I am uncertain what it is I am suppossed to talk about here so I'm just gonna go with the idea I was having right after we did the lab. For my chemistry students they were rather disapointed that we were unable to do the splint tests with the apparatus we used. We tried it but there was no reaction at all. I really wanted to set up the Hoffman apparatus, but it is apparently broken. I will order another soon but I don't think we can support it given the finances these days. We'll see. Anyway, a demonstration using the Hoffman device would be really nice after doiiing this lab using the small pippettes as electrodes. I was thinking that the team that finishes first and answers the questions all with good results could be in charge of running the demo. As a first year chemistry teacher I am barraged with students asking to blow stuff up. Of course it isn't reasonable, but a few minor combustion reactions would be really nice! The Hoffmann would go along with this lab very nicely!
Thu, 01/17/2013 - 21:13
Hey Kevin,
I like your suggestion about giving the students a motivation to get through their work so they can run the Hoffman experiment. One concern I would have is some groups rushing through it or faking it just to do the Hoffman. Of course, we the teacher would make that judgement to prevent that from happening. Check out these videos I will share with my class.
https://www.youtube.com/watch?v=OTEX38bQ-2w
https://www.youtube.com/watch?v=fJ5zD-yTwh0
Mon, 01/21/2013 - 20:06
Hi Kevin, thanks for bringing up this subject. My students definitely perk up when I say, "and this could blow up a car." Is there an outdoor area that you could use for small activities that create explosions or to make rockets? I'm thinking about making a rocket and using this activity for the project.
Mon, 12/10/2012 - 13:40
Hi Kevin! Some of the most memorable parts of high school chemistry are explosions and color changes! The Hoffman apparatus is great – when it works - because of the relatively large volumes of gas it can produce. If you are brave, you could do the hydrogen balloon demo: http://www.nuffieldfoundation.org/practical-chemistry/exploding-balloons
The periodic table of videos also features some exploding hydrogen: http://www.periodicvideos.com/videos/001.htm.
Good luck!