p 1, 15 Demonstrating That Hot Air Is Less Dense Than Cold Air, by Brian Rohrig, p 17 Microscale Gas Chemistry, Part 14: Experiments with Silane, by Bruce Mattson and others, pp 8–10 February 2000, No. 282 Analogies to Help Explain the Magnitude of the Avogadro Constant (Avogadro’s number), by Linda Farber, pp 10–11 March 2000, No. 283 Phytoremediation: Cleaning the Environment Using Plants, by Bernard R. Glick and Cheryl L. Patten, pp 1, 4–5 It’s Elementary, Dr. Watson, by Gerry Toogood, pp 5, 17 Chemistry Compounds Crossword, by Randal Henly, p 13 April 2000, No. 284 A Fifth Year (Grade 11/12) Elements Crossword, by Randal Henly, pp 4–5 A Small Tweak on an Old Favorite Demonstration, by James Cherry and Kevin Parmerleau, p 9 Microscale Gas Chemistry, Part 15: Experiments with Methane, by Bruce Mattson and others, pp 12–18

Linda Farber presents a number of ways to help students appreciate how enormous the infamous number 6.022 × 1023 is. In “Analogies to Help Explain the Magnitude of the Avogadro Constant” she has compiled a list of analogies from introductory chemistry textbooks and organized them according to themes such as money, food, time, size, and water. Many analogies could easily be converted into a dimensional analysis problem for small groups or into a challenge problem. For example, I included a bonus problem on the mole test, asking students to determine how long it would take to spend one mole of dollars if they spent one million dollars per second. Several crossword and word search puzzles offer students intellectual “fun” activities for those long winter months. The cover of the January issue shows “A Transition Puzzle to Start the New Millennium”, by George Hickling. This word search utilizes the symbols and corresponding element names to spell out a message that could be a “transition” for a class discussion on oxidation states. “It’s Elementary, Dr. Watson”, by Gerry Toogood is a crossword puzzle that uses only element names of 4, 5, or 6 letters. Both of these puzzles include answers within the same issue. Two crossword puzzles by Randal Henly incorporate more challenging clues. “A Fifth Year (Grade 11/12) Elements Crossword” includes 62 clues pertaining to the elements and “Chemistry Compounds Crossword” gives 44 clues about compounds and related concepts. Answers for Henly’s puzzles are in the subsequent issues.

May 2000, No. 285 The Band Teacher’s Lab, by Glen Loveridge, pp 1, 12–13

Experiments Are FUNdamental

It’s a Gas!!, by Alan Slater, pp 6–7

Two examples of experiments that can be used in second-year chemistry classes to review fundamental concepts

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Journal of Chemical Education • Vol. 78 No. 2 February 2001 • JChemEd.chem.wisc.edu

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as well as laboratory technique are in the May 2000 issue. Glen Loveridge conducts “The Band Teacher’s Lab” with the remaining students when the band students are away. This experiment offers practice in titration as the students determine the amount of water in the formula of sodium carbonate. Loveridge gives permission to copy the ready-to-use lab report forms, which include introduction, purpose, method, data table, and calculation sections. Another straightforward titration lab by Loveridge is in the November 1999 issue (1). “It’s a Gas!!” is a microscale lab experiment that the author says will review a first-year chemistry course in five minutes. The reaction involves the production of hydrogen gas from magnesium and hydrochloric acid in a syringe. It incorporates concepts on the gas laws, balancing equations, stoichiometry, acids, limiting reagents, percent yield atomic theory, and bonding. Slater shares a complete write-up including prelab and analysis questions, diagram, and answers to all questions. I have used a similar macroscale experiment with my first-year accelerated students, which collects hydrogen gas by water displacement in a graduated cylinder. If this procedure provides comparable results, I will gladly replace the old procedure with this one (less is more!). Visualizing Gases Brian Rohrig shares a method for “Demonstrating That Hot Air Is Less Dense Than Cold Air”, which requires only three materials—a wooden board, electric drill to make about 20 holes running down the center of the board, and wooden country matches. Directions for conducting the demonstration, safety issues, and concept application are discussed. The well-known can-crushing demonstration (2) is the focus of “A Small Tweak on an Old Favorite Demonstration” by James Cherry and Kevin Parmerleau. The article describes

a serendipitous event that allowed students to “see” the vapor pressure reduction inside the can. Meyers and Yee (3) have described a similar demonstration using a scaled-up approach. Another recent article in this Journal by Sanger, Phelps, and Fienhold (4) discusses the use of a computer animation to help students understand the relationship between the kinetic molecular theory and the can-crushing demonstration. Bruce Mattson has contributed another set of experiments to his Microscale Gas Chemistry series that began in October 1996. Part 14: Experiments with Silane and Part 15: Experiments with Methane contain directions and illustrations for the production of each of these gases in plastic syringes along with several microscale experiments to be used as demonstrations or laboratory activities.1 Note 1. The entire Microscale Gas Chemistry series is available in edited form, including color photographs of many of the experiments, at http://mattson.creighton.edu/Microscale_Gas_ Chemistry.html.

Literature Cited 1. Loveridge, G. Chem 13 News 1999, 279, 21–23. 2. Shakhashiri, B. Z. Chemical Demonstrations: A Handbook for Teachers of Chemistry, Vol. 2; University of Wisconsin Press: Madison, WI, 1985; pp 6–8. 3. Meyers, R. D.; Yee, G. T. J Chem. Educ. 1999, 76, 933. 4. Sanger, M. J.; Phelps, A. J.; Fienhold, J. J Chem. Educ. 2000, 77, 1517–1519.

Kathy Thorsen teaches at Menomonee Falls High School, N84 W16579 Menomonee Avenue, Menomonee Falls, WI 53051; [email protected]; [email protected].

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