Biology-Chemistry High School SMILE Meeting
28 September 1999
Notes Prepared by Earl Zwicker

Ken Schug (IIT)
showed and passed around a most curious experiment. He mounted in a small box (about 3x6 sq in), a piece of paper two lines of the same words, one line directly below the other. Each line read: URANIUM OXIDE, but on the top line the word OXIDE was printed in red and in the bottom line, blue. We took turns viewing the words through a glass rod, about 3/8 inches diam and 3 inches long, held on the paper, in direct contact with one line of words. When we moved the rod down to the line below, we were amazed to see that ...

Ed Scanlon (Morgan Park HS)
showed us how to change "orange juice" into a "strawberry float." (handout) He placed a beaker with a solution in it into the middle of a large tray. It had the color or orange juice. He then quickly poured a colorless liguid into it, and it immediately bubbled up and turned from orange to red! Neat! But how does this work? Why does it happen!? Ed told us the "orange juice" was made by mixing 100 gm baking soda into 200 ml water in a 500 ml beaker. Add 3 good squeezes of dish soap and mix well. Add about one tablespoon of glycerin and stir well. Add methyl orange solution (an acid-base indicator) to give the mixture an orange juice color. This was the "orange juice" that we saw. It was orange in color because the baking soda is basic, giving the solutin a pH greater than 7. Methyl orange has an orange color in a basic solution. When Ed added the colorless liquid, he was adding about 100 ml of HCl to the "orange juice." The following reaction occurred:

NaHCO3 + HCl -> NaCl + H2O + CO2 (gas).

The solution turns from basic to acid, shifting the pH to less than 7, and turning the color of the methy orange indicator to a pink-red, "strawberry." The CO2 bubbled up as a gas. Soap and glycerin mixtures are used for blowing bubbles that will last, so the bubbles foam up and it looks like a "soda." What a good way to motivate student interest in chemistry! Thanks, Ed!

Pam Moy (Morgan Park HS)
passed out materials to us, and described the membrane and fluid mosaic model of a cell. With some guidance from Pam, we then used the materials to create 2-D models of cells on paper, helping us to understand better and remember this cell model. Very nice!

Karlene Joseph (Lane Tech)
showed us a part of a video tape of a Star Trek show. The characters were involved in a discussion of what constitutes life, with an android (synthetic "human") wondering about him-it-her self. Karlene then got us involved in a very intertesting discussion of what constitutes life and how ethics, science, and religious beliefs are all involvled in such life issues as cloning, artificial reproduction of human cells, etc. She certainly showed us how her students can be motivated; we certainly were! Great!

Thanks to Pam Moy for the notes!