Addition of a white solid to a green solution causes the solution to separate into some truly beautiful colors...
Tom Kuntzleman loves to share chemical mysteries and that inspired me to create a list of mysteries that are appropriate for the main topics covered in IB Chemistry. In this blog post I'd like to share some detail about how I modified the mystery of the burning water.
In Chemical Mystery #7, a can of Coca-Cola was observed to sink in one container of water and yet float in another! This trick made use of the fact that the density of water changes with temperature.
Q: Does an unopened can of soda pop float or sink in water?
A: It depends!
See if you can figure out what is happening in this twist on the classic floating-and-sinking soda can experiment.
Inspired by Tom Kuntzleman*, I started using mysteries in my chemistry curriculum this past year. The first mystery I shared with my students was burning water. While my magician skills aren't perfect, I was able to get the students asking questions and proposing hypotheses. For my IB students, it really allowed me to delve into a number of topics (e.g. combustion, intermolecular forces, polarity, density). And thus an idea was born: Using one mystery per topic. In this blog post I'll discuss my beginning effort to find or develop a mystery for each topic within the IB Chemistry curriculum.
Solution to Chemical Mystery #6 is presented. Also, concepts related to the chemical can crush demo are briefly discussed.
Can you figure out how this experiment works?
How can I engage my students (and myself) for the last half of the semester? I read recently that the human attention span in 2015 is 8.25 seconds(link is external), which is down from 2000’s 12-second span. Currently, we are just beneath goldfish, who can attend to one thought for 9 seconds. I’m not sure of the methods of the research study, and I maintain a level of healthy skepticism. However, I admit my thoughts often spring from topic to topic like a bubble gum machine bouncy ball.
One of my favorite things to talk about with my colleagues is the use of lecture demonstrations in teaching. There seems to be a push in my district to stop using chemicals whenever possible and get to computer simulations and video in place of wet chemistry. I don’t think they are thrilled with me since I can’t envision ever taking the chemistry out of chemistry.
Flinn Scientific has a great elearning video series. Many of the videos have master teachers demonstrating some great labs and techniques that they do in the classroom.