The outline: Combustion Demo, Chemistry of Attraction, Evaporation.

I still needed a demo or a lab this week, and although I didn’t have any good ideas for something solution related, I thought that Valentine’s Day was a good excuse to do a demo involving candy. I did a simple combustion reaction, where you decompose KClO3 with heat, and then add any thing with sugar or starch. There is a good description here. I used the conversation hearts, and then I did a pencil (the graphite gets left behind). The combustion is a very bright, light purply-pink, and it makes a cool sputtering sound, a lot of smoke, and the smell of burnt marshmallow. I originally saw this done with a gummy bear.

I did not link it to my curriculum. This was shameless pandering to my students with bangs and flashes. That is one of the reasons I became a chemistry teacher.

For the chemistry of attraction, I talked about phermones, the sense of smell, and attraction in human relationships. This was an attempt to get relevant. I figured sexual attraction is always interesting to people. It is a little off topic, but interesting. I wanted to have an article for them to read, instead of having me summarize the topic, but all the articles I found were either really lame and unscientific, or really technical and difficult for high school readers. In the end, I brought it around to phase changes by talking about sweat evaporating (this is how the phermones get from our skin into someone’s nose). We then talked about  how evaporation cools things down, which is one of my content goals for the solutions unit.

I also offered them all some candy conversation hearts. I had a big bag.

Overall it was an engaging day for them. I could tell they were interested in the ideas presented, and the attraction thing did make evaporation more interesting to them. The biggest problem was that it was all very teacher led. Something to improve for next year.