edited by DOUGLAS D SMITH Gullford Hlgh School
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Ideas from the 6th The 6th Biennial, again, proved the Smith axiom "no matter how great the conference program, it is the random interactions that make the conference exceed your expectations." I find my "batteries get recharged" by the informal discussions with old and new friends as they share their enthusiasm for teaching and the techniques they use to make their classrooms unique. T h e next few columns will give samples of what was available from our colleagues, whom we hope you will join a t future conferences. LaMaster's Touch 1) Finding the percent of water in a hydrate is a popular high school lab experiment. Nancy LaMaster found an adaotion to make the lab memorable. The usual data is gathered, hut she uses popcorn as the substance to he dehydrated. Poocorn is out into an Erlenmeyer flask and is constantly agiiated wGle the reaction vessel is heated. T o avoid having" students "taste" the chemicals, she gives the usual warnings about contaimination and prepares a "Jiffy Pop'" package while the students are doing the lab. 2) Here is the idea; it is up to you to develop a procedure in order to secure a pair. The expanders that medical doctors use while examining your nose make good rubber tubing expanders. s u ~ ~ e s t bv ed ~ano;'ia~aste"r D. W. Daniel H.S.
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Central, SC
The Katz' Meow The placing of a marshmallow in a vacuum jar and reducing the pressure is suggested occasionally as a demonstration while discussing gas laws. David suggests that instead of an ordinary marshmallow, the popular Easter marshmallow chicken he substituted. David Katz Community College of Philadelphia 34 South 11th St. Philadelohia. PA Dlll's Dillies One eentleman who sends teaching ideas faster than you can wrge them down is Dr. Dan Dill. Picking his brain is one of mv.obiectives for the 7th Biennial Conference. Here are a few of this year's ideas. 1) For that bright, inquisitive, prohlem-solver student who needs a good challenge, why not give himlher the project of separating a mixture of sand and oil (crude, motor oil, or whatever)? 2) For a Demo that never (always) works? "Connect" an 800-1000 ml flask with a ring stand. Add 600 ml H z 0 and a thermometer. Heat the bottom of the flask directlv candle. After a few min.. with a ore-massed (weiehed) " utes, by using the change of water temperature, mass of water, loss of mass of candle. calculate the heat of comhustion. As-~ suming the formula fo; the candle was C20H42, have a student look uo AH comhustion in a handbook. An error of 40% is usuall; found. In the discussion that follows of the possible errors and means to control the variables, a homh~calorimeterdesign should he arrived at. After a brilliant discussion, the bottom
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of the flask can he shown which will be black with "soot." Now a basis for a Hess's Law discussion is present. 3) Cork horer-an old tip revisited. Cork borers can he used to insert class ohiecta through a stopper. Choose the borer that allows the glass tubing 6 fit inside the borer. Insert borer in the hole, insert class obiect in the horer, and then remove the borerleavingthe tubing behind. 4) Equilibrium analogy. The aoldfish analom -- -presented in CHEM Study films is well known. But how about expanding the discussion with the following diagrams and see if students can predict concentration in terms of >,
