Have you ever wondered where the cloud comes from when dry ice is placed in water? If you think the answer is “atmospheric water vapor”, be sure to read this post because experimental evidence suggests that this explanation is wrong.
Solution to Chemical Mystery #8, and...a challenge!
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. See the video below.
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.