From: Carol Smith (email@example.com)
Date: Sun Jun 22 2003 - 23:33:42 EDT
Next message: Carol Smith: "[Channel-talkchemistry] Re: Workshop 5"
I absolutely love the ideas in this portion!
The sig fig activity was so simple and so easy to understand -- why hadn't I thought of this before?!! The way I have illustrated this before is to do a lab (like finding the thickness of aluminum foil given the density) and having students put their answers on the board. The # of sig figs always vary without prior instruction, of course. This gives us the opportunity to examine the ruler and balance to determine the limit of precision, and to discuss how that relates to the final calculated answer.
The water equilibrium demo was also simple and effective -- illustrating that amounts of reactants and products don't change once equil. has been established.
And the pH string demo was simple and visually effective, also.
All of these are easy on the budget!!
One additional idea to illustrate electrolytes is passing an electric current through a large whole pickle, which of course has been stewing in several electrolytes in the jar. It glows neon green and puts out a putrid smelling smoke, but the students love it and don't forget that without electrolytes in the pickle, that current wouldn't flow.
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