Saturday, October 13, 2007

Fall Colors

Lesson: Analyze organic compounds using solution chromatography
What Happened
: Pigments released in acetone solvent were drawn up into paper towel at differing rates

Here is another demonstration we tried this week from The Joy of Chemistry involving leaves changing color. With fall foliage season in full swing, I thought it would be fun to see if we could actually re-create the colors we're seeing all around us.

We used maple and oak leaves from our yard. In two different glass jars, the kids crushed and tore up the leaves, then covered them with acetone (fingernail polish remover from CVS). They then taped strips of paper towel to pencils and let them dangle into the solution, where the various pigments in the leaves were supposed to be drawn up via capillary action, creating different-colored stripes.

According to the book you only need to leave the solutions for a few hours. We left ours overnight. I was a little disappointed that we didn't see the bright red of the actual leaves, but you can make out some bands of brownish red and some yellow along with the bright green.

1 comment:

Anonymous said...

What an excellent way to celebrate chemistry week! It not only conveys chemistry comcepts, it shows how the scintific disciplines are interelated. I must say it doesn't include the required components of an experiment - question, hypothesis, controled variable... But it does make a fabulous descriptive investigation.