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.
Each spring my Local Section of The American Chemical Society (ACS) hosts a rigorous two part exam as part of the selection process for the The International Chemistry Olympiad (IChO). The lab practicals on the exams are presented as problems. No procedure is given. Students must use their chemistry knowledge and lab experience to devise a plan and solve the problem. The best part is that the released exams come with lists of materials and equipment, helpful hints to the proctors, and solutions! This is a great source for Inquiry-Based Lab Practicals.
In Chemical Mystery #5, I used chemistry to give the illusion that water can be lit on fire. Here is the solution to that mystery.
The video displays a neat trick you can do for your students. What do you suppose is the secret behind this trick? Hint: It has to do with chemistry!
Check out the solution to Chemical Mystery #4: The Case of the Misbehaving Balloon!
This POGIL- Like density activity is suitable for online instruction.
One day during class I presented the disappearing rainbow demonstration and explained the chemistry behind it. After doing so, I had a student ask me if a particular bartending trick called “rainbow shots” was done in a manner similar to the way the disappearing rainbow demonstration is performed.
A paper square rubbed with graphite on one side is placed at the interface between two immiscible liquids, hexane and water.
A cast iron bomb is completely filled with ice water, then placed into a dry-ice/acetone slush and covered with a wooden box. When the water in the bomb freezes, the cast iron bomb explodes, breaking into several pieces, and destroying the box in which it was placed.
